Search

This paper establishes a test bench for a free piston expander–linear generator (FPE–LG) system coupled with the drive motor (DM) to promote the application of FPE–LG on vehicle. Firstly, it discusses the operating characteristics and output performance of the FPE–LG under the simulated operation conditions of vehicle. Meanwhile, it investigates the operating characteristics of FPE–LG under different torques and expansion times. Finally, this paper analyzes the influence of different torques and expansion times on the operating frequency of FPE–LG. The experimental results show that the operating frequency of FPE–LG is related to the expansion time and torque. The power output of the DM decreases as the torque increases, the power output of the DM increases first and then decreases as the expansion time increases. Therefore, the selection of suitable expansion time under different intake pressure plays an important role in improving the power output of the DM. The maximum of the peak power output of DM is about 25.8 W, when the intake pressure is 4 bar, the expansion time is 30 ms and the torque is 0.00571 N m.

Two low voltage parallel full-bridges are proposed for the power supply of a two-axis electromagnetic micro-actuator. GaN FETs are chosen for these converters to achieve high efficiency while switching at high frequencies. The control strategy implements the phase shift between two branches of each full-bridge and the interleaved phase between two full-bridges, which reduces the load current ripple and increase the frequency of input and output current ripples. These properties help us miniaturize filtering coils and decoupling capacitors associated to the converters. The test bench that highly integrates the micro-actuator and converters was fabricated. Simulation and experimental results are compared for analysing and validating the integration and the proposed control strategy.

PV-TEG PV–TEG hybrid system is widely discussed nowadays, as an alternative way to maximize solar radiation energy which is from both of its light and heat. In recent years, the idea of using thermoelectric generators (TEGs) to extract energy from heat waste has increased with applications varying from milliwatts to kilowatts. To form a circuit, numbers of TEG modules can be connected in series and/or parallel configuration to produce the required voltage and/or current. In the PV-TEG PV–TEG​ systems, due to operating environments, each TEG module’s power generation is subject to temperature mismatch. There is also considerable variability in the electro-thermal output and mounting pressure of each TEG module in a circuit, resulting in a significant inconsistency. Therefore, when each TEG in the array is active, a varying electrical operating point will occur at which peak energy can be obtained and problems with lower power output will occur. In this work, an individual TEG module test method was used to measure and analyze data from specific types of TEG, and a record of the maximum power output under different temperature variations is obtained. Then, the performance of the TEG system is measured and evaluated with a test bench where the modules are attached at different backside areas of generic PV panels. The non-uniform heat distribution condition created in the experiment showed an average 33 % drop in power production from the maximum power that would be available in case each TE series circuit operates under uniform heat distribution. This experimental finding demonstrates the problem and the outcomes discussed in this paper validated a thorough examination of the effect of nonuniform operating temperatures on a range of thermoelectric generator’s energy output.

Low temperature district heating (LTDH) is a key technology for the efficient integration of renewable energies and waste heat in our energy systems. Energy system studies indicate that a further development of LTDH systems is needed for a decarbonization of the heating sector and to reach the climate goals, but is also put in question. To face these challenges, research on innovative district heating concepts is required like the feed-in of decentralized renewable energy or the design of new modes of operation. Against this background, the new experimental facility District LAB is set up serving as a test and development platform for innovative district heating systems in close cooperation with collaborates from industry and research. By using the facility, it is targeted to investigate the system behaviour of flexible heating networks, to conduct component tests and to develop innovative control concepts for new management strategies. To reach these goals the District LAB consists of a flexible heating grid, a pipe test bench for mechanical tests and management respectively control units. This way the possibilities of the already existing facilities are expanded. Compared to tests in real operating district heating grid (demonstration) the experimental environment is more flexible since no public utility mandate is connected to the facility. A first started project comprises three different fields of research as investigations of new operational strategies or digitalization, tests of components and the development or validation of simulation tools. The results of the project and the knowledge generated at the District LAB will make a significant contribution to the decarbonization,​ transformation and digitization of district heating. The paper presents a more detailed description of the District LAB and the started research activities to foster the discussion about needed research and to invite possible partners from academia and industry for future cooperation.

This work presents a mathematical modelling of a proton-exchange membrane fuel cell (PEMFC) system integrated with a resistive variable load. The model was implemented using MATLAB Simulink software, and it was used to calculate the fuel cell electric current and voltage at various steady-state conditions. The electric current was determined by the intersection of its polarisation curve and applied as an input value for the simulation of the PEM fuel cell performance. The model was validated using a Horizon H-500xp model fuel cell stack system, with the following main components: a 500 W PEM fuel cell, a 12 V at 12 A battery for the start-up, a super-capacitor bank to supply peak loads and a 48 V DC-DC boost converter. The generated power was dissipated by a variable resistive load. The results from the model shows a qualitative agreement with test bench results, with similar trends for stack current and voltage in response to load and hydrogen flow rate variation. The discrepancies ranged from 2% to 6%, depending on the load resistance applied. A controlled current source was utilised to simulate the variation of fan power consumption with stack temperature, ranging from 36.5 W at 23 °C to 52 W at 65 °C. Both model and experiments showed an overall PEMFC system maximum efficiency of about 48%.

