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Öğe Basics of heat transfer: Conduction(Elsevier, 2023) Varuvel, E.G.; Sonthalia