Showing papers by "Asif Afzal published in 2020"

Effect of nano-graphene oxide and n-butanol fuel additives blended with diesel-Nigella sativa biodiesel fuel emulsion on diesel engine characteristics

Abstract: The present investigation uses a blend of Nigella sativa biodiesel, diesel, n-butanol, and graphene oxide nanoparticles to enhance the performance, combustion and symmetric characteristics and to reduce the emissions from the diesel engine of a modified common rail direct injection (CRDI). A symmetric toroidal-type combustion chamber and a six-hole solenoid fuel injector were used in the current investigation. The research aimed to study the effect of two fuel additives, n-butanol and synthesized asymmetric graphene oxide nanoparticles, in improving the fuel properties of Nigella sativa biodiesel (NSME25). The concentration of n-butanol (10%) was kept constant, and asymmetric graphene oxide nano-additive and sodium dodecyl benzene sulphonate (SDBS) surfactant were added to n-butanol and NSME25 in the form of nanofluid in varying proportions. The nanofluids were prepared using a probe sonication process to prevent nanoparticles from agglomerating in the base fluid. The process was repeated for biodiesel, n-butanol and nanofluid, and four different stable and symmetric nanofuel mixtures were prepared by varying the graphene oxide (30, 60, 90 and 120 ppm). The nanofuel blend NSME25B10GO90 displayed an enhancement in the brake thermal efficiency (BTE) and a reduction in brake-specific fuel consumption (BSFC) at maximum load due to high catalytic activity and the enhanced microexplosion phenomenon developed by graphene oxide nanoparticles. The heat release rate (HRR), in-cylinder temperature increased, while exhaust gas temperature (EGT) decreased. Smoke, hydrocarbon (HC), carbon monoxide (CO2) and carbon monoxide (CO) emissions also fell, in a trade-off with marginally increased NOx, for all nanofuel blends, compared with Nigella sativa biodiesel. The results obtained indicates that 90 ppm of graphene oxide nanoparticles and 10% n-butanol in Nigella sativa biodiesel are comparable with diesel fuel.

Study of diesel engine characteristics by adding nanosized zinc oxide and diethyl ether additives in Mahua biodiesel–diesel fuel blend

Abstract: This study deals with an experimental investigation to assess the characteristics of a modified common rail direct injection (CRDI) engine utilizing diesel, Mahua biodiesel, and their blends with synthesized zinc oxide (ZnO) nano additives. The physicochemical properties of diesel, diesel + 30 ppm ZnO nanoparticles (D10030), 20% Mahua biodiesel (MOME20), and Mahua biodiesel (20%) + 30 ppm ZnO nanoparticles (MOME2030) were measured in accordance to the American Society for Testing and Materials standards. The effects of modification of fuel injectors (FI) holes (7-hole FI) and toroidal reentrant combustion chamber (TRCC) piston bowl design on the performance of CRDI using different fuel blends were assessed. For injection timings (IT) and injection opening pressure (IOP) average increase in brake thermal efficiency for fuel blend D10030 and MOME2030 was 9.65% and 16.4%, and 8.83% and 5.06%, respectively. Also, for IT and IOP, the average reductions in brake specific fuel consumption, smoke, carbon monoxide, hydrocarbon and nitrogen oxide emissions for D10030 and MOME2030 were 10.9% and 7.7%, 18.2% and 8.6%, 12.6% and 11.5%, 8.74% and 13.1%, and 5.75% and 7.79%, respectively and 15.5% and 5.06%, 20.33% and 6.20%, 11.12% and 24.8%, 18.32% and 6.29%, and 1.79% and 6.89%, respectively for 7-hole fuel injector and TRCC. The cylinder pressure and heat release rate for D10030 and MOME2030 were enhanced by 6.8% and 17.1%, and 7.35% and 12.28%. The 7-hole fuel injector with the nano fuel blends at an injection timing and pressure of 10° btdc and 900 bar demonstrated the overall improvement of the engine characteristics due to the better air quality for fuel mixing. Similarly, the TRCC cylinder bowl geometry illustrated advanced ignition due to an improved swirl and turbulence. Also, the engine test results demonstrated that 30 ppm of ZnO nanoparticles in Mahua biodiesel (MOME2030) and diesel (D10030) with diethyl ether resulted overall enhancement of CRDI engine characteristics.

