Search

Heat is a form of energy and it changes from one form to another form and nature of heat is flowing from higher temperature to lesser temperature. Generally weuse finsfor decreasing the temperature of the body. Fins which are extendedsurfaces andused for increasing heat transfer rate from the body when we don't have any other option to increase heat transfer coefficient and temperature difference. These extended surfaces are used in various profiles in many industrial applications like auto vehicles, aircrafts, air conditioning devices, electric equipment and other large number of industries. One such profile is a triangular profile of fins which are mostly used in aircraft applications because of their less quantity of material requirement for high heat transfer rate. Various fin profiles such as pin, circular, rectangular, triangular, trapezoidal, concave parabolic and convex parabolic fins have been analyzed by several researchers. Use of fins in automobile applications is also analyzed by various researchers.The engine cylinder which is one of the most important components in the field of automobiles applicationsis subjected to high temperature variations and thermal stresses. We can use fins on the surface of the engine cylinder for cooling of these engine cylinders to increase the heat transfer rate by convection mode. In this review paper we will review various researches done in the field of heat transfer using fins for various applications for maximum heat transfer rate. [ABSTRACT FROM AUTHOR]

The problem of developing alternative energy sources with high efficiency was posed back in the middle of the 20th century. One of the possible ways to solve it is the development of systems based on direct absorption solar collectors based on nanofluids. Systems of this kind are the most environmentally friendly and modern, the disadvantages of which include the complexity of maintenance and climatic restrictions of widespread use. The aim of this paper is to determine ways to increase the efficiency of heat transfer in systems for collecting and storing solar energy by means of mathematical modeling of heat and mass transfer processes in direct absorption solar collectors based on nanofluids. When constructing a mathematical model, the contributions of the diffusion and electrostrictive components were taken into account. A mathematical model of heat and mass transfer in a liquid-phase medium with nanoparticles under the action of a light field is investigated, taking into account one-dimensional concentration convection in the form of a boundary-value problem for a system of second-order partial differential equations. The reported study was funded by RFBR, project number 19-31-90070. [ABSTRACT FROM AUTHOR]

The paper is focused at the phenomenon of heat transport at high temperature and aimes at determination of heat transfer coefficient in particular. The presented research is based on the combination of experimental and computational approach that creates a perfect combination for application of the inverse analysis methods. In this paper, the inverse analysis is conducted by means of genetic algorithm allowing for the identification of heat transfer coefficient as a function of temperature. The results of such an application showed high dependancy of the studied parameter on temperature, especially when temperatures above 500 °C are considered. The outcome of this research underlines the necessity of seeking for the solution in the form of temperature-dependent functions to provide complex and accurate analysis of heat transfer at high temperatures. [ABSTRACT FROM AUTHOR]

Pipes in heat exchanger systems are usually made of metallic materials to achieve a high level of thermal conductivity and thus high efficiency. However, substitution with polymer materials has a great potential. Plastics save weight, can be produced at lower cost and emissions, and are ideal for use in corrosive or chemically aggressive environments, where most metals fail. The challenge, however, is their much lower thermal conductivity in comparison. To reduce this disadvantage, fillers are used to transport thermal energy through the less conductive polymer matrix. In fact, high filler ratios are required to achieve an acceptable level of thermal conductivity for heat exchanger systems. However, these high filler ratios have a significant impact on the material properties of the polymer, such as the flexibility, which is drastically reduced. The result is a brittle material with limited suitability for use in heat exchanger systems. This paper describes a novel approach to effectively increase the thermal conductivity of polymer materials by optimizing the orientation of anisotropic filler particles by die design. Standard pipe extrusion dies result in continuous shear forces in the direction of extrusion. Accordingly, the resulting filler network has a higher thermal conductivity in the axial direction of the pipe than radially through the pipe wall. However, radial heat transfer is essential in pipe heat exchanger systems. To improve this, various die designs for targeted radial alignment of filler particles are discussed in this paper. Furthermore, the potential for improvement of the die designs is investigated. So far, the most efficient die design achieves an increase in thermal conductivity of up to 74 % compared to a standard pipe extrusion die. [ABSTRACT FROM AUTHOR]

