Search

This paper deals with the numerical investigation of split hemispherical fins mounted staggered over a base plate. The thermal and flow analyses have been carried out to evaluate the Nusselt number (Nu), pressure drop Δ P , and hydrothermal performance factor (HTPF) with air as a medium and Reynolds number ( Re = / 3000 to 15000). The cylindrical fin (CF) and hemispherical fin (HF, of radius R ) of the same volume and height have been formed and placed in the computational domain. Results reveal that the Nu for CF compared to HF is 1.3-1.4 times higher, with approximately 1.5 times higher Δ P for the given Re range. The value of HTPF for HF is greater than unity (/1.13-1.20) for all the considered Re values. Secondly, the HF gets split into longitudinal and transverse flow directions for better solid-fluid interaction. The geometrical parameters are transverse offset TO (/= 0 − R / 8 ), longitudinal offset LO (/= 0 − R / 8 ), and Re. Results show that the highest value of Nu (/=384.10) and HTPF (/=1.33) have been obtained at TO = R / 10 (at LO =0) and TO = R / 10 (at LO = R / 10 ) for the highest Re (/=15000). At last, the cuckoo search algorithm (CSA) coupled with the response surface method (RSM) has been performed to fetch the optimum value of Nu based upon dimensionless TO ∗ , dimensionless LO ∗ , and Re. The optimum value (obtained at TO ∗ = 0.1 , L O ∗ = 0 , and Re = 15000 ) of Nu (=/392.16) from CSA is promising, with the numerically obtained Nu value (=/384.1059) with an error of 2.05%.

Lower alcohols have long been the figureheads of diesel/biodiesel additives in characterizing renewable fuels. Next-generation alcohol like n-octanol occupied the reified position due to their better fuel properties. In this paper, combustion, performance and, emission of different graphene-oxide nanoparticles (nanoGO) added jatropha biodiesel, n-octanol and petrodiesel blends are investigated in a 4-stroke DI diesel engine. This article also aims to optimize the engine inputs accountable for better performance and emission characteristics of a diesel engine running with nanoGO dispersed biodiesel/diesel/higher alcohol blends. Full Factorial Design-based Response Surface Methodology (RSM) is utilized to model the experiments using Design-Expert software to optimize engine responses. Validation of the developed model is carried out using sophisticated error and performance metrics, namely, TheilU2, Kling-Gupta Efficiency (K-G Eff), and Nash-Sutcliffe coefficient of efficiency (N-S Eff) along with the conventional statistical database. The model optimized engine inputs of 3.898% n-Octanol, and 49.772 ppm nanoGO at 99.2% load with a desirability index of 0.997 as the optimum engine parameters. The experimental validation revealed that the model optimized blend at full load witnessed a reduction of 15.6% CO, 21.78% HC.u, and 3.26% NOx emission compared to petrodiesel. However, a slight increase in brake specific energy consumption (2.95%) is also recorded because of the lower heating value of the blend.

The trade-off between performance and emissions must be in proper balance with the mineral fuels in executing a novel idea of renewable fuel design for existing and future combustors. Highe...

This paper deals with the thermal and fluid flow behavior of porous and non-porous fins. Initially, a solid heat sink with circular fins is analyzed and validated. Further work is done making circular tapered porous fin of the same volume and height as of uniform circular fin. The geometrical parameters are porosity (Ø = 0.1–0.92), pore diameter ( dp), fiber diameter ( df), radius ratio ( R*), and pores per inch (PPI = 10). Four different cases viz., case I ( R* = 1.2), case II ( R* = 1.5), case III ( R* = 2), and case IV ( R* = 4) of taper porous fins are considered in a computational domain with Reynolds number ( Re) ranging 400–1900 (based upon channel inlet parameter) and air as working fluid. The Forchheimer–Brinkman extended Darcy model is considered to characterize the flow in porous media. The value of Nusselt number ( Nu), friction factor ( f), and thermal performance factor (TPF) is evaluated. Results reveal that, for case I at Ø = 0.92 and PPI = 10, the value of Nu and TPF is approximately 63% and 159% higher than solid circular fin at Re = 1876.11. For case IV, the reduction in pressure drop is approximately 21.15% compared to solid circular fin at Re = 1876.11. For optimum Nu, a cuckoo search optimization is evaluated using the response surface method. Upon examination, the optimum Nu is obtained at the combination of R* = 1.2, Ø = 0.92, and Re = 1876.11, which got validated against the numerical work with 0.15% accuracy.