The no-load drag torque is a crucial factor in the design phase to estimate the power required by the electric motor in electro-mechanical actuators (EMA). This paper focuses on the analysis of the drag torque contribution generated in preloaded double nut ball screws of EMAs. In literature its value is commonly estimated with a linear relationship with respect to the preload level. However, many other parameters play a role in determining the friction torque, such as operating speed, temperature and geometry. A sensitivity analysis on these parameters is presented by means of simulation results obtained from a high-fidelity multibody dynamic (MBD) model, capable of describing the full three-dimensional dynamics of each subcomponent and the presence of full film, mixed or boundary lubrication between mating elements. The results have been interpreted with a physics-based approach highlighting a strong dependency of the drag torque on temperature basing on the lubricant’s viscosity. This parameter also influences the drag torque speed dependence, which resulted to be more pronounced for low operating temperatures. An experimental test bench is being constructed to validate the model results.

Industrial denitrification catalyst monoliths are regularly tested in controlled lab-scale conditions to quantify their activity. As mass transfer phenomena occurring inside the channels of the monoliths have an important impact on the global denitrification kinetics, activity measurements must be conducted in well-known conditions in terms of sample geometry and gaseous flow regimes, among others. The lack of accurate mass transfer correlations for the complex flows at stake however prevents any accurate generalisation of the test results. In this paper, we propose a semi-empirical method for the quantification of contribution of mass transfer to the global denitrification kinetics for any given test bench. It is based on the experimental adjustment of mass transfer correlations presenting a suitable form. Mass transfer can therefore be decoupled from the intrinsic kinetics and large ranges of conditions can be covered by conducting a limited number of measurements., SCOPUS: ar.j, info:eu-repo/semantics/published

[EN] After the diesel emissions scandal, also known as Dieselgate, Direct Injection Spark-Ignited (DISI) internal combustion engines (ICE) appears as the most promising alternative to mitigate the harmful tailpipe emissions from passenger cars. In spite of that, the current ICE technologies are not enough to achieve the fuel consumption/CO2 emissions targets set by the new transportation legislation (4.1 L-gasoline/100 km, 95 gCO(2)/km for 2021). In this complex scenario, the electrification of the powertrain using high efficiency electric motors and battery package together with sophisticated DISI engines appears as potential solution to meet these requirements. The aim of this work is to study the fuel consumption and pollutant emissions in transient conditions from a passenger car equipped with a variable compression ratio (VCR) DISI engine and electrified powertrain technologies. The vehicle behavior was simulated by means of a 0D GT-Suite model fed by experimental results obtained in an engine test bench. Mild hybrid electric vehicle (MHEV) and full hybrid electric vehicle (FHEV) architectures using a VCR DISI engine were studied. Moreover, an optimization methodology is presented to select the best vehicle configuration in terms of hardware and control strategies by means of a design of experiments (DoE). The results show that VCR allows a fuel improvement of 3% with respect to the conventional DISI fixed CR along the worldwide harmonized light vehicles test cycles (WLTC). The benefits found when combining the VCR technology with hybrid powertrains are even higher. In this sense, the fuel improvements were higher as the electrification levels increased, with 8% for MHEV-VCR and around 20% for FHEV-VCR. In terms of emissions, the two clear benefits with FHEV-VCR were the reduction of particle number (PN) and unburned hydrocarbons (HC) of around 60% and 15%, respectively, as compared to the conventional DISI., The authors acknowledge FEDER and Spanish Ministerio de Economia y Competitividad for partially supporting this research through TRANCO project (TRA2017-87694-R). The authors also acknowledge the Universitat Politecnica de Valencia for partially supporting this research through Convocatoria de ayudas a Primeros Proyectos de Investigacion (SP20180148).

[EN] Knock control represents one of the most critical aspects to reach optimal thermal efficiency in spark ignition engines, and its research is crucially important because it determines thermal efficiency, engine durability, and power density, as well as noise and emission performance. In this paper, a spark advance control based on a map learning technique is combined with a knock estimator to maximize the engine efficiency while keeping the knock probability below a desired limit. The proposed controller is experimentally validated on a production spark ignition gasoline engine test bench, and compared with a conventional spark advance controller in both, steady and transient conditions. From experimental results, a benefit in terms of thermal efficiency, control stability and engine security are achieved. The results show that the proposed method is capable of regulating the knock probability to a target percentage with low spark advance and thermal efficiency dispersion than the conventional controller., Irina A. Jimenez received a funding through the grant GRISOLIAP/2018/132 from the Generalitat Valenciana and the European Social Fund.

[EN] Recent investigations demonstrated that the real-world driving conditions differ from those proposed in the homologation cycles. This provokes that the emissions levels in real-life conditions exceed the normative values, as shown in the recent scandal related to the NOx emissions from the passenger cars equipped with diesel engines. On the other hand, the upcoming emissions regulations will limit the CO2 emissions to very low levels, which demands a further optimization of the existing technology. One way to reduce the NOx and CO2 emissions is by electrifying the powertrain in a certain degree. The objective of this work is to evaluate the potential of implementing a parallel (P2) hybrid architecture in a compact car (class C) equipped with a diesel 1.6 Euro 6d-temp engine to reduce the emissions and fuel consumption in homologation and real-life driving cycles. This has been done using a OD numerical vehicle model and the experimental engine maps of fuel consumption and emissions measured at steady state conditions. After that, the transient conditions were simulated in homologation cycles and real-life driving cycles measured by the authors in Spain. The numerical model was validated against experimental tests carried out in an active engine test bench, evidencing differences below 4% under the worldwide harmonized light vehicles test cycle (WLTC). In the real-life cycles, the hybridization of the powertrains improves the fuel consumption for all types of driving cycles (urban, combined and highway). The major benefits are obtained in urban driving cycles, with gains up to 50% in fuel consumption and CO2 emissions. In addition, the improvements in real-life conditions are higher than in the urban phase of the homologation cycles. On the contrary, combined real-life cycles (urban + rural + highway) show lower benefits than the homologation cycle. This is due to different energy management strategy that needs to be adapted to each driving situation. Lastly, it was found that, contrarily to the case of the homologation cycle, the NOx emissions are not reduced with the hybridization of the diesel powertrain in real-life conditions. Thus, to achieve 2021 CO2 target (95 g/km) and to reduce aftertreatment systems in diesel engines, other vehicles technologies need to be added to the full hybridization., The authors acknowledge FEDER and Spanish Ministerio de Economia y Competitividad for partially supporting this research through TRANCO project (TRA2017-87694-R). The authors also acknowledge the Universitat Politecnica de Valencia for partially supporting this research through Convocatoria de ayudas a Primeros Proyectos de Investigacion (PAID-06-18).