Investigation on the effect of cottonseed oil blended with different percentages of octanol and suspended MWCNT nanoparticles on diesel engine characteristics

Abstract: In the present work, a series of experiments were designed and conducted to prepare biodiesel from cottonseed oil and to blend it with octanol. The thermal and mass transfer characteristics of the biodiesel were further improved by adding functionalized multi-walled carbon nanotubes (MWCNTs). The performance of the engine with the blended fuel was analyzed through characterization and measurement of the gas emissions from the engine. Four blends of cottonseed oil (B20, B40, B60, and B100) were prepared initially, and each blend was added with octanol additive of 5%, 10%, and 15% together with 3% of functionalized MWCNTs by mass. The performance analysis showed that B20 with 5%, 10%, and 15% octanol represented relatively lower brake specific fuel consumption relative to all test fuels. Likewise, the addition of MWCNT nanoparticle further stabilized the rate of fuel consumption and brake thermal efficiency. It was also identified that at larger values of diesel and biodiesel blends, the performance and also the quantity of gas emission were the same.

Enhancement in Combustion, Performance, and Emission Characteristics of a Diesel Engine Fueled with Ce-ZnO Nanoparticle Additive Added to Soybean Biodiesel Blends

Abstract: This study considered the impacts of diesel–soybean biodiesel blends mixed with 3% cerium coated zinc oxide (Ce-ZnO) nanoparticles on the performance, emission, and combustion characteristics of a single cylinder diesel engine. The fuel blends were prepared using 25% soybean biodiesel in diesel (SBME25). Ce-ZnO nanoparticle additives were blended with SBME25 at 25, 50, and 75 ppm using the ultrasonication process with a surfactant (Span 80) at 2 vol.% to enhance the stability of the blend. A variable compression ratio engine operated at a 19.5:1 compression ratio (CR) using these blends resulted in an improvement in overall engine characteristics. With 50 ppm Ce-ZnO nanoparticle additive in SBME25 (SBME25Ce-ZnO50), the brake thermal efficiency (BTE) and heat release rate (HRR) increased by 20.66% and 18.1%, respectively; brake specific fuel consumption (BSFC) by 21.81%; and the CO, smoke, and hydrocarbon (HC) decreased by 30%, 18.7%, and 21.5%, respectively, compared to SBME25 fuel operation. However, the oxides of nitrogen slightly rose for all the nanoparticle added blends. As such, 50 ppm of Ce-ZnO nanoparticle in the blend is a potent choice for the enhancement of engine performance, combustion, and emission characteristics.

Optimum location and influence of tilt angle on performance of solar PV panels

Abstract: With the growing demand of economically feasible, clean, and renewable energy, the use of solar photovoltaic (PV) systems is increasing. The PV panel performance to generate electrical energy depends on many factors among which tilt angle is also a crucial one. Among hundreds of research work performed pertinent to solar PV panels performance, this work critically reviews the role of tilt angles and particularly locating the optimum tilt angle using different methods. The past data collected for analysis can be categorized mainly into mathematical model based, experimental based, simulation based, or combination of any of these. Single-axis tracking, dual-axis tracking, simple glass cover, hydrophobic glass cover, soiled glass, clean glass, partial shadow, use of phase-change material, computational fluid dynamic analysis, etc., are the novel methods found in the literature for analysis and locating the optimum tilt angle. For illustration purpose, few figures are provided in which the optimum tilt angle obtained on monthly, seasonally, and annual basis is shown. Research works are growing in the field of computations and simulations using online software and codes. Pure mathematical-based calculations are also reported but the trend is to combine this method with the simulation method. As the PV panel performance is found to be affected by number of parameters, their consideration in any single study is not reported. In future, work is required to carry out the experiment or simulation considering the effect of soiling, glass material, temperature, and surrounding ambience on the location of optimum tilt angle. As a whole, the optimum tilt angles reported for locations exactly on the equator line, i.e., 0° latitude, ranges between − 2.5° and 2.5°, for locations just above the equator line, i.e., latitude 2.6°–30° N ranges between 5° and 28°, for 40°–70° N, it is 29°–40°, and for 71°–90° N, it is 41°–45°. For locations at 2.6°–30° S, optimum tilt angles range between − 4° and − 32°, 30°–46° S, it is − 33° to − 36°, 47°–65° S, it is − 34° to − 50°, and for 66°–90° S it is − 51° to − 62°.