The issue of environmental pollution and the depletion of fossil fuel are nowadays a major field of attention for the modern world. In substitution of petroleum-based diesel, biodiesel and ethanol have been explored in many studies. In this paper, diesel-palm biodiesel-ethanol has been used together at different proportion to execute performanceemission characteristics and their trade-off study at different brake power. An experimental investigation is carried out for different diesel-palm biodiesel-ethanol blends ranging by volume of 5-10% ethanol, 5-25% biodiesel and 65-90% baseline diesel. From the experimental results, comparatively, low brake specific fuel consumption (BSEC) has been observed for all 5% ethanol-blended fuels. Maximum reduction in BSEC has been observed 1.9, 2, and 3.24 % at 0.68, 2.05, and 3.42 kW respectively. At medium to high load, brake thermal efficiency (BTE) has been found higher for lower ethanol fraction. As compared to diesel, the highest nitrogen oxide (NOx) reduction have been found 13.7, 9.17, and 4.7 % at 0.68, 2.05, and 3.42 kW respectively. At last, performance-emission trade-off shows that D70B25E5 blend has a higher BTE with maximum reduction in unburnt hydrocarbon (UHC) and NOx emissions.

With the prevalent interest in diesel engine performance and emission, it is necessary to define optimum engine operating condition with less number of experiments for the efficient and eff...

The present investigation delivers a comprehensive viewpoint on the current artificial intelligence (AI) meta-modelling in diesel engine system, particularly in the domains of multi-objective optimization. The relevance to the benefits of AI built modelling stratagems, and the probable Response Surface Methodology has been efficient with the consecutive growth in the current domains of the compression ignition technology. The study establishes the fundamental significance of inspecting certain multi-objective optimization stratagems matching with the accumulating need to deal with emission-performance trade-off trials of the compression ignition technology. To achieve the reliability and versatility of such model centered multi-objective optimization strategies, the current study delivers a unique case-study presenting the creditably accurate model-based standardization in an existing diesel engine. Therefore, n-Octanol produced in renewable ways, methyl esters of fish oil (MEFO) blended with diesel is used as fuel and the experiments were designed by Design of Experiments (DoE) based on response surface methodology (RSM) architecture. The results depicted that the tailor-made fuels proved their ability in terms of both performance and emissions when compared to mineral diesel. The model is further tested on a statistical platform with some special error matrices like Mean Squared Relative Error, MSRE, and Nash–Sutcliffe Coefficient of Efficiency, NCE along with conventional model testing metrics like MSE, RMSE and R which proved that the proposed model is robust and efficient in predicting the input-output paradigm. The ranges of correlation coefficients R, R2 and NCE are 0.99786 - 0.999992, 0.99786-0.999992 and 0.9957 – 0.999984 respectively. And the ranges of the error metrics Theil U2 and MSRE are 0.004048 0.065246 and 6.07E-07 to 0.000158 respectively. Optimization of input parameters was performed using the desirability approach of the response surface methodology for better performance and lower NOx and CO emission at a desirability index of 0.986. Experimental validation suggested a blend of 20% MEFO and 10% n-Octanol with petrodiesel at full loads were found to be optimal values for the test engine.

This paper investigates the consequence of linseed methyl ester and diethyl ether on the performance and emissions of the existing single cylinder compression ignition engine. Here biodiesel is mix...

Proper dissipation of thermal energy has always been a need for desirable efficiency of a system. Extended surface aids in releasing the heat to the immediate surrounding by inducing an extra area. This particular work assesses thermal and fluid flow behavior of extended surfaces with circular and elliptic shaped cross section. Extended surfaces of unvaried cross section are mounted over a square plate arrayed in a staggered manner. With the aid of different thermofluidic parameters, the elliptic shaped pin fin is established to provide a higher thermal performance enhancement of nearly 15% over cylindrical pin fin at inlet flow velocity of 2.35 m/s. Further, for elevating the interaction between the surface of the fin and the fluid, elliptic fins are reoriented to form a split. In contrast to cylindrical shaped fin, modification using split shows better result with the highest heat transfer increment of nearly 25%. Further, in order to maximize Nusselt number (Nu), a single objective cuckoo search optimization analysis is done by adopting the response surface method. After analyzing the optimization, it is found that the maximum value of Nu is obtained at dimensionless transverse offset (TO*) = 0.125 and dimensionless longitudinal offset (LO*) = 0, which has been further validated with the numerical result within 0.97% accuracy. Further, for the cylindrical fin, the present simulations agree with the available empirical correlation within 6.22% accuracy.

This present investigation focuses on combustion-performance-emission characteristics of cerium oxide (CeO2) added palm biodiesel blends in a single cylinder diesel engine. Experiments are conducted in a natural aspirated single cylinder diesel engine at constant speed and varying load (low, medium and full). The experimental result reveals that the addition of CeO2 nanoparticles (50, 100, and 150 ppm) to palm biodiesel blends enhanced brake thermal efficiency (BTE) with reduction in brake specific energy consumption (BSEC) due to improved ignition characteristics of the modified blends. Maximum reduction of CO, HC and NOx emissions have been observed 50, 48.45, and 11.1% at full load respectively. Later on, friction and wear study has been conducted to investigate tribological behavior of cylinder liner-piston materials under lubrication (using contaminated lubricant). The whole friction and wear study has been performed on pin-on-disc tribometer at different speed (300, 400, and 500 rpm) and load (10, 30, and 50 N). The dilution of CeO2 added biodiesel blends with the lubricant resulted low coefficient of friction (COF) and specific wear rate. At varying speed of 300, 400, and 500 rpm: 6.07, 8.5, and 10.9%; and at varying load of 10, 30, and 50 N: 6.07, 10.96, and 11.77% lower average COF have been observed respectively for nanofuels contaminated lubricant compared to diesel contaminated lubricant. Similarly, 7.94, 30, & 28.06% and 7.94, 30.33, & 17.04% lower specific wear rate at varying speed and load have been observed respectively for nanofuels contaminated lubricant.