In this paper an analytical method for studying the free response of continuous vibrating systems with distributed and possibly non-proportional viscous damping is proposed. The most general case the method refers to is a piece-wise homogeneous Euler-Bernoulli beam, with lumped elastic and inertial elements and subjected to tensile load. The practical application of the method to a contact wire is also presented, aiming at analysing its dynamic response. Contact wires are typically used in the overhead contact line of the railway electrification system but, despite their wide diffusion, their damping properties have not been exhaustively studied. This study aims at experimentally validate the analytical method to define a reliable dynamic model of overhead contact lines. The wire is modelled as an axially loaded homogeneous beam, with lumped elastic and inertial elements (i.e. droppers and clamps). A state-form expansion applied in conjunction with a transfer matrix technique is adopted to extract the eigenvalues and to express the eigenfunctions in analytical form. Experimental measurements have been carried out in the Dynamics & Identification Research Group (DIRG) laboratory of Politecnico di Torino considering two different damping scenarios, and the modal properties of the test bench have been extracted by using a linear subspace identification technique. The damping distribution is finally investigated starting from the experimental data, in order to seek for the most appropriate damping model.

Cyclone separators are widely used for dedusting of particle-laden flows in many branches of industry. A new cyclone containing several collectors was designed in modular structure to investigate the capability of particle classification of the cyclone during particle separation process. The particulate air was supplied into the cyclone in a test bench operated in suction mode under ambient temperature and atmospheric pressure conditions. The flow rate and pressure drop were measured, and the particles accumulated in the dust collectors were weighed and analyzed for each test. The changes in the overall collection efficiency and pressure drop with the flow rate were obtained. In order to determine the classification characteristics of the cyclone, the experiments were repeated in different configurations obtained by changing the locations and number of the collectors. The mean particle diameter and particle size distribution of the dust collected in each collector were acquired. Analysis of the results shows that the designed cyclone is capable of classification incoming particles into 2, 3 or 4 classes in the cyclone according to particle size. Classification performance of the configurations and influences of flow rate on this performance were also investigated. A distinct and satisfactory classification was obtained in the configuration with three collectors.

[EN] The objective of the study is to determine the behavior of the low pressure exhaust gas recirculation (LP EGR) transport phenomena in the intake manifold during engine transient operation. The investigation also analyzes the influence of the propagation of the pressure waves in the intake manifold on the engine performance. In this sense, there is a clear trade-off: long intake lines improve the engine volumetric efficiency at low engine speeds but delay the EGR transport in the system. The experiments were performed on a test bench with a 1.6 liter Euro-5 specification diesel engine. A CO2 fast tracking measurement device was setup and placed in two locations in the intake line in order to track the EGR transport in transient operation. The CO2 concentration is acquired with crank-angle resolution. Three different engine transients at constant engine speed were studied. They are extreme and worst-case scenarios in driving situations: (i) from low load to full load, (ii) from full load to low load, and (iii) from low load to medium load. In this way, it is possible to observe the behavior of the engine when: (i) leaving the EGR zone, (ii) entering into the EGR zone, and (iii) changing operating point without leaving the EGR zone. A consistent methodology that combines experimental results and a 1D model capable to predict the behavior of the engine was developed. The results obtained in this investigation show a relevant phenomenon: depending on the synchronization of the EGR and Exhaust Throttle (ET) valves, an overshoot occurs when the engine enters into EGR zone. In this study, the results show the importance of the synchronization of the valves that control the EGR strategy. Comparisons between measured and modeled CO2 concentrations lead to conclude that the EGR transport during engine transient operation is correctly predicted within a 1D engine code.

This paper faces the problem of developing an effective Condition Monitoring algorithm (CM) for Electro-Mechanical Actuators (EMA) in aerospace applications. In this view, a test campaign has been carried out in order to progressively bring the EMA near to failure, by means of a test bench suitably developed. Various indicators have been computed from measured data, for a set of the EMA's working regimes. The statistical distribution of the computed features is assessed and tracked over time. We propose an online statistical approach, based on density estimation techniques, in order to detect potential changes in the data distribution. The discovered changes are then interpreted as a modification of the EMA's health state, leading to a first building block for a complete condition assessment strategy.