In this paper research has been conducted by varying the internal design of the pipes that are used in the compact air to air heat exchanger to see if the addition of turbulizers in the internal section can result in an improvement in the ΔT at the exit of the pipe. We are also looking at the internal flow characteristics of the air inside the heat exchanger pipes. The drop in pressure at the exit of the pipes because of the addition of the turbulizers has also been investigated. All these analysis have been performed using the commercial software package ANSYS CFX and the results are presented in this paper. [ABSTRACT FROM AUTHOR]

Taking advantage of the potential of daylighting in the building helps to save energy used for artificial lighting. In Russia and other countries, where most of the energy is consumed for heating in winter, the increased window area leads to a reduction in the energy costs of artificial lighting but increases the heat loss through the windows blocks. Some studies contain criteria for assessing the feasibility of increasing the area of window, however, the influence of artificial light sources have not included. In this paper, the thermal balance of the room is considered, including the influence of artificial light sources, heat gain from solar radiation and transmission heat loss through window blocks. By calculating the difference in the thermal balance of the room after and before the increase in the window area, an expression of the criterion for evaluating the benefits of increasing the window area by energy indicators was obtained. Based on the cost of heat and electricity, the expression of the criterion for assessing the benefits of economic indicators was proposed. According to the presented criteria, the calculation for different function spaces: residential, office and school classes designed for Moscow was carried out. It is shown that, according to energy indicators, an increase in the window area is unprofitable or low profitable for residential and office premises, but beneficial for the school class. In conclusion, the paper shows the possibility of evaluating the energy efficiency of increasing the area of the window using the developed criteria. [ABSTRACT FROM AUTHOR]

This paper describes the results of the development and testing of the methodology for modeling multiphase flows of various types, given the heat exchange with the environment in the OpenFOAM open package, with it compressibleInterFoam solver. The solver uses the Volume of fluid (VOF) method to trace the interface between the liquid and gas phases of the flow Verification of developed method was held on experimental data for different Reynolds numbers and flow structures (split-wave, slug flow, annular flow). The algorithm for calculating the physicochemical parameters of the multiphase mixture is shown. The developed numerical approach is shown to correctly determine the multiphase flow structures in the pipeline, as well as to determine the temperature fluctuations arising in the pipeline, which is an important parameter when calculating the durability of the pipeline during its operation. [ABSTRACT FROM AUTHOR]

A solar air heater is a system that transforms solar power into a form that may be used for a variety of heating applications. Researchers are experimenting to increase the heat transfer by breaking down the laminar sub-layer near the adsorbing plate. To break the laminar sub layer, researchers have applied varieties of roughness with different shapes and sizes. The experimentation with varieties of roughness leads to an increase in cost as well as effort. So, the development of high-end computational software can minimize this. Computational fluid dynamics has emerged as a very efficient tool to perform the analysis with less cost and effort. The paper aims to give a comprehensive review of CFD analysis that has been used by various researchers to evaluate the thermo-hydraulic performance of artificially roughened solar air heaters. This paper represents the brief details of the CDF model, CFD domain, different roughness, and system and operating parameters to achieve the optimal thermal performance of solar air heaters. [ABSTRACT FROM AUTHOR]

This paper aims to improve the thermal performance of Closed loop pulsating heat pipe (CLPHP) with nanofluid fused with refrigerants. In this paper, the thermal studies were carried out by SWCNT and MWCNT nanofluids fused with R-134a. Experimentation was conducted at 10W heating power and 90° inclination angle, temperature difference from evaporator and condenser were validated. Results indicate that using nanofluid fused with R-134a, could improve the thermal performance of heat pipes. And the readings were taken every two minutes. And the obtained result was plotted to and the result shows the addition of CNT nanofluid to the refrigerant improves the Thermal performance of the closed-loop heat pipe (CLPHP). Compare to SWCNT, MWCNT with R-134a shows better heat transfer and improve the cooling capacity. [ABSTRACT FROM AUTHOR]