In order to meet the challenges of global energy insecurity and the increasing obligation of complying with the environmental legislation, a paradigm shift from the reliance of conventional fossil fuel resources in IC engine domains are being increasingly witnessed. Exhaustive research has been carried out with non-conventional and alternative fuels resources in the off-road and transportation sector to meet the challenges of exploring a potential alternative to conventional diesel fuel with the additional objective of meeting the ever increasing stridency of the emission mandates. Among various alternative fuels, hydrogen whose clean and green burning characteristics has proven to be viable, sustainable fuels in IC engine domains with the premium quoting as one of the significant low emission signature than conventional fuels. Biodiesel, on the other hand, presents itself as a ready-to-use sustainable alternative in diesel powertrains in the environment of its National agricultural and rural economic development potential. As hydrogen is deemed to increase NOx emission when it is used with biodiesel, ethanol (20% v/v) blend with biodiesel has been used as a viable NOx suppression measure owing to its superior miscibility in methyl ester in comparison to conventional diesel. To this end, single cylinder diesel engine has been made to operate in a dual fuel mode with hydrogen as the dual fuel and mahua methyl ester with ethanol in blend as pilot fuel. The present aims of the study are to choose the best suitable fuel combination among the alternatives, in relation to various attributes chosen especially with an eye to address the performance-emission trade-off potential of the dual fuel operation. The most appropriate duel fuel combination out of ten alternatives has been discerned through distinct multi-criteria decision making (MCDM) methodologies. Analytic Hierarchy Process (AHP) has been applied for finding the weightage of each criterion and ranks of the alternatives investigated have been calculated by using VIKOR and PROMETHEE II methods. The alternative which signified biodiesel under hydrogen enrichment, at hydrogen injection duration of 9000 µs at a constant engine speed of 1500 RPM, was discerned as the the most appropriate alternative fuel combination at 75% load since it has been ranked first by both the MCDM methods. At full load for PROMETHEE II it was alternative A4, and for VIKOR it was observed as alternative A3 which signified biodiesel under hydrogen enrichment at hydrogen injection duration of 7000 µs at 1500 RPM. Alternatively, A10 strategy which indicate biodiesel ethanol blend along with hydrogen enrichment at hydrogen injection duration of 13,000 µs at 1500 RPM was observed to be the least preferential amongst the alternative for both the MCDM methods, at both 75% and 100% loads. Since there was consistency in the ranking, in order to judge the performance of both the methods Spearman’s Rank Correlation Coefficient was calculated and was observed to be within acceptable levels lending an index of robustness of the optimal choices of the strategies advocated by the MCDM methodologies adopted in the present case study.

Environmental pollution as well as fast depleting fossil sources are key factors leading toward search for the alternative resources of energy. Unlike fossil fuels, biofuels are renewable source of energy. Biofuel is defined as any fuel whose vitality is obtained through a course of biological carbon change. Today, the use of biofuels has extended throughout the earth. Major producers include Asia, Europe and America and they consume too. Biodiesel is unpolluted burning alternative energy source from 100% renewable resources which can be termed as the fuel for the future. Many edible alternatives such as Palm oil, Sunflower, Soya Bean and, non-edible alternatives such as neem, canola, mahua, karanja, and jatropha are tested successfully with or without engine modifications. The results are encouraging. Biodiesel is a green fuel that can be mixed with petroleum diesel to produce biodiesel blends to run diesel machines. This action can reduce huge foreign exchange load on government, and helps in reducing harmful emissions. In the present study, Pongamia pinnata methyl ester with an oxygenative additive DEE is added with diesel. Further, with the help of artificial intelligence an attempt is made to find out the optimal blend. Artificial Neural Networks in MATLAB are used to serve the purpose. Furthermore, with the help of an ANN meta model an attempt is made to find out the optimal blend.

This present investigation focuses on prediction of engine responses of a single cylinder CI engine powered by bio-diesohol (diesel-palm biodiesel-ethanol) blends using RSM (response surface methodology) and ANN (artificial neural network) model. RSM combined with multi-level general full factorial design (FFD) is used for the prediction of brake thermal efficiency (BTE), brake specific fuel consumption (BSEC), and nitrogen oxides (NOx). The engine experimental data is trained in ANN model using Levenberg-Marquardt back propagation training algorithm with logistic-sigmoid activation function. Different statistical measures are calculated to quantify the errors and correlations of the predicted models. Comparatively lower prediction error and higher correlation have been observed from the ANN model compared to RSM. The range of overall mean square error (MSE) and correlation coefficient are found (0.0003–0.00059) & (0.99403–0.998) and (0.00019–0.00035) & (0.99943–0.99971) from RSM and ANN model respectively. The range of overall mean absolute percentage error (MAPE) from ANN model (3.13–4.55%) is found lower compared to RSM model (3.97–6.6%). Thereafter, RSM and ANN predicted responses are introduced in fuzzy logic system for the optimization of engine operating parameters. At 100% load, the D75B20E5 (75% diesel + 20% palm biodiesel + 5% ethanol) blend has been found best for the optimization of BTE, BSEC and NOx emission. Finally, after the confirmation test, it has been revealed that the performance of D75B20E5 blend is as comparable to diesel.