This work presents various models developed and implemented within the SOPHIA European project in order to thermally characterize PV modules in a rooftop BIPV configuration. Different approaches have been considered, including a linear model, lumped elements models and models that make use of commercial software solvers. The validation of the models performed by comparing the results of simulations with experimental data recorded on a test bench over an entire year is presented and discussed on a seasonal basis. The results have shown that all the models implemented allow achieving a good prediction of the PV modules back surface temperature, with the minimum value of the coefficient of determination R2 around 95% on a yearly basis. Moreover, the influence of season weather conditions and of the incident solar irradiance magnitude on the accuracy of the considered thermal models is highlighted. The major result of the present study is represented by the fact that it has been possible to perform a better thermal characterization of the BIPV module by tuning some of the heat transfer coefficients, such as those relative to the effects of the wind velocity, and to the evaluation of sky temperature. The experimental data used for the thermal simulation of BIPV system behavior were obtained in the framework of the project Performance BIPV supported by the French research agency (ANR), within the research program ANR HABISOL. Authors are grateful to the project partners CSTB, CEA, CNRS, Transénergie and Cythelia and to the private companies that provided the materials for the test benches. Authors would like to thank the European Community that supported the SOPHIA project with the funding of FP7-SOPHIA grant agreement nº 262533.

At DLR’s QUARZ Center a test bench has been established to measure, using steady state calorimetric method, the total hemispherical emittance of cylindrical solar thermal absorber samples at temperatures up to 450 °C. Emittance measurement of solar absorber surfaces is commonly performed by direct-hemispherical reflectance measurements with spectrophotometers. However, the measurement of cylindrical samples with spectrophotometers can be considered still a challenge as integrating spheres, reference samples and calibration services by national metrology institutions are optimized for flat sample measurement. Additionally samples are typically measured at room temperature. The steady state calorimetric method does not rely on reference samples and the measurement is performed at operating temperature. In the steady state calorimetric method electrical power input used to heat the sample is equated to the radiative heat loss from a heated sample to the environment. The total emittance can be calculated using the Stefan-Boltzmann equation from radiative heat loss power, the defined sample surface area and measured surface temperature. The expanded uncertainty (k=2) of the total hemispherical emittance has been determined to ±13 % for a typical parabolic trough absorber sample at a temperature of 300 °C and a heating power of 100 W. The test bench was validated by the measurement of three samples with the spectrophotometer and the steady state calorimetric method.

[EN] Centrifugal compressor performance at low mass flow rates has become an issue in the latest years due to engine downsizing and the increase of low-end torque request. The principal drawback of this operating region is the appearance of the surge phenomenon, which is strongly affected by the compressor inlet geometry. This work is addressed to study the impact of different inlet geometries on the compressor performance, including compressor efficiency, noise emission and surge margin. An engine test bench is set up with a centrifugal compressor and both steady and transient (tip-out) tests are performed in order to obtain a complete view of the influence of each configuration. The results show a clear sensitivity of the compressor parameters to the variations of the geometry upstream the compressor inlet. (C) 2016 Elsevier Ltd. All rights reserved., Daniel Tari is partially supported through contract FPI-S2-2015-1095 of Programa de Apoyo para la Investigacion y Desarrollo (PAID) of Universitat Politecnica de Valencia.

This chapter is devoted to genetic algorithms (GAs) for mobile robot planning. Section 4.1 describes the complete algorithm for path planning and functioning of the GA and graphs as its part. Section 4.2 gives short overview of graph idea and how it is applied to represent the optimized path. Section 4.3 describes the GAs applied to path planning. Section 4.3.1 describes the general idea of GAs and basic genetic operators. Section 4.3.2 studies three modifications of the GA—classical, ( μ , λ ), and ( μ + λ ), and chooses the best one for the task of path planning. Section 4.4 the results of imitation modeling on the test bench common for all path planning methods in this book.

[EN] This paper presents a characterization methodology for vapor-injection scroll compressors (SCVI). An SCVI was characterized in a modified calorimetric test bench, which is able to control the intermediate pressure and the injection superheat independently. Based on the characterization results, the injection mass flow rate was correlated with the intermediate pressure through a linear expression, and a modified AHRI polynomial was proposed to estimate the compressor power input. The correlations were used in a simple model to predict the intermediate conditions of the SCVI installed in a heat pump prototype with an economizer. The deviations obtained for the evaporator mass flow rate, injection mass flow rate, intermediate pressure, and compressor power input were lower than 5% in all cases. The proposed methodology allows evaluating SCVI in a wide range of operating conditions, being only dependent on compressor characteristics and totally independent of the system in which it is installed., Fernando M. Tello-Oquendo acknowledges the financial support provided by the "CONVOCATORIA ABIERTA 2013-SEGUNDA EASE" program, which was funded by the SENESCYT ("Secretaria Nacional de Educacion Superior, Ciencia, Tecnologia e Innovacion") (Grant No. 2015-AR37665) of Ecuador.

This chapter describes the devices and techniques for monitoring of lead–acid batteries in modern vehicles and points out their importance for the vehicle's EEM (electrical energy management). It starts with a historic overview of battery monitoring devices followed by the system hard- and software requirements of such devices. Then, the most important BSD (battery state detection) signals communicated to the vehicle's master control unit as SoC (state-of-charge), SoF (state-of-function) and SoH (state-of-health) are explained. After summarising general requirements to BSD algorithms, different approaches, such as the Kalman Filter, are presented. Then, test bench and vehicle validation of the BSD signals is focussed on. At last, real-life experiences related to battery, EEM and electric power-supply system issues are shared before the chapter ends up with an outlook on future current sensing methods.