In this paper investigation numerically varies shape perforated area on enhancement in heat transfer was investigated along two-pass ribbed channel with internally of two-phase flow. Ribs have a curved shape with two cases. In this paper investigation numerically the effects of shape perforated area on enhancement in heat transfer was investigated along two-pass ribbed channel with internally of two-phase flow. Ribs have a curved shape with two cams with perforated same areas with various shapes; triangle, square, circle areas and comparison with solid case. The study performed at same conditions for all cases, of water & air velocities are (0.1684m/s) & (2.193m/s), respectively. Numerical simulation by ANSYS FLUENT 2021 R1 employed to study the heat transfer enhancement. The results showed that the circle area have high turbulence to increase enhancing in heat transfer coefficients in compared with other cases. However, the pressure decreased with ratio of passing from inlet to outlet ribbed region through bend region (S) to Hydraulic diameter (D) in ribbed region but in bend region a sharply in triangle and square cases decreased in pressure lead to increase pressure drop and increased losses. The percentage of enhancing heat convective was around (25% in case of square perforated area, 29% in triangle perforated area, 35% in circle perforated area) in comparison with solid curved ribs. [ABSTRACT FROM AUTHOR]

Through means of this specific paper, we have likely embraced an investigation towards leading an examination in regards to "flow and heat transfer qualities in a second grade liquid through a permeable medium over a straight extending surface with two general cases, in particular PST and PHF, including the impact of viscous dissipation". Subsequently, fractional differential conditions administering the idea of "flow and heat movement are changed over into non-linear customary differential conditions and limit conditions by utilizing suit-capable similitude change", was regularly being thought of. Accordingly, the proposed issue identifying with our paper, was fundamentally being addressed systematically, by methods for power arrangement strategy, wherein subsequently graphical outcomes for "speed, skin-grinding coefficient, and temperature for PST and PHF cases are also introduced and talked about, close by thought of mathematical qualities identifying with divider grating coefficient, divider temperature slope θη (0), and divider temperature θ (0)" were in like manner being determined, organized, & examined subsequently. [ABSTRACT FROM AUTHOR]

The paper analyses the impact of the use of brass meshes as the passive method of boiling heat transfer augmentation. The test results of water and ethanol boiling under ambient pressure indicate a significant improvement of heat transfer in comparison to the surface without the mesh. The phenomenon can be explained by an increased number of nucleation sites present on the heating surface if mesh layers are applied. [ABSTRACT FROM AUTHOR]

Since the 1990's, nanofluids have been one of the abundantly preferred newcomer technology invented to assist in electronic and heat transfer purposes. Their thermophysical properties and heat transfer performance make nanofluids highly demanded to overcome the current issues in the world. In this paper, a vast number of applications using nanofluids are reviewed as well as an epitome on the challenges in their respective areas. Additionally, recent research papers for specific applications of nanofluids in improving heat transfer efficiency were outlined while the experimental and theoretical methods were discussed in the articles and journals is summarized in this paper including the effects of thermal properties on the performance of nanofluids. In a nutshell, this review of experimental research extracted from most recent papers, published from 2011 to 2016, is a review on the latest updates in the nanofluids and heat transfer community to help anyone in concern of the topic and enough information to select nanofluids based on their needed applications. [ABSTRACT FROM AUTHOR]

Fins are the important component in an IC engine cylinder block which is responsible for heat removal during the combustion process via convection process. The efficient removal of heat transfer can always maintain the consistent efficiency of an IC engine. The fins are of different types which are generally used based on the heat transfer rate requirement. The main aim of the paper is to analyze the thermal properties by varying geometry and thickness of cylinder fins. To improve the rate of heat transfer thermal analysis of two designs providing slot, reducing the fin thickness and increasing no. of fins is carried out in this paper. The cylinder blocks with fins are modeled and analysis is done in CAD and FEA software. [ABSTRACT FROM AUTHOR]