The growing concern over the dependency on fossil fuel has prompted the cost of energy supply to the high extent. Widespread application of fossil fuel in transportation and electricity generation has steadily declined the fossil fuel supply along with the provoked environmental pollution. Strict environmental concern, depletion and price hike of fossil fuel has driven scientific study for the search of alternative fuels. To address the difficulties of fossil fuel, alternative fuels could be a fruitful substitute for global emission reduction. Where biodiesel makes itself as one of the best available resources due to its vast applicability in diesel engine. Among other biodiesels, palm biodiesel has proved itself as a most dominating biofuel due to its highest contribution worldwide (35%), minimum price (660 USD/ton), maximum oil content (5000 kg oil/ha), and production yield (4.2 MT/ha). The worldwide palm oil market progressively growing and it is expected to reach a market value of US$92.84 billion in 2021. The aim of this paper is to address different aspects of palm biodiesel for the potential solution of future renewable fuel. This paper describes a detailed review on palm biodiesel as a notable alternative in respect to the economy, environment, and efficiency. A thorough production process, properties, advantages, disadvantages, and the global economy of palm biodiesel are discussed. This article also deals with the sustainability, social, and environmental impact of leading palm oil producers like Malaysia, Indonesia, and Thailand. In this article, diesel engine combustion using palm biodiesel and its effect on engine efficiency and environmental pollution (due to engine emissions) are also reviewed. The scope of the present study relies on the brief description of the development and challenges of palm biodiesel feedstock for the continuation in the coming future.

A Pareto-based multi-objective optimization approach has been proposed to design and obtain Pareto-optimal set of solutions for performance and emission characteristics of a single cylinder, four stroke diesel engine using hydrogen in dual fuel mode. Instead of defining a single optimal objective, the proposed method establishes the multi-objective model by taking two design objectives into account, which are minimizing load (%) and hydrogen flow rate. To address this optimization problem, we develop a two-stage evolutionary computation approach integrating an exclusive non-dominated sorting genetic algorithm (NSGA-II) and technique for order preference by similarity to ideal solution(TOPSIS). NSGA-II has been utilized to search for the candidate solutions in-terms of both objectives. The obtained results have been obtained as Pareto-front. Subsequently, the best compromise solution has been determined by the TOPSIS method from the Pareto-front according to the decision maker's preference. The design results shows that the proposed approach yields a remarkable reduction in the emission spectra with enhancement in performance of the engine under a single podium obtained by multi-objective optimization.

The ever-increasing demand for fossil fuels and environmental issues have been the major concerns over the past few decades to search for viable alternative fuels where hydrogen find its suitability to be a viable and promising alternative fuel option on existing IC engine platforms in bridging the contemporary gap to the long term fuel cell based power train roadmap. It's clean burning capability helps to meet the stringent emission norms. Complete substitution of diesel with hydrogen may not be expedient for the time being but the potential use of hydrogen in a diesel engine in dual fuel mode is possible. The study also investigates the use of Artificial Neural Network modeling for prediction of performance and emission characteristics such as BSEC, BTE, NOx, Soot (FSN), UHC, CO2 of the existing single cylinder four-stroke diesel engine with hydrogen in dual fuel mode. Levenberg–Marquardt back propagation training algorithm with logarithmic sigmoid and hyperbolic tangent sigmoid transfer function have resulted in the best model for prediction of performance and emissions characteristics which has been well supported by the trade-off analysis between NOx–Soot (FSN)–BSEC. Fuzzy based analysis has been incorporated into existing ANN model for optimal parameter design which suggests the modesty of the employed transfer function of the existing ANN model.

This paper investigates use of artificial neural network (ANN) model in prediction of brake specific energy consumption (BSEC), nitrogen oxides (NOx), unburnt hydrocarbon (UHC), and carbon dioxide (CO2) emissions of a single cylinder diesel engine operates with diesel-palm biodiesel-ethanol blends. The engine is run at different load form 20–100% and 1500 rpm constant speed. The fuel used in this present study are diesel and six different diesel-palm biodiesel-ethanol blends. The Levenberg-Marquardt back propagation training algorithm with logistic-sigmoid activation function results best prediction of performance and emission characteristics with accurate overall correlation coefficient (R) (0.99329–0.99875) and minimum mean square error (MSE) (0.000179082–0.000465809). The mean absolute percentage errors (MAPE) are observed to be in range of 2.32–4.54% with the acceptable margin of mean square relative error (MSRE). Furthermore, experimental and ANN predicted data are compared in fuzzy interface system (FIS) to find optimum engine operating parameters. Compared to other blends, at 20% load, D85BD10E5 blend exhibits the highest MPCI (multi performance characteristics index) values of 0.718 and 0.705 for experimental and ANN predicted data respectively. Robustness and reliability of the proposed techniques clearly explain the application of ANN and fuzzy logic system in the prediction and optimization of engine parameters.