Long-span and lightweight floors are often prone to structural vibrations due to their low resonance frequency and inherent damping. They are easily excited by human walking or running and present a serviceability problem for persons working or living in these buildings. Tuned mass dampers can be used to improve the dynamic behaviour of such structures. The drawback of these passive damping systems is that they require high inertial damper masses and that the damping efficiency in transient phase is low. Especially for systems with resonance frequencies that change over time (due to an addition mass or a change of the structure or temperature dependant phenomena) the damping efficiency drops rapidly. Active controlled tuned mass damper can be used to reduce the inertial mass and improve the damping efficiency for a broad band of frequencies in transient phase. Several constraints, like the stability in closed loop, robustness and performance criteria and the maximum stroke and saturation of the actuator have to be considered when designing a controller for an active vibration control device. Different control strategies are analysed in this work and simulated using a 2nd and a 4th order system in order to analyse advantages and drawbacks., Procedia Engineering, 199, X International Conference on Structural Dynamics, EURODYN 2017

Variable loads to which gearboxes are subjected are considered as one of the main sources of non-stationarity in these transmissions. In order to characterise their dynamic behaviour in such conditions, a torsional lumped parameter model of a planetary gear with power recirculation was developed. The model included time varying loading conditions and took into account the non-linearity of contact between teeth. The meshing stiffness functions were modelled using Finite Element Method and Hertzian contact theory in these conditions. Series of numerical simulations was conducted in stationary conditions, with different loading conditions. Equation of motion was solved using Newmark algorithm. Numerical results agreed with experimental results obtained from a planetary gear test bench. This test bench is composed of two similar planetary gears called test planetary gear set and reaction planetary gear set which are mounted back-to-back so that the power recirculates through the transmission. The external load was applied through an arm attached to the free reaction ring. Data Acquisition System acquired signals from accelerometers mounted on the rings and tachometer which measured instantaneous angular velocity of the carrier's shaft. The signal processing was achieved using LMS Test.Lab software. Modulation sidebands were obtained from the ring acceleration measurements as well as a non-linear behaviour in case of variable loading resulted by a transfer of the spectral density from the fundamental mesh stiffness to its second harmonic. This work was financially supported by the Tunisian-Spanish Joint Project No. A1/037038/11. The authors would like also to acknowledge the project funded by the Spanish Ministry of Science and Technology and called ‘‘Development of methodologies for the simulation and improvement of the dynamic behavior of planetary transmissions DPI2013-44860”.

A heavy-ion storage ring can be adapted for use as an isochronous mass spectrometer if the ion velocity matches the transition energy of the ring. Due to the variety of stored ion species, the isochronous condition cannot be fulfilled for all the ions. In order to eliminate the measurement uncertainty stemming from the velocity spread, an intensity-sensitive and position-resolving cavity is proposed. In this article we first briefly discuss the correction method for the anisochronism effect in the measurement with the cavity. Then we introduce a novel design, which is operated in the monopole mode and offset from the central beam orbit to one side. The geometrical parameters were optimized by analytic and numerical means in accordance with the beam dynamics of the future Collector Ring at FAIR. Afterwards, the electromagnetic properties of scaled prototypes were measured on a test bench. The results were in good agreement with the predictions.

As for the recent PM regulations, a diesel particulate filter (DPF) has been one of the important aftertreatment technologies. Although the square cell structure of DPF is a generally worldwide standard, several cell designs have been proposed to reduce the pressure loss due to the soot loading as well as the ash deposition in DPF. In this study, we focused on the cell geometry using a hexagonal cell DPF and a conventional square cell DPF. In the engine test bench under nearly real conditions, these DPF performances were evaluated. Results show that, in comparison with square cell DPF, the particle number concentration of the hexagonal cell DPF decreases more rapidly, and the filtration efficiency is higher. In addition, in DPF regeneration test, independent of the inlet temperature, the regeneration rate of the hexagonal cell DPF is higher. Between two DPFs, the aperture ratio of inlet/outlet cells is different. Thus, the superior DPF performance of the hexagonal cell DPF could be explained by the difference of exhaust gas flow and soot deposition region.

Limiting yarn damage is key for a stable braiding process. The reasons for damage and its evolution during processing are discussed. To categorize damage, a classification system is introduced that allows for distinguishing the different states of damage evolution. Even though the mechanisms causing yarn damage are known, its evolution throughout the braiding process chain is not yet fully understood. A test bench mimics the loading conditions of the yarn in the machine. Thus, the damage state of yarns can be assessed offline. Improved fiber materials lead to reduced yarn damage but complicate its quantification. Test methods like liquid absorption and sensitive detectors for single broken filaments even measure the initial states of damage. An optimized rewinding process in combination with refined processing equipment and parameters reduce damage-induced braiding errors to a minimum.

A lightguide fibre–based textile collecting and delivering sun energy is developed. It aims to dramatically reduce the amount of photovoltaic cells embedded on some devices and thus competes with current organic photovoltaic cell technology. However, the use of a woven textile implies a specific and unconventional configuration of light entrance, the light being collected along the fibre length. Hence, it raises numerous challenges in terms of light collection and propagation. This study reviews the literature, exposes and addresses these challenges. Several woven structures are tested using a filtered xenon lamp to simulate the sun and a specially designed test bench. The textile's light weight and efficiency are considered since they are both significant assessment criteria.

In the last few years, the effect of diabatic test conditions on compressor performance maps has been widely investigated leading some Authors to propose different correction models. The aim of the paper is to investigate the effect of heat transfer phenomena on the experimental definition of turbocharger maps, focusing on compressor performance. This work was developed within a collaboration between the Polytechnic School of the University of Genoa (Italy) and the testing center CRITT M2A (France). In particular, an original model for the correction of compressor steady flow maps is presented and discussed. The major benefit of this method is represented by the easiness of data post-processing, the data base economy, the reduced number of geometrical and physical input parameters required and the accuracy of the solution. Besides, this model does not need an out-of-standard test bench to obtain the compressor maps. In the paper, experimental tests under quasi-adiabatic conditions developed to validate the proposed model are reported. A satisfactory agreement between measured and calculated compressor maps is highlighted.