In this paper, a calibration and validation of the newly formulated model for prediction of indoor air temperature is presented. The construction of the model is based on the interconnection between two independent models – first for calculation of heat transfer rate through opaque building envelope, the second for calculation of indoor temperature from user-defined building envelope parameters. The model introduces several simplifications and therefore the validation is essential to prove its capability of solving indoor air related problems. The calibration, which was done on series of data taken form in-situ measurement, allowed for model adjustment and subsequent validation. As the agreement between predicted and experimentally determined room temperature was less than 1 °C the model can be considered as being capable of solving tasks and problems in the field of building engineering. [ABSTRACT FROM AUTHOR]

Evaporative cooling has been around since ancient times. As a cooling device, evaporative cooling has several advantages and disadvantages. This paper discusses some of the results of investigations on three types of evaporative cooling, namely direct evaporative cooling, indirect evaporative cooling, and combined evaporative cooling. Cooling media is part of the evaporative cooling that is widely studied. Some researchers also made several innovations to improve the efficiency of evaporative cooling. One of the innovations that will be discussed in this paper is to add heat pipes to evaporative coolers. As a passive heat transfer, heat pipes are expected to increase the efficiency of evaporative cooling without adding high cost. [ABSTRACT FROM AUTHOR]

End-of-Life tires (EOLT) are ones of the most dangerous waste in the world. They do not practically decompose in nature. Because of this their sound treatment is needed for the environment protection. One of the possible methods for such a treatment is pyrolysis process. It is well known [3, 4] that globally around 23% of all EOLT are processed through pyrolysis, whereas in the Republic of Bulgaria only 5% are processed by this method. Thus for Bulgaria it becomes clear that the pyrolysis method for EOLT treatment still has a good potential for usage, development and further research. This method is very complicated for modeling and studying, because it is 3D and non-stationary. In our previous work [1] we created an adequate mathematical model and numerical algorithm in MATLAB for numerical solving the mathematical initial and boundary value problems for model equations which describe pyrolysis process used for the treatment of the End-of-Life tires (EOLT). Some results for the temperature field for several characteristic periods of operation of pyrolysis station are presented and commented in the papers [1, 2, 5]. This paper deals with studying the influence of two-burner heating upon the heat transfer during EOLT treatment by pyrolysis process. The results for temperature fields, temperature isolines and gradients at some specific moments of time and for two different initial heating functions are graphically presented and commented. Results from this modeling can be used in the real pyrolysis stations for more precise displacement of heathers and measurement devices and for designing of automated management of the process. [ABSTRACT FROM AUTHOR]

The electrical performance and reliability of Photovoltaic solar panel (PVSP) depends on the working temperature. The performance of the PVSP decreases with the temperature increase of the PVSP. The thermoelectric heat sink (THS) for cooling PVSP is investigated in this paper. Moreover, Four perforated geometries are numerically analyzed in the comparative analysis of the pin-fin heat sink used to cool the PVSP (original pin fin-heat sink model A, circle hole model B, square hole model C and triangle hole model D). This paper demonstrates the efficiency of the PVSP by increasing the cooling process to improve the effectiveness of the PVSP's overall electrical conversion. A numerical analysis was conducted to estimate how long it takes to cool the PVSP to its standard operating temperature, depending on the cooling selected. During the numerical simulation, different temperatures and air velocity conditions are taken into consideration. Air is used as a cooling fluid that flows at a low rate to achieve a laminar flow. The temperature of the PVSP decreased with perforated fins due to an improvement in the conventional heat transfer area. The increase in the number of fins in models B, C and D causes a decrease in the spacing between the pin fin-heat sink duo to lower the PVSP temperature. It is also concluded that the use of a pin-fin heat sink to cool the PVSP is an efficient and cost-effective technique to improve the efficiency of the PVSP. [ABSTRACT FROM AUTHOR]