The present world faces the crisis of fossil fuels as it will no longer sustain in the future, gives a knowledge to look on waste resources, where waste rice and neem seed are utilizable for the production of biofuels by the process of fermentation and transesterification. In this paper, the physiochemical properties of the produced biofuels are examined. The 5% rice wine alcohol is used as an additive with neem methyl ester-diesel blend to lower the viscosity and flash point for the better performance in the single cylinder compression ignition engine. Different blends as D90B5RW5, D85B10RW5, D75B20RW5, and D65B30RW5 are prepared and examined experimentally by varying the engine loads (0–100%) at constant engine speed (1500 rpm). Experimental results showed the reduction of carbon dioxide (CO2), carbon monoxide (CO), hydrocarbon (HC) and smoke opacity, however oxide of nitrogen (NOx) is found higher. In the performance, D75B20RW5 shows 8% higher brake thermal efficiency and 3.33% lower brake specific fuel consumption compared to diesel. While in the combustion the peak cylinder pressure and net heat release rate are seen to be higher for biodiesel blends with additive.

The hydrogen-diesel dual fuel combustion was investigated in direct injection (DI) diesel engine. The investigation presented in this paper preferred hydrogen as a long-term renewable and least polluting fuel among various alternative fuels for internal combustion (IC) engines. In the current study a diesel engine is made to run using hydrogen in dual fuel mode with diesel, where hydrogen is introduced into the intake manifold using an LPG-CNG injector and pilot diesel is injected using diesel injectors. The hydrogen energy contents of the total fuel were varied from 0%, 11%, 17%, 30% and 42% (the 0% hydrogen energy content represents neat diesel fuel), were experienced at (1500 ± 10) rpm of invariable engine speed and 5.2 kW of consistent indicated power. The test results showed the improvement in brake thermal efficiency (BTHE) of the engine, reduction in brake specific energy consumption (BSEC) with an increasing hydrogen energy fraction. Furthermore, indicated specific CO, CO 2 and smoke emissions decrease with an increasing percentage of hydrogen energy content. Conversely, indicated specific NOx emissions increases with increase in hydrogen content. In addition to that, it was also observed that there was a sharp increase in peak in-cylinder pressure and the peak heat release rate values with the increasing hydrogen rate.

The investigation carried out in this research work concerns the effect of the addition of H2 on performance and emission characteristics of a single cylinder, 4-stroke diesel engine. The tests were performed using diesel as a pilot fuel, with hydrogen addition at varying load condition using a Timed Manifold Injection (TMI) system has been developed using ECU (electronic control unit) with varying injection strategy to deliver hydrogen on to the intake manifold. The results showed a significant increase in BTE with appreciable decrease in BSEC of the engine when compared to conventional diesel-fueled operation. The emission of CO2 and NOx was found to increase with enhancement of H2 addition. The emission of UHC was found to be very high at low load conditions, but it enhanced as the load increased for all hydrogen injection while Soot emissions decreased. Thus, this paper provided a potential to investigate the effect of the addition of H2 on the performance and emission characteristics of a diesel engine and how to get a best ratio of H2 addition. The tradeoff study also consolidated the verity that Diesel–H2 dual fuel operation was instrumental in resolving the high performance – low emission paradox.

Biodiesel with additives is generally preferred for improvement of performance and emission characteristics of diesel engines. Higher fuel injection pressure is effective in improving the performance and reducing emissions. In the present work, Isobutanol and ethanol as additives to the diesel-biodiesel blends was investigated experimentally in a direct injection diesel engine. Isobutanol (A1) and Ethanol (A2) were added 5%-10% by volume to diesel-biodiesel blends and the performance and emissions characteristics at different injection pressures viz. 200, 225, 250 and 275 bars were studied.From the results, it was found that nozzle opening injection pressure could be increased up to 250bar, as a result of which brake thermal efficiency and fuel economy of the engine were improved. Further, Carbon Monoxide (CO) emissions opacity was reduced significantly. However, Nitrogen Oxide (NOx) emissions decrease in some blends marginally.