This paper deals about an experimental application of an ORC (organic Rankine cycle) in a ceramic industry for low grade waste heat recovery. The ORC module used in this application was initially designed and constructed to satisfy the main specifications for an efficient power system, highlighting a volumetric expander with large built-in volume ratio. Furthermore, the performance of the ORC was experimentally characterized in a test bench in a previous work, achieving a maximum gross electrical efficiency of 12.32%. Taking this as a starting point, the aim of this work is to verify the performance of this ORC operating in actual industrial conditions, besides to profiting the information extracted from the application to assess its profitability. For this, the system performance is experimentally characterized in the industry, discussing and comparing the results obtained to laboratory data. From these experimental results a model of the system is developed, which allows predicting the net electrical production of the system along a typical year of operation and quantifying the energy and environmental benefits of the project. Moreover, from the electrical generation, investment costs required and industrial electricity price, a feasibility study is conducted to address the profitability of the application., The authors are indebted to the Minister of industry of 'Generalitat Valenciana' (Spain) for its financial assistance under project INIDIV2010022 and Rank (R), the ORC manufacturer, for its support in this project. Also to thank greatly the Jaume I University for its financial support under the PhD grant PREDOC/2013/28 of 'Convocatoria d'ajudes predoctorals per a la formacio de personal investigador del Pla de promocio de la investigacio de la Universitat Jaume I de Castello (Spain)'.

An ORC (organic Rankine cycle) module, designed and built for a specific CHP (combined heat and power)) application, is tested in this paper. The aim of the work is to characterize the system performance in the operating range allowed by the ORC. For this purpose, a test procedure has been conducted in a test bench. The heat source has been simulated through a natural gas boiler and a thermal oil heat transfer loop to control the temperature in the low grade range of 90 °C 150 °C. The heat sink has been developed using a dry cooler to control the hot water temperature in the range of 30 °C, corresponding to a power application, to 80 °C, of a small-scale CHP application that provides hot water at 90 °C. Thereby, the results show that the thermal power captured by the ORC, electricity and useful heat produced, increase with the rise of the thermal oil temperature and larger pressure ratios. Moreover, the expander electrical isentropic effectiveness is maximized about 70% for a pressure ratio suitable for a CHP system. The cycle efficiency slightly continues increasing for higher pressure ratios, up to a net electrical efficiency of about 8%., The authors want to acknowledge all the invaluable cooperation of Rank (R), the ORC manufacturer, for its support in this project. Also to thank greatly the Jaume I University for its financial support under the PhD grant PREDOC/2013/28 of 'Convocatoria d'ajudes predoctorals per a la formacio de personal investigador del Pla de promocio de la investigacio de la Universitat Jaume I de Castello (Spain)'.

This chapter describes how to perform power microwave transistors lifetime tests in operational conditions. The originality of this test bench is its ability to monitor automatically component performance during thousands of hours and to apply electrical and thermal stresses. This equipment is used to test high power transistors operating in pulsed mode and to record electrical parameter drifts using in-situ static and dynamic electrical characterization. The results of different aging processes of laterally diffused metal oxide semiconductor (LDMOS) high power transistors are presented

Current diesel engines are struggling to achieve exhaust emissions regulations margins, in certain cases penalizing the fuel consumption. The exhaust gas recirculation (EGR) continues to be employed as a technique to reduce NOx emissions. EGR dispersion between cylinders is one important issue when a high pressure (HP) loop is used. Different techniques have been developed in order to analyze the EGR dispersion between cylinders in an engine test bench. In this paper a methodology using the in-cylinder pressure was developed. The in-cylinder pressure was used to calculate a heat release law and combustion parameters that were used to analyze the EGR dispersion between cylinders. Engine test measurements at three different engine speeds and with three different HP-EGR configurations were performed in order to assess the developed analysis methodology. NOx emissions and fuel consumption were also compared between the different HP-EGR configurations to complete the analysis. The developed methodology was successfully used in three different operating conditions for three different HP-EGR configurations, showing the relation between the decrease in EGR dispersion between cylinders and the decrease in NOx emissions, while maintaining and, in some points, improving the fuel consumption.

In this paper the performance of an Organic Rankine Cycle (ORC) module, which was designed and built for a specific power application, is experimentally characterized. The ORC tested satisfies the main specifications for an efficient power system, highlighting a volumetric expander with large built-in volume ratio. For tests development, a monitored test bench has been used and adapted to the planned test procedure, which consisted of varying the thermal power input for different condensing conditions. Thereby, 10 steady state points are achieved and analyzed according to thermal power input, gross and net electrical powers, electrical cycle efficiencies and expander effectiveness. The results show that the ORC performances are improved for higher thermal oil temperatures, capturing more thermal power, producing more electricity and achieving better cycle efficiencies. The maximum gross electrical efficiency obtained is 12.32%, for a heat source temperature about 155 °C and a direct dissipation to the ambient. Moreover, the expander reaches an electrical isentropic effectiveness about 65% for an optimum pressure ratio around 7, being a suitable system for power applications from low grade heat sources., The authors are indebted to the Minister of Industry of 'Generalitat Valenciana' (Spain) for its financial assistance under project INIDIV2010022 and Rank (R), the ORC manufacturer, for its support in this project. Also to thank greatly the Jaume I University for its financial support under the PhD grant PREDOC/2013/28 of 'Convocatoria d'ajudes predoctorals per a la formacio de personal investigador del Pla de promocio de la investigacio de la Universitat Jaume I de Castello (Spain)'.