Multi-objective optimization of thermal performance in battery system using genetic and particle swarm algorithm combined with fuzzy logics

Abstract: A novel technique for multi-objective optimization of thermal management in battery system using hybrid Genetic algorithm and Fuzzy logic is developed. Secondly, Particle Swarm Optimization algorithm combined with Fuzzy logic is also proposed for the same. The combined algorithms and fitness function for fitness evaluation is written in-house C code. For the thermal performance fitness evaluation, realistic conjugate heat transfer condition at the battery and coolant interface is adopted. The objective functions are average Nusselt number, friction coefficient, and maximum temperature. Maximizing one causes proportional increase in another, hence to achieve a moderate condition of better Nusselt number with low pumping power cost and temperature within allowable limits, these algorithms assist in optimization. Five different independent operating parameters are selected for the Multi-objective optimization and brief results are presented. The Fuzzy logic membership functions adopted can be easily modified/selected by the user to suite the battery thermal problem at hand and to assign weight to each fitness function. The fitness function obtained using the proposed multi-objective optimization technique are closer and indicate safe temperature of battery with enhanced Nusselt number and minimum friction coefficient. The maximum multi-objective fitness obtained after normalization is 0.9.

Investigation and back-propagation modeling of base pressure at sonic and supersonic Mach numbers

Abstract: The experimental analysis of base pressure in a high-speed compressible flow is carried out. The flow is made to expand abruptly from the nozzle into an enlarged duct at fifteen sonic and supersonic Mach numbers. The analysis is made for variation in the nozzle pressure ratio (NPR), length to diameter ratio, and area ratio. The effect of active micro-jets on the base and wall pressure is assessed. The data visualization of the huge experimental data generated is performed using heat maps. For the first time, six back-propagation neural network models (BPMs) are developed based on input and output possibilities to predict the pressure in high-speed flows. The experimental analysis revealed that depending upon the type of expansion, the base pressure changes. A jet of air blown at the base using micro-jets is found to be effective in increasing the base pressure during the under-expansion regime, while the wall pressure remains unaffected. The data visualization provided an insight into the highest impact on the base pressure by the NPR. The six BPMs with two hidden layers having four neurons per layer are found to be most suitable for the regression analysis. BPM 5 and BPM 6 accurately predict the highly non-linear data of the base and wall pressure.

Thermal analyses of minichannels and use of mathematical and numerical models

Abstract: Growth in electronic devices comes with a challenge to engineers to provide proficient cooling mechanism in order to evade performance decline. Minichannel heat sinks are one among type of cooling ...

Maximum temperature analysis in a Li-ion battery pack cooled by different fluids

Abstract: The use of Li-ion battery in electric vehicles is becoming extensive in the modern-day world owing to their high energy density and longer life. But there is a concern of proper thermal management to have consistent performance. Therefore, proper cooling mechanism to have a good life and reliability on the battery system is necessary. The main objective of this analysis is to assess the maximum temperature that causes thermal runaway when the battery pack is cooled by several fluids. Five categories of coolants are passed over the heat-generating battery pack to extract the heat and keep the temperature in the limit. Different kinds of gases, conventional oils, thermal oils, nanofluids, and liquid metals are adopted as coolants in each category. This analysis is a novel study which considers different categories of coolant and conjugate heat transfer condition at the battery pack and coolant interface. In each group of coolant, five types of fluids are selected and analyzed to obtain the least maximum temperature of battery. The flow Reynolds number (Re), heat generation (Qgen), and conductivity ratio (Cr) are other parameters considered for the analysis. The Nusselt number for air and water as coolant with increase in Re is studied separately at the end. The maximum temperature is found to increase with Qgen and decrease for Re and Cr. Thermal oils, nanofluids, and liquid metals are found to provide maximum temperature in the same range of 0.62 to 0.54. At the same time, gases have nearly the same effect at different values of Re and Cr.