The main problem with food delivery service is its long distance. The longer time for food delivery will affect the food's freshness. This paper contributes to utilizing heat energy from motorcycle exhaust for food warming containers. The exhaust energy maintains the temperature of the food delivery container using a heat exchanger concentrically attached to the exhaust pipe. The medium for heat transfer uses water which is closely circulated from the food container and heat exchanger. The analysis was carried out using fluent ANSYS with a kappa-epsilon turbulence model with variation velocity of the inlet flow (0.18 m.s−1, 0.36 m.s−1, 0.54 m.s−1, and 0.72 m.s−1). The initial temperature of the box was 300 K, and the inlet temperature of the box was 333 K. The computation results showed that the higher velocity of inlet flow affects the higher Reynold number. It indicates the greater turbulence of fluid inside the system. The greater turbulent flow enhances the heat transfer rate between the water and the walls of the box. [ABSTRACT FROM AUTHOR]

In this paper, we study the investigation of the properties of a nonhomogeneous double nonlinear heat transfer equation in various media with respect to density and source. It is proved that for a given equation, the parameter values exist and have a numerical solution. The system of equations considered in this paper is based on most physical processes, for example, the reaction-diffusion process in this system, thermal conductivity, polytrophic filtration of gas and liquid in nonlinear media is described by a source. There are a lot of partial solutions to this equation. One of the main methods of studying the problem under consideration is the construction of an integral self-model solution. To do this, initially, when constructing a system of self-similar equations, a nonlinear subtraction method was used. The following results were obtained from this work: the front for the equation of nonlinear heat generation with doubled energy was estimated, the localization process was observed, new effects were observed, an algorithm was constructed in accordance with the obtained self-similar solution, a program code was created in the programming language, and the process modeling was visualized. [ABSTRACT FROM AUTHOR]

Reaching the maximum level of the users' comfort in the building is an important role. At the same time, it is vital to have occurred minimum negative environmental effects. Having an atrium as a popular area in the building needs to investigate thermal performance. This paper finds out the effects of the floor heigh into the internal condition as the liner atrium with optimum shading device during the warm period. This paper illustrated the different results according to the atrium building height as floor numbers including 1, 3, and 5 floors in Famagusta, North Cyprus climate. As finding in all building height simulation models in August is the maximum discomfort condition month and maximum cooling loads as air-conditioning system, because of internal building gained and ventilation gains, (single floor Qz between 330 to-330 watts, Qv:-2000 to 2000 watts), (three floors Qz between 1200, 2200 watts to-1200,-2200 watts, Qv:-7000 to 7000 watts), and (five floors Qz between 2000, 4500 watts to-2000,-4500 watts, Qv:-12000 to 12000 watts) however, the optimum shading device as 35% over the south external facade of atrium applied but the fully air-conditioned is necessary especially from morning to afternoon time. It found that, while the floor height of the total building and atrium height increased, heat transferring massively occurred during morning time especially as passive performance. [ABSTRACT FROM AUTHOR]

Heat exchanger is one of the key components for process-heat transfer application in industries. Heat transfer process is time variant, nonlinear and is subjected to disturbances due to fluid flow and reactions. To effectively control the entire process, intelligent and cognitive controllers are being employed due to their self-learning and adaptation properties. BELBIC is a bio-inspired process imitating the behaviour of limbic system of mammalian brain. In this paper a generalized approach for the formulation of BELBIC parameters is presented. The focus of the paper is on design of BELBIC and formulation of nonlinear emotional cues for process control, proposed emotional cues has high capability of adaptation, to improve the system performance in terms of transient and steady state performance. The steady state performance is improved by a factor of 10 with non-linear ECs. Performance measure of ISE is minimum with and without disturbances in the process of heat exchanger control, as compared to PID and existing controllers. [ABSTRACT FROM AUTHOR]