[EN] The behavior of small turbochargers is deeply affected by heat transfer phenomena. The external heat losses of these machines are studied and a simplified model that takes into account both radiation and convective mechanisms has been proposed. The model has been adjusted in a turbocharger test bench for two different turbochargers, later on it has been validated against experimental measurements on an engine test bench. Finally, the model has been used to estimate the most important external heat flows among the different elements of the turbocharger, showing the operative points in which external heat transfer in turbochargers cannot be neglected. (C) 2014 Elsevier Ltd. All rights reserved., This work has been financial supported by Jaguar Land Rover Ltd.

Currently, the most adequate technology for the abatement of particles coming from diesel engines is the one that employs catalytic filters. This work proposes the preparation of catalytic ceramic papers to be employed in the development of new catalytic filters. To this end, the papermaking technique was employed. The resulting papers were flexible, easy to handle and presented suitable mechanical properties to resist the tests from a test bench in which they were placed inside a metal housing, at the exhaust pipe outlet of a Corsa 1.7 vehicle. These optimal mechanical properties were obtained through the incorporation of a suspension of CeO2 nanoparticles during the papermaking process. It was found that the nanoparticles covered the ceramic fibers completely and that their excess accumulated under the form of patches. In order to promote the filter continuous regeneration, once the ceramic papers were formed they were impregnated with a cobalt salt which, after a calcination stage, produced oxidic clusters in tight contact with the CeO2 nanoparticles. The papers thus obtained exhibited a maximum soot combustion temperature close to 400°C, being T50 = 376°C for the more active catalytic ceramic paper, in the presence of NO (1000 ppm) in the feed. Even though more tests are necessary to determine filtration efficiency, preliminary experiments carried out in the test bench proved that the ceramic papers properly resisted the high gas flow rates of fumes emitted by a real diesel engine (approximately 2 m3.min-1). From the TPO experiments performed on samples of catalytic ceramic papers taken from the test bench and in tight contact with the soot retained, it was possible to obtain a maximum soot combustion temperature equal to 428°C. It was also found that the presence of ceria aggregates caused the papers to deactivate to a lesser degree after being treated at 900°C. Fil: Tuler, Fernando Esteban. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Santa Fe. Instituto de Investigaciones en Catálisis y Petroquímica ; Argentina Fil: Banus, Ezequiel David. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Santa Fe. Instituto de Investigaciones en Catálisis y Petroquímica ; Argentina Fil: Zanuttini, Miguel Angel Mario. Universidad Nacional del Litoral. Facultad de Ingeniería Química. Instituto de Tecnología Celulosica; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Santa Fe; Argentina Fil: Miro, Eduardo Ernesto. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Santa Fe. Instituto de Investigaciones en Catálisis y Petroquímica ; Argentina Fil: Milt, Viviana Guadalupe. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Santa Fe. Instituto de Investigaciones en Catálisis y Petroquímica ; Argentina

This article is focused on the quality criteria of the measurement results from Turbo Charger Test Benches. The aim is to define clearly and precisely the quality criteria for the repeatability and reproducibility of the measurement results of turbo charger test benches, in order to give reliable measurement results for later use in engine process simulation and engine control unit calibration. The testing facility can be regarded as a complex measurement system. The results are affected by several parameters and boundary conditions. Some of them can be influenced by the test system itself; others are affected by the environmental conditions. An analysis of these phenomena is presented. In particular this paper discusses the conditions which can be influenced by the test bench (Measurement and Control) and defines a test procedure to verify the quality of the test results. References are made to the method of “Measurement System Analysis” as far as it is compatible to the complexity of turbo charger measurement.

Whine noise of main gearboxes is an important contributor to overall noise and acoustic discomfort in helicopters cabins. In order to better understand the industrial problematic, we first present our analysis concerning helicopters gearboxes noise. This status is based on simplified measurements performed in flight and on test bench. Then, we present our current hypothesis and developments concerning both integration and improvement of a methodology permitting to consider main gearboxes noise during helicopters design phases.

In this paper, a prognostic method is presented for fault detection in gears and bearings in wind turbine drivetrains. This method is based on angular velocity measurements from the gearbox input shaft and the output to the generator, using two additional angular velocity sensors on the intermediate shafts inside the gearbox. An angular velocity error function is defined and compared in the faulty and fault-free conditions in frequency domain. Faults can be detected from the change in the energy level of the frequency spectrum of an error function. The method is demonstrated by detecting bearing faults in three locations: the high-speed shaft stage, the planetary stage and the intermediate-speed shaft stage. Simulations of the faulty and fault-free cases are performed on a gearbox model implemented in multibody dynamic simulation software. The global loads on the gearbox are obtained from a dynamometer test bench and applied to the numerical gearbox model. The method is exemplified using a 750 kW wind turbine gearbox. The case study results show that defects in the high- and intermediate-speed bearings can be detected using this method. It is shown that this procedure is relatively simple, yet accurate enough for early fault detection in wind turbine gearboxes. Copyright © 2014 Elsevier Ltd. All rights reserved. This is the authors' accepted and refereed manuscript to the article.

Polymer gears replace metal ones in many motion and light power transmission applications. In order to improve the gears’ performance, glass fibre is added, where their lower cost and higher strength, offers a potential increase in the gears’ performance. This paper presents a numerical method to predict the mechanical and thermal behaviour of fibre reinforced plastic cylindrical gears and its experimental validation. The numerical method uses a viscoelastic model in its linear domain depending on temperature, humidity, rotational speed and fibre orientation. This numerical simulation computes the load sharing between instantaneously engaged gears and provides results such as contact pressure, tooth root stress or transmission error. The numerical results are then compared to experimental measures on a test bench developed at the LaMCoS laboratory. This comparison allows the validation of the load sharing model.