Waste coconut oil methyl ester with and without additives as an alternative fuel in diesel engine at two different injection pressures

Abstract: The performance and emission from diesel engine using biodiesel from waste coconut oil (WCOO) with and without additives is accessed in this article. WCOO biodiesel is produced from coconuts which ...

Steady and Transient State Analyses on Conjugate Laminar Forced Convection Heat Transfer

Abstract: The term ‘conjugate heat transfer’ refers to a heat transfer process involving an interaction of heat conduction within a solid body with either of the free, forced, and mixed convection from its surface to a fluid flowing over it. It finds application in numerous fields starting from thermal interaction between surrounding air and fins to thermal interaction between flowing fluid and turbine blades. In this article, a systematic literature review of studies pertinent to laminar conjugate conduction-forced convection heat transfer analysis subjected to internal and external flow conditions is performed. The review reports both steady and unsteady state analyses related to experimental, analytical and numerical investigations, in both rectangular and cylindrical geometries with an exemption to micro and mini channel related studies. The studies are categorically put forth initially and an overview of these studies is presented in tabular and graphical form for a swift glance later under each section. This paper is concluded highlighting the salient features of the review, with respect to physical and mathematical models, methodology and applications. The challenges and scope for future study reported at the end of this paper gives the reader an insight into the gaps in the area of conjugate heat transfer analysis of steady and transient state under laminar forced convection flow regimes.

Hydrogen Injection in a Dual Fuel Engine Fueled with Low-Pressure Injection of Methyl Ester of Thevetia Peruviana (METP) for Diesel Engine Maintenance Application

Abstract: The present work is mapped to scrutinize the consequence of biodiesel and gaseous fuel properties, and their impact on compression-ignition (CI) engine combustion and emission characteristics in single and dual fuel operation. Biodiesel prepared from non-edible oil source derived from Thevetia peruviana belonging to the plant family of Apocynaceaeis. The fuel has been referred as methyl ester of Thevetia peruviana (METP) and adopted as pilot fuel for the effective combustion of compressed gaseous fuel of hydrogen. This investigation is an effort to augment the engine performance of a biodiesel-gaseous fueled diesel engine operated under varied engine parameters. Subsequently, consequences of gas flow rate, injection timing, gas entry type, and manifold gas injection on the modified dual-fuel engine using conventional mechanical fuel injections (CMFIS) for optimum engine performance were investigated. Fuel consumption, CO, UHC, and smoke formations are spotted to be less besides higher NOx emissions compared to CMFIS operation. The fuel burning features such as ignition delay, burning interval, and variation of pressure and heat release rates with crank angle are scrutinized and compared with base fuel. Sustained research in this direction can convey practical engine technology, concerning fuel combinations in the dual fuel mode, paving the way to alternatives which counter the continued fossil fuel utilization that has detrimental impacts on the climate.

Computational finite element analysis of brake disc rotors employing different materials

Abstract: In this paper, numerical simulation of transient thermal and static structural analysis was performed here sequentially with coupled thermo-structural method. Numerical procedure of calculation was...