The present energy situation and the concerns about global warming has stirred active research interest in non-conventional and alternative fuel resources to reduce the emission and the unabated fossil fuel dependency footprint, particularly for transportation, power generation and agricultural sectors. Among various alternatives, hydrogen has been extensively studied and concluded to be a viable and promising alternative fuel option on existing IC engine platforms in bridging the contemporary gap to the long term fuel cell based power train roadmap. Further, with the advent of EPA Tier 4 interim and final emission mandates the limits of the regulated emissions are challenging the practical limits of current engine design and calibration strategies. With a compliance directive of a substantial reduction in Soot and NOx emission levels simultaneously than its immediately preceding directives, engine manufacturers are being increasingly challenged to meet the paradox of curtailing particulate matter and NOx emissions on one hand and maintaining consumer expectations of increased thermal efficiency on the other. In this respect, various studies on the application of hydrogen as a dual fuel in existing IC engines offer the motivation to explore the potential in exploiting the inherent superior combustion characteristics of hydrogen as an in situ solution to the emission and performance trade-off challenges of conventional diesel combustion. In the present study, an experimental investigation was carried out existing CI engine with hydrogen as a dual fuel. A Timed Manifold Injection (TMI) system was adopted to analyze the effect of durations of hydrogen induced on the performance and emission characteristics as compared to baseline diesel operation. Previous studies have already clearly established the virtues of hydrogen in mitigating the emission footprint of conventional diesel operation along with improved performance characteristics. However, with the penalty of increased NOx emissions with hydrogen participation, a definite study specifically addressing the NOx-Soot-BTHE trade-off vantage achievable on existing CI engines under the purview of existing emission mandates is yet to be addressed. Based on an experimental investigation, the present study employs offline calibration techniques centered on the rationale of the fuzzy logic based Taguchi analysis to investigate the optimal soot-NOx-BTHE trade-off regime of operation based on different hydrogen injection strategies.

The present experimental investigation attempts to explore the performance characteristics of an existing single-cylinder four-stroke compression-ignition engine operated in dual-fuel mode with hydrogen as an alternative fuel. Experimental investigation was conceded with the engine being subjected to different loads at a predefined flow rate of hydrogen induction. A Timed Manifold Injection (TMI) system has been developed to vary the injection timing and the durations. The optimized timing for the injection of hydrogen was 100 CA after top dead center (ATDC). From the study it was observed that hydrogen with diesel results in increased brake thermal efficiency (BTHE) by 15.7% at 40% full load, volumetric efficiency (Vol. Eff.) by 78.5% at full load condition compared to baseline diesel operation. Hydrogen enrichment registered a maximum reduction of 41.4% in specific fuel consumption (SFC) of diesel at 20% full load. A pareto-optimal front was then obtained using nondominated sorting genetic algorithm (NSGA). Analysis of the front was done to identify the separate regions for Brake specific energy consumption (BSEC), Brake thermal efficiency (BTHE) and Volumetric efficiency (Vol. Eff.). Designed experiments were then conducted in these focused regions to verify the optimization results and to identify the region– specific characteristics of the process.

Environmental issues and rapid exhaustion of fossil fuels are the major concerns over the past two decades to search for alternative fuels. Among various alternatives hydrogen is a long-term renewable and least polluting fuel. Its clean burning capability helps to meet the stern emission norms. Full substitution of diesel with hydrogen may not be convenient for the time being but employing of hydrogen in a diesel engine in dual fuel mode is possible. In this experimental investigation a TMI (timed manifold injection) system has been developed using ECU (electronic control unit) with varying injection strategy to deliver hydrogen on to the intake manifold. Through adopting this technique in the existing diesel engine a momentous improvement in performance and combustion parameters has been observed. The study also attempts to explain the application of the fuzzy logic based Taguchi analysis to optimize the performance parameters i.e. BSEC (Brake specific energy consumption), Vol. Eff. (Volumetric efficiency) and BTHE (brake thermal efficiency) for the different hydrogen injection strategies.