The solution of the problem obtained using Homotopy Perturbation Method (HPM) in this paper. Considered the boundary layer fluid flow over porous medium with chemical reactions and heat transfer. Using Similarity variables in non-linear PDE it will be reduced to ordinary DE then the solution found using HPM. The fluid flow features and the different values of governing parameters are analysed using graphs. [ABSTRACT FROM AUTHOR]

Heat exchangers are a common heat transfer mechanism used in a variety of applications ranging from home to industrial, aircraft, and vehicles. The aim of this research is to study the hydrothermal efficiency of a double pipe heat exchanger with helical fins on annular side of counter flow heat exchanger numerically and compare the results of a double tube with and without screw tape. The investigation begins by employing numerical modeling of helical tapes under different configurations, with different pitches (10, 15, and 20) mm and one height of 10 mm as passive heat transfer augmentation strategies, which are simulated using ANSYS 2022 R1 software. The findings reveal that the current work's numerical results and earlier research's experimental findings are in good accord. Furthermore, while using (Helical Tap Insert) (HTI), the thermal performance of the new typical is found to be better than the typical model. Furthermore, it was found that the Nusselt number achieves the highest growth when the pitch (p) is (20) mm and increases the pressure drop. Furthermore, it was discovered that when the pitch (p) is (20) mm and pressure drop is increased, the Nusselt number grows the most. Furthermore, as associated to the typical model, the total thermal effectiveness of heat exchanger for the new model has greater by 9.9%. This difference is due to the fact that in the theoretical study, ideal conditions are assumed. The experimental design, the assumptions, operating circumstances, and accuracy of the devices are taken into account. It was noted that the value of the specified percentage of hydrothermal improvement achieved the highest value in performance for the same case that was with spiral fin and pitch length (20) mm, which is 1.6% compared to the traditional model. [ABSTRACT FROM AUTHOR]

Photovoltaic thermal, (PV-T) collector is hybrid collector utilized to convert solar rays to usable electrical as well as thermal energy. Lately, the research field on PV-T has focused on enhancing the PV-T collector efficiency via substituting conventional fluids as heat transfer medium with different types of nanofluid. This paper investigated the outcome of a mixture of hybrid nanofluid on useful outcome energy and the gained efficiency of PV-T collector by using a specific fractions of Al2O3-SiC-TiO2 nano particles with water as a cooling fluid. The work showed that at a mixture ratio of volume fraction of ternary hybrid nanofluid with an equal proportion of each component (0.4 vol. fraction), the electrical as well as the thermal efficiencies of PV-T collector at using Al2O3-SiC-TiO2)/water nanofluid are12.83% and 78.7%, respectively. Also, the cells temperatures drop by 15ᵒC with a volume flow-rate 4 L/m of Al2O3-SiC-TiO2/water nanofluid. This study concludes that by utilizing Al2O3-SiC-TiO2/water nanofluid an overall maximum thermal efficiency could reach to 85.3%, and this present 39.7% enhancement the collector performance compared to using pure water. A 42% improvement in electrical efficiency was also observed compare to that of uncooled PV panel efficiency. [ABSTRACT FROM AUTHOR]

The paper presents the efficient parallel algorithms for solving the heat equations for the permafrost models. By using the finite difference scheme, we transform the Stefan problem into the problem of solving multiple systems of linear algebraic equations. These systems have tridiagonal coefficient matrices and are solved by the sweep method. On the base of the parallel algorithms, we developed the codes for multicore CPU with OpenMP technology and for GPU with CUDA technology. The novel approach was proposed to achieve the efficient memory access patterns. Numerical experiments show that our new code is up to 2x faster than the previous one, and the GPU implementation achieves a tenfold speedup compared to the serial CPU code. [ABSTRACT FROM AUTHOR]