An Electrically Assisted Turbocharger (EAT) is one of the effective tools for improving transient response and fuel consumption. This paper describes the effects of an EAT mounted on a passenger car diesel engine (D/E) on fuel consumption during the New European Driving Cycle (NEDC) and on engine transient response, as predicted by means of engine simulation. The validity of the calculation model is confirmed by comparing simulation results against results of transient and steady tests conducted on an engine test bench.

A linear parameter-varying (LPV) model-based synthesis, tuning and assessment methodology is developed and applied for the design of a robust fault detection and diagnosis (FDD) system for several types of flight actuator faults such as jamming, runaway, oscillatory failure, or loss of efficiency. The robust fault detection is achieved by using a synthesis approach based on an accurate approximation of the nonlinear actuator–control surface dynamics via an LPV model and an optimal tuning of the free parameters of the FDD system using multi-objective optimization techniques. Real-time signal processing is employed for identification of different fault types. The assessment of the FDD system robustness has been performed using both standard Monte-Carlo methods as well as advanced worst-case search based optimization-driven robustness analysis. A supplementary industrial validation performed on the AIRBUS actuator test bench for the monitoring of jamming, confirmed the satisfactory performance of the FDD system in a true industrial setting.

In this paper, an experimental verification of the control of a modular series connected voltage source converter suitable for an HVDC transformerless offshore wind turbine is presented. The test bench is built around a 45 kW special generator prototype with three stator segments. Three 20 kW voltage source converter modules were used in the series connected converter. The experimental results verified the feasibility of a modular, decoupled control system design approach which has earlier been investigated through simulations. In addition, the experimental results are compared to simulations to verify the model implemented in EMTDC/PSCAD. © 2013 The Authors. Published by Elsevier Ltd. Open access under CC BY-NC-ND license (https://creativecommons.org/licenses/by-nc-nd/3.0/)

In this chapter, quite a broad overview of noise characterization-related topics is offered to the reader, with different depth levels. Most of the attention, however, is paid to the practical side of noise measurements and the subsequent steps of noise extraction and modeling, as well as to some advanced design methodologies. A major concern is in the procedures that are necessary to effectively de-embed the measurements from the contribution of the test bench and the adopted methodologies. The scope of the discussion cover a well-assessed theory concerning linear devices operated in the frequency range from a few megahertz to some 100 GHz, and at physical temperatures above some tens of kelvins. In these conditions, 1/f noise can be neglected and Johnson (thermal) noise is approximately independent of frequency; as a consequence, thermal and, possibly, shot noise of elemental noise sources add up to yield a white power spectrum, which can be conveniently described in terms of “equivalent” thermal noise. The second part of the chapter is devoted to the application of the device noise models in the proper design of single- and multistage low noise amplifiers, including a mixed technique that actually employs characterization techniques directly in the amplifier design.

This study presents a mathematical programming formulation for the design of water and heat exchangers networks based on a two-step methodology. First, an MILP (mixed integer linear programming) procedure is used to solve the water and energy allocation problem regarding several objectives. The first step of the design method involves four criteria to be taken into account., ie, fresh water consumption (F1), energy consumption (F2), interconnection number (F3) and number of heat exchangers (F4). The multiobjective optimization Min [F1, F2] is solved by the so-called ɛ-constraint method and leads to several Pareto fronts for fixed numbers of connections and heat exchangers. The second step consists in improving the best results of the first phase with energy integration into the water network. This stage is solved by an MINLP procedure in order to minimize an objective cost function. Two examples reported in the dedicated literature serve as test bench cases to apply the proposed two-step approach. The results show that the simultaneous consideration of the abovementioned objectives is more realistic than the only minimization of fresh water consumption. Indeed, the optimal network does not necessarily correspond to the structure that reaches the fresh water target. For a real paper mill plant, energy consumption decreases of almost 20% as compared with previous studies.

Publisher Summary From version 16.5, one can use the Partial Design Feature, which uses test benches to allow users to define those components that are used only for simulations. Users can also selectively partition designs for different simulation profiles and build up designs using circuits from other projects. Using test benches is very useful when users have a design that has been put together from a collection of circuits from other projects, as it will allow them to test the functionality of each individual circuit as they build up to the complete design. When a test bench is created, a Test Bench folder, which contains all the design schematics is added to the bottom of the Project Manager. All the components in all the schematics in the Test Bench folder are grayed out. Users then selectively “activate” those parts that are required for simulation and add parts such as voltage sources and load resistors. Parts can be deselected and selected either from the master design or from the created test benches. When users create a test bench, another design folder is created in the project folder. The Schematic-to-Schematic (SVS) utility compares test bench designs to the master design such that the master design can be updated with modified component values.

The aim of this work is to propose a black-box model to accurately predict the chilled water temperature dynamic response of a vapour compression chiller. The model is oriented to be of value in determining an adequate control algorithm based on compressor speed regulation. The model uses variables that are easily obtained in any commercial or industrial facility, such as the water inlet temperature and the compressor speed, to predict the chilled water outlet temperature. Several linear black-box model structures are proposed and their ability to describe the process behaviour is validated with experimental data from a monitored test bench. Finally, the Box–Jenkins structure shows the best fits, obtaining promising results.