Optimum spacing between grooved tubes: An experimental study

Abstract: An experimental study on optimum spacing between grooved tubes is reported in this paper. Two grooved tubes having pitch of 10 mm and 15 mm and a plain tube were considered for the heat transfer analysis. The spacing between two tubes with same pitch was varied from 10 mm to 35 mm with a step size of 5 mm. Velocity of air flowing over the tube surfaces was changed from 0.4 m/s to 1 m/s using a blower fan. Based on Nusselt number (Nu) the optimum spacing between the tubes was decided. The optimum spacing between grooved tubes of pitch 10 mm and 15 mm was compared with that of plain tubes. From the experimental analysis it was noticed that with increase in air velocity (increase in Reynolds number) the tube surface temperature reduced irrespective of any tube considered. Nu increased with increase in air velocity for all the tubes. The important conclusion drawn from the present study was that, there exists a limiting spacing (optimum) between the tubes above which no change in Nu was observed. Spacing of 30 mm was found to be the optimum spacing between the tubes irrespective of its surface geometry modifications.

Parallelization of Numerical Conjugate Heat Transfer Analysis in Parallel Plate Channel Using OpenMP

Abstract: Conjugate heat transfer and fluid flow is a common phenomenon occurring in parallel plate channels. Finite volume method (FVM) formulation-based semi-implicit pressure linked equations algorithm is a common technique to solve the Navier–Stokes equation for fluid flow simulation in such phenomena, which is computationally expensive. In this article, an indigenous FVM code is developed for numerical analysis of conjugate heat transfer and fluid flow, considering different problems. The computational time spent by the code is found to be around 90% of total execution time in solving the pressure (P) correction equation. The remaining time is spent on U, V velocity, and temperature (T) functions, which use tri-diagonal matrix algorithm. To carry out the numerical analysis faster, the developed FVM code is parallelized using OpenMP paradigm. All the functions of the code (U, V, T, and P) are parallelized using OpenMP, and the parallel performance is analyzed for different fluid flow, grid size, and boundary conditions. Using nested and without nested OpenMP parallelization, analysis is done on different computing machines having different configurations. From the complete analysis, it is observed that flow Reynolds number (Re) has a significant impact on the sequential execution time of the FVM code but has a negligible role in effecting speedup and parallel efficiency. OpenMP parallelization of the FVM code provides a maximum speedup of up to 1.5 for considered conditions.

The potential of nanoparticle additives in biodiesel: A fundamental outset

Abstract: Biodiesel is an unparalleled alternative fuel source envisioned to encompass the significance of diesel fuel and reduce greenhouse gas emissions because to its locked carbon cycle. However, it increases the nitrogen oxide emission, regular engine parts replacement due to clogging, and is not suitable in cold weather conditions. The addition of nanoparticles (metallic, non-metallic, oxygenated, organic and amalgamation) with diesel-biodiesel emulsion fuels results in an enhancement in the engine performance, thermo-physical properties, enrichment in the heat transfer rate, the equilibrium of the fuel mixtures and drop in the exhaust emissions reliant on the prescription of nanoparticle additives. The review intends to demonstrate the most recent nanoparticle additives used in diesel-biodiesel fuels.

Numerical investigation on pressure-driven electro osmatic flow and mixing in a constricted micro channel by triangular obstacle