The experimental process carried out in this paper is to determine the convection heat transfer coefficient, overall heat transfer coefficient, and nanofluid heat transfer rate based on DWCNT (double-wall carbon nanotube) nanotubes applied to a shell and tube heat exchanger. The advantage of using DWCNT nanoparticles is the high thermal conductivity value. The volume fractions of nanoparticles were 0.1%, 0.3%, and 0.5% with the addition of PVP surfactant. Experimental tests were conducted to determine the heat transfer performance applied to a shell and tube type heat exchanger with upright baffles. This study aims to improve the heat transfer performance by utilizing nanofluids based on DWCNTs nanoparticles. As a result, using DWCNT nanofluids instead of base fluids increases the convective heat transfer coefficient values and overall heat transfer. The increase in the volume fraction of DWCNTs nanoparticles is also accompanied by an increase in the heat generated. The highest thermal conductivity was obtained by adding 0.5% volume of DWCNTs nanoparticles, which was 0.640 W/m.K. The highest heat transfer rate was produced by adding 0.5% volume fraction and 0.02% PVP with a result value of 70.191 W. [ABSTRACT FROM AUTHOR]

The present paper studies the scientific investigation of heat convection and mass transmission of flow past through exponentially expedite parabolic motion effects over a upright plate through cross diffusion and taking an account of the soret and dufourimpacts. The fluid past a dramatically quickened boundless isothermal plate is vertical in the presence of time, flexible heat and mass are elevated linearly has been considered. Utilizing explicit finite difference technique, the undimensioned principal equations are explained graphically through the profiles of velocity,temperature and concentration for pertinent measures of skin-friction, Sherwood number and Nusselt number. [ABSTRACT FROM AUTHOR]

Currently the problem of researching the thermal effect of an electron beam on through-target material, and also researching the physical limitations for maximum power value of microfocus X-ray tubes is relevant. Experimental research of anode thermal operation modes in transmission-type targets of microfocus X-ray tubes is a complex task. The use of modern software systems capable of numerically simulating problems of mathematical physics makes it possible to obtain results that are acceptable in terms of their accuracy. In this paper used a mathematical model developed in the COMSOL Multiphysics 5.4, which makes it possible to simulate heat transfer processes in solids under the conditions of conjugate heat transfer. [ABSTRACT FROM AUTHOR]

The existing study of the paper using chemical reaction examines the consequences of thermal and mass transferal on MHD Alumina nanofluid energy passed over an oscillatory plate by radiation. Using similarity transformations, the governing equations are reformed into dimensionless equations and solved through Laplace Transformation. The effects of parameters in radiation (R), Schmidt number (Sc), Prandtl number (Pr), magnetic parameter (M), chemical Reaction Parameter (Kc), solid volume fraction (ϕ), thermal Grashof number (Gr), mass Grashof number (Gc), phase angle (ω) are scrutinized in velocity, temperature, and concentration forms. The depicted charts are shown the enhancement of the velocity, temperature, and concentration. It observes that an increment of magnetohydrodynamic diminishes the velocity, an increment of thermal and mass Grashof number stand out towards the increase through the velocities, and increasing radiation reduces a temperature. An increment of Schmidt number diminishes the concentration of the Alumina nanofluid. The Concentration of the fluid decreases as an increment of chemical reactive parameters. The increment in time directs to increase the Nusselt number along with the Sherwood number. The skin friction Coefficient improvements with accumulative values of mass grashof number and radiation. [ABSTRACT FROM AUTHOR]

The experimental process is carried out in this paper to determine the value of the convection heat transfer coefficient, overall heat transfer coefficient, and the rate of heat transfer for nanofluids based on DWCNTs (double-wall carbon nanotubes) nanoparticles which ar e applied to shell and tube heat exchangers. The advantage of using DWCNTs nanoparticles is the high thermal conductivity value. The volume fractions of nanoparticles were 0.1%, 0.3%, and 0.5%. Tests were carried out to determine the heat transfer performance applied to the shell and tube type of baffle and no-baffle heat exchanger tools. The purpose of this research is to improve the heat transfer performance by utilizing nanofluids based on DWCNT nanoparticles. The results show an increase in the value of the convection heat transfer coefficient and the overall heat transfer coefficient when using DWCNTs nanofluids rather than using base fluids. [ABSTRACT FROM AUTHOR]