The present work attempts to investigate the combustion, performance and emission characteristics of an existing single-cylinder four-stroke compression-ignition engine operated in dual-fuel mode with hydrogen as an alternative fuel. Environmental concerns and limited amount of petroleum fuels have caused interests in the development of alternative fuels like hydrogen for internal combustion (IC) engines. In this experimental investigation, a diesel engine is made to run using hydrogen in dual fuel mode with diesel, where hydrogen is introduced into the intake manifold using an LPGCNG injector and pilot diesel is injected using diesel injectors. A Timed Manifold Injection (TMI) system has been developed to vary the injection strategies. The optimized timing for the injection of hydrogen was 10^0 CA after top dead center (ATDC). From the study it was observed that with increasing hydrogen rate, enhancement in brake thermal efficiency (BTHE) of the engine has been observed with reduction in brake specific energy consumption (BSEC). Furthermore, Soot contents decrease with an increase in indicated specific NOx emissions with the enhancement of hydrogen flow rate., {"references":["J.M. Gomes Antunes, R. Mikalsen, A.P. Roskilly, An experimental\nstudy of a direct injection compression ignition hydrogen engine,\nInternational Journal of Hydrogen Energy, Volume 34, Issue 15, August\n2009, Pages 6516-6522, ISSN 0360-3199,\nhttp://dx.doi.org/10.1016/j.ijhydene.2009.05.142.","Biplab K. Debnath, Ujjwal K. Saha, Niranjan Sahoo. Effect of\nhydrogen-diesel quantity variation on brake thermal efficiency of a dual\nfuelled diesel engine. Journal of Power Technologies 92 (1) (2012) 55-\n67.","N. Saravanan, G. Nagarajan, Performance and emission studies on port\ninjection of hydrogen with varied flow rates with Diesel as an ignition\nsource, Applied Energy, Volume 87, Issue 7, July 2010, Pages 2218-\n2229, ISSN 0306-2619,\nhttp://dx.doi.org/10.1016/j.apenergy.2010.01.014.","Heffel James W, Mcclanahan Michael N, Norbeck Joseph M. Electronic\nfuel injection for hydrogen fueled internal combustion engines. SAE\nTransactions 1998. 981924.","G.P. Prabhukumar, S. Swaminathan, B. Nagalingam, K.V.\nGopalakrishnan, Water induction studies in a hydrogen-diesel dual-fuel\nengine, International Journal of Hydrogen Energy, Volume 12, Issue 3,\n1987, Pages 177-186, ISSN 0360-3199, http://dx.doi.org/10.1016/0360-\n3199(87)90151-0.","Y. J. Qian, C. J. Zuo, J. T. H. M. Xu, Effect of intake hydrogen addition\non performance andemission characteristics of a diesel engine with\nexhaust gas recirculation, proceedings of the institution of mechanical\nengineers, Journal of Mechanical Engineering Science 225 (2011) 1919-\n1925.http://dx.doi.org/10.1177/0954406211403663","L.M Das, Near-term introduction of hydrogen engines for automotive\nand agricultural application, International Journal of Hydrogen Energy,\nVolume 27, Issue 5, May 2002, Pages 479-487, ISSN 0360-3199,\nhttp://dx.doi.org/10.1016/S0360-3199(01)00163-X.","N. Saravanan, G. Nagarajan, C. Dhanasekaran, K.M. Kalaiselvan,\nExperimental investigation of hydrogen port fuel injection in DI diesel\nengine, International Journal of Hydrogen Energy, Volume 32, Issue 16,\nNovember 2007, Pages 4071-4080, ISSN 0360-3199,\nhttp://dx.doi.org/10.1016/j.ijhydene.2007.03.036.","Madhujit Deb, Rahul Banerjee, Arindam Majumder, G.R.K. Sastry,\nMulti objective optimization of performance parameters of a single\ncylinder diesel engine with hydrogen as a dual fuel using pareto-based\ngenetic algorithm, International Journal of Hydrogen Energy, Volume\n39, Issue 15, 15 May 2014, Pages 8063-8077, ISSN 0360-3199,\nhttp://dx.doi.org/10.1016/j.ijhydene.2014.03.045.\n[10] P. K. Bose, R. Banerjee, An Experimental Investigation on the Role of\nHydrogen in the Emission Reduction and Performance Trade-Off\nStudies in an Existing Diesel Engine Operating in Dual Fuel Mode\nUnder Exhaust Gas Recirculation, Journal of Energy Resources\nTechnology(ASME), March 2012, Vol. 134 / 012601-15.\nhttp://dx.doi.org/10.1115/1.4005246\n[11] IS 10,000(Part 8):1980 (Reaffirmed Aug 2010; Amendments: 1):\nMethods of tests for internal combustion engines: Part 8 Performance\ntests, Retrieved from: http://www.bis.org.in/sf/pow/ted.pdf- on August,\n2010 [12] IS 10,000(Part 6):1980 (Reaffirmed Aug 2010; Amendments:\n1):Methods of tests for internal combustion engines: Part 6 Recording of\ntest results, Retrieved from: http://www.bis.org.in/sf/pow/ted.pdf- on\nAugust, 2010\n[13] Lilik, G, 2007, \"Mixing Length of Hydrogen in an Air Intake\",\nRetrievedfrom:http://www.ems.psu.edu/~elsworth/courses/EGEE520/20\n07Deliverables/Reports/Greg_Lilik_Final_EGEE_520v6.pdf - on 20th\nJuly, 2011."]}