Abstract: The characteristics of fluid motions in micro-channel are strong fluid-wall surface interactions, high surface to volume ratio, extremely low Reynolds number laminar flow, surface roughness and wall surface or zeta potential. Due to zeta potential, an electrical double layer (EDL) is formed in the vicinity of the wall surface, namely, the stern layer (layer of immobile ions) and diffuse layer (layer of mobile ions). Hence, its competent designs demand more efficient micro-scale mixing mechanisms. This paper aims to therefore carry out numerical investigations of electro osmotic flow and mixing in a constricted microchannel by modifying the existing immersed boundary method.,The numerical solution of electro-osmotic flow is obtained by linking Navier–Stokes equation with Poisson and Nernst–Planck equation for electric field and transportation of ion, respectively. Fluids with different concentrations enter the microchannel and its mixing along its way is simulated by solving the governing equation specified for the concentration field. Both the electro-osmotic effects and channel constriction constitute a hybrid mixing technique, a combination of passive and active methods. In microchannels, the chief factors affecting the mixing efficiency were studied efficiently from results obtained numerically.,The results indicate that the mixing efficiency is influenced with a change in zeta potential (ζ), number of triangular obstacles, EDL thickness (λ). Mixing efficiency decreases with an increment in external electric field strength (Ex), Peclet number (Pe) and Reynolds number (Re). Mixing efficiency is increased from 28.2 to 50.2% with an increase in the number of triangular obstacles from 1 to 5. As the value of Re and Pe is decreased, the overall percentage increase in the mixing efficiency is 56.4% for the case of a mixing micro-channel constricted with five triangular obstacles. It is also vivid that as the EDL overlaps in the micro-channel, the mixing efficiency is 52.7% for the given zeta potential, Re and Pe values. The findings of this study may be useful in biomedical, biotechnological, drug delivery applications, cooling of microchips and deoxyribonucleic acid hybridization.,The process of mixing in microchannels is widely studied due to its application in various microfluidic devices like micro electromechanical systems and lab-on-a-chip devices. Hence, its competent designs demand more efficient micro-scale mixing mechanisms. The present study carries out numerical investigations by modifying the existing immersed boundary method, on pressure-driven electro osmotic flow and mixing in a constricted microchannel using the varied number of triangular obstacles by using a modified immersed boundary method. In microchannels, the theory of EDL combined with pressure-driven flow elucidates the electro-osmotic flow.

Combined Effect of Synthesized Waste Milk Scum Oil Methyl Ester and Ethanol Fuel Blend on the Diesel Engine Characteristics

Abstract: Milk scum is a waste obtained in milk dairies, which can be used as a raw material for producing biodiesel by a transesterification process In this research study, the biodiesel obtained from milk scum was blended with diesel to make binary blends (B20D80, B60D40 and B100) These binary blends were further blended with ethanol in different percentages to make ternary blends (B20E05D75, B20E10D70, B20E15D65) Physical and chemical properties of binary and ternary blends were investigated and compared Degradation of physical properties of the prepared biodiesels with respect to time was studied, which is the salient part of the work Engine performance test was conducted in a single-cylinder diesel engine Performance of the engine for different blends (both binary and ternary) was recorded and compared Addition of 5% ethanol showed a decrease in fuel consumption, whereas higher content (15%) of ethanol showed rapid increase in fuel consumption as compared to that of binary blends Ternary blend containing 5% ethanol showed higher brake thermal efficiency (BTE) compared to D100 (diesel only), while ternary blends containing 10 and 15% ethanol gave lower BTE compared to 5% ethanol and D100 The blend B20E05D75 is considered as better alternative fuel upon comparing mass fuel consumption, air fuel ratio and brake thermal efficiency with all rest of blends tested in this study

Parallel performance analysis of coupled heat and fluid flow in parallel plate channel using CUDA

Abstract: The heat transfer analysis coupled with fluid flow is important in many real-world application areas varying from micro-channels to spacecraft’s. Numerical prediction of thermal and fluid flow situation has become very common method using any computational fluid dynamics software or by developing in-house codes. One of the major issues pertinent to numerical analysis lies with immense computational time required for repeated analysis. In this article, technique applied for parallelization of in-house developed generic code using CUDA and OpenMP paradigm is discussed. The parallelized finite-volume method (FVM)-based code for analysis of various problems is analyzed for different boundary conditions. Two GPUs (graphical processing units) are used for parallel execution. Out of four functions in the code (U, V, P, and T), only P function is parallelized using CUDA as it consumes 91% of computational time and the rest functions are parallelized using OpenMP. Parallel performance analysis is carried out for 400, 625, and 900 threads launched from host for parallel execution. Improvement in speedup using CUDA compared with speedup using complete OpenMP parallelization on different computing machines is also provided. Parallel efficiency of the FVM code for different grid size, Reynolds number, internal flow, and external flow is also carried out. It is found that the GPU provides immense speedup and outperforms OpenMP largely. Parallel execution on GPU gives results in a quite acceptable amount of time. The parallel efficiency is found to be close to 90% in internal flow and 10% for external flow.