Rotational moulding is a polymer powder processing technique used to make large, hollow plastic products. The heating phase in this process influences both the final product wall thickness distribution as well as the mechanical properties and aesthetical appearance. In this paper a model to calculate the heat transfer is developed. This is done using a 1D thermal finite difference technique with dynamically changing boundary conditions. Compared to the models found in the literature, the deposition process is done in a discrete manner. Density and thermal conductivity are changed according to the progress of the sinter process using Bellehumeur's equation for the coalescence of two grains. The first part of the paper will focus on a theoretical description of the model, the second part on the experimental validation. A close agreement between experimental data and numerical results was found. [ABSTRACT FROM AUTHOR]

The design, modeling, and integration of high-temperature particle storage bins is a critical component of Gen. 3 concentrated solar power (CSP). Particle storage bins control the temperature and flow rates throughout the particle circulatory system, so having a fundamental understanding of their transient thermal behavior is highly advantageous for the design and multi-level control of future CSP systems. This paper provides contributions to this understanding by presenting a semi-analytic method for modeling the transient thermal behavior of bulk particle bins. The model is verified with experiments and a baseline CFD model and then used to make conclusions about the dominant heat transfer modes in bulk particle bins and the general transient thermal performance of related systems. [ABSTRACT FROM AUTHOR]

The paper studies process coextrusion of the three-layers insulation coating. The main focus this investigation is the analysis effect rheological and thermophysical characteristics on the process of heat and mass transfer in the forming tool. In this paper consider six sample polyethylene. Model have been implemented by through of the finite volume method in Ansys software package. Dependency graphs for temperature, pressure along the channels lengths and temperature fields have been obtained. [ABSTRACT FROM AUTHOR]

A recent method of energy test for refrigerator requires two temperature test condition and lower airspeed of the temperature chamber. The testing technology laboratory of the Indonesian Institute of Sciences has developed a temperature chamber capable of conducting the test. This paper presents the heat transfer characteristic of the proposed configuration for heat exchanger for temperature chamber design. An aligned and staggered configuration is investigated in the current study as the proposed configuration of the heat exchanger through numerical modelling. Three parameters of heat transfer characteristics are determined in this current paper: heat transfer rate, heat transfer coefficient, and pressure loss. The result shows that the staggered results in higher heat transfer rate and heat transfer coefficient. Such greater heat transfer values may occur since the greater amount of bank for staggered configuration, and thus provide a greater area for fluid behavior. The verification model indicates a far gap at around 75% relative to the theoretical determination. The growth rate of 1.1 in the mesh sizing is not enough to provide a small sizing that may be indicated as a factor to such a considerable gap. The implication of the greater heat transfer space in staggered configuration brings to the concern of energy consumption for fan-speed as a result of greater pressure loss. The energy need for fan speed for staggered configuration is 1.66% higher of aligned configuration. [ABSTRACT FROM AUTHOR]

Under the high temperature conditioning in fireground and in order to protect people with high temperature protective clothing, this paper has divided the structure of human body into four parts according to characteristics of human body structure and established the heat transmission model from interior side of human body-skin layer-gap layer-protective clothing layer-environment. The temperature distribution situation has been summarized with explicit difference method and C-N implicit difference method respectively. By comparing the actual situation in fireground, the protective clothing can protect people under both two different methods which illustrates that this model is suitable for solving the temperature change of special clothing for high temperature operation. Considering the human skin stratification and compared with the explicit difference, the deviation of implicit difference solution is smaller. The model solution method in this paper is more stable and the result is more suitable to actual situation. [ABSTRACT FROM AUTHOR]