The present energy situation and the concerns about global warming has stimulated active research interest in non-petroleum, carbon free compounds and non-polluting fuels, particularly for transportation, power generation, and agricultural sectors. Environmental concerns and limited amount of petroleum fuels have caused interests in the development of alternative fuels for internal combustion (IC) engines. The petroleum crude reserves however, are declining and consumption of transport fuels particularly in the developing countries is increasing at high rates. Severe shortage of liquid fuels derived from petroleum may be faced in the second half of this century. Recently more and more stringent environmental regulations being enacted in the USA and Europe have led to the research and development activities on clean alternative fuels. Among the gaseous fuels hydrogen is considered to be one of the clean alternative fuel. Hydrogen is an interesting candidate for future internal combustion engine based power trains. In this experimental investigation, the performance and combustion analysis were carried out on a direct injection (DI) diesel engine using hydrogen with diesel following the TMI(Time Manifold Injection) technique at different injection timings of 10 degree,45 degree and 80 degree ATDC using an electronic control unit (ECU) and injection durations were controlled. Further, the tests have been carried out at a constant speed of 1500rpm at different load conditions and it can be observed that brake thermal efficiency increases with increase in load conditions with a maximum gain of 15% at full load conditions during all injection strategies of hydrogen. It was also observed that with the increase in hydrogen energy share BSEC started reducing and it reduced to a maximum of 9% as compared to baseline diesel at 10deg ATDC injection during maximum injection proving the exceptional combustion properties of hydrogen., {"references":["L.M. Das ( Hydrogen Engine; Research and development Programs in\nIndian Institute of Technology ), International Journal of Hydrogen\nEnergy, Vol.27, No.9, PP.953-965, 2002.","Polasek Milos, Macek Jan and Takats Michal ( Hydrogen Fueled Engine\nProperties of Working Cycle and Emission Potentials ), SAE Paper\nNo.020373, 2002.","Mihaylov Milen and Barzev Kiril,( Investigation of The Effects of\nHydrogen Addition on Performance and Exhaust Emissions of Diesel\nEngine ) ,FISITA World Automotive Congress,23-27 May ,2004\nBarcelona ,Spain .","S.J. Lee , Yi HS and E.S. Kim , ( Combustion Characteristics of Intake\nPort Injection Type Hydrogen Fueled Engine ), International Journal of\nHydrogen Energy Vol.20,No.2,pp.317-322,1995.","Barreto L, Makihira A, Riahi K. The hydrogen economy in the 21st\ncentury: a sustainable development scenario. IJHE 2003;28:267-84..","Kukkonen Carl A, Shelef Mordecai. Hydrogen as an alternative\nautomotive fuel. SAE transactions 1994. 940766.","Das L.M. Near-term introduction of hydrogen engines for automotive\nand agriculture application. IJHE 2002;27:479-87.","Das LM. Hydrogen engine: research and development (R & D)\nprogrammes in Indian Institute of Technology (IIT), Delhi. IJHE\n2002;27:953-65.","Guo LS, Lu HB, Li JD. A hydrogen injection system with solenoid\nvalves for a four cylinder hydrogen fuelled engine. IJHE 1999;24:377-\n82. No. 9, p. 723-6.\n[10] Lee JT, Kim YY, Lee CW, Caton JA. An investigation of a cause of\nbackfire and its control due to crevice volumes in a hydrogen fueled\nengine, vol. 123. ASME; 2001.\n[11] Massod M, Ishrat MM, Reddy. Computational combustion and emission\nanalysis of hydrogen-diesel blends with experimental verification. IJHE\n2007;32:2539-47.\n[12] Lee Jong T, Kim YY, Caton Jerald A. The development of a dual\ninjection hydrogen fueled engine with high power and high efficiency.\nIn: 2002 Fall technical conference of ASME-ICED, 8-11 September,\n2002. p. 2-12.\n[13] Das LM. Hydrogen engine: research and development (R&D)\nprogrammes in Indian Institute of Technology (IIT), Delhi. IJHE\n2002;27:953-65.G. R. Faulhaber, \"Design of service systems with\npriority reservation,\" in Conf. Rec. 1995 IEEE Int. Conf.\nCommunications, pp. 3-8.\n[14] A.P. Roskilly, J.M. Gomes Antunes, R. Mikalsen, \"An investigation of\nhydrogen-fuelled HCCI engine performance and operation\".\nInternational Journal of Hydrogen Energy 2008;33: 5823-28.\n[15] J. D. Naber, D. L. Siebers, S. S. Di Julio, C. K. Westbrook, \" Effects of\nnatural gas composition on ignition delay under diesel conditions,\"\n,Combustion and Flame, Volume 99, Issue 2, November 1994, Pages\n192-200.\n[16] Heffel James W, Mcclanahan Michael N, Norbeck Joseph M. Electronic\nfuel injection for hydrogen fueled internal combustion engines. SAE\nTransactions 1998. 981924.\n[17] Yamin Jehad AA, Gupta HN, Bansal BB, Srivastava ON Effect of\ncombustion duration on the performance and emission characteristics of\na spark ignition engine using hydrogen as a fuel. IJHE 2000;25:581-9.\n[18] Ma Jie, Su Yongkang, Zhou Yucheng, Zhang Zhongil. Simulation and\nprediction on the performance of a vehicle-s hydrogen engine. IJHE\n2003;28:77-83.\n[19] Lee JT, Kim YY.The development of a dual injection hydrogen fueled\nengine with high power and high efficiency. In: Fall technical\nconference of ASME-ICED, 8-11 September 2002; 2002.\n[20] Norbeck Joseph M, Heffel James W, Durbin Thomas D, Tabbara\nBassam,Bowden John M, Montano Michelle C. Hydrogen fuel for\nsurface transportation.SAE order No. R-160. SAE, ISBN 1-56091-684-\n2; 1996.\n[21] Lee SJ, Yi HS, Kim ES. Combustion characteristics of intake port\ninjection type"]}