Finite element modeling of thermomechanical problems under the vehicle braking process

Abstract: The braking phenomenon is an aspect of vehicle stopping performance where in kinetic energy due to speed of the vehicle is transformed into thermal energy produced by the brake disc and its pads. The heat must then be dissipated into the surrounding structure and into air flow around the brake system. The thermal friction field during the braking phase between the disc and the brake pads can lead to excessive temperatures. In our work, we presented numerical modeling using ANSYS software adapted in the finite element method, to follow the evolution of the global temperatures for the two types of brake discs, full and ventilated discs, during braking scenario. Also, numerical simulation of the transient thermal analysis and the static structural were performed here sequentially, with coupled thermo-structural method. Numerical procedure of calculation relies on important steps such that the Computational Fluid Dynamics (CFD) and thermal analysis have been well illustrated in 3D, showing the effects of heat distribution over the brake disc. This CFD analysis helped us in the calculation of the values of the thermal coefficients (h) that have been exploited in 3D transient evolution of the brake disc temperatures. Three different brake disc materials were tested and comparative analysis of the results was conducted in order, to derive the one with the best thermal behavior. Finally, the resolution of the coupled thermomechanical model allows us to visualize other important results of this research such as the deformations and the equivalent stresses of von Mises of the disc, as well as the contact pressure of the brake pads. Following our analysis and results we draw from it, we derive several conclusions. The choice allowed us to deliver the rotor design excellence to ensure and guarantee the good braking performance of the vehicles.

A predictive tool to evaluate braking system performance using a fully coupled thermo-mechanical finite element model

Abstract: The braking phenomenon is an aspect of vehicle stopping performance where with kinetic energy due to speed of the vehicle is transformed to thermal energy via the friction between the brake disc and its pads. The heat must then be dissipated into the surrounding structure and into airflow around the brake system. The frictional thermal field during the braking phase between the disc and the brake pads can lead to excessive temperatures. In our work, we presented a numerical modeling using ANSYS software adapted in the finite element method, to follow the evolution of the global temperatures for the two types of brake discs, full and ventilated disc during braking scenario. Also, numerical simulation of the transient thermal and the static structural analysis were performed here sequentially, with coupled thermo-structural method. Numerical procedure of calculation relies on important steps such that the Computational Fluid Dynamics (CFD) and thermal analysis have been well illustrated in 3D, showing the effects of heat distribution over the brake disc. This CFD approach helped in the calculation of the values of the thermal coefficients (h) that have been exploited in the 3D transient evolution of the brake disc temperatures. Three different brake disc materials were tested and comparative analysis of the results was conducted in order, to derive the one with the best thermal behavior. Finally, the resolution of the coupled thermomechanical model allows us to visualize other important results of this research such as; the deformations, and the equivalent stresses of Von Mises of the disc, as well as the contact pressure of the brake pads. Following our analysis and results we draw from it, we derive several conclusions. The choice allowed us to deliver the rotor design excellence to ensure and guarantee the good braking performance of the vehicles.

Impact of Curved Vents, Holes and Slots on Thermo-mechanical Behavior of Automobile Disc Brake - FEM Simulation and Validation

Abstract: Ventilated discs have gained significant attraction for automobile disc brake due to enhanced thermal performance, but the optimal choice needs careful analysis of thermal and structural behaviors. Following the previous studies on solid and straight ventilated discs, the present study considers discs with three new ventilation patterns namely curved vents, curved vents with holes and curved vents with holes and slots. Three-dimensional modeling was done by SOLIDWORKS 15, and finite element simulation was performed by ANSYS 15. In the thermal analysis, the temperature history during one braking cycle was studied for each model, and the structural parameters analyzed include total deformation, Von Mises stress and contact pressure. The study shows that changing from straight vents to curved vents improves thermal performance without affecting the mechanical behavior. Moreover, the thermo-mechanical behavior is further improved by adding holes and slots on the surface, along with curved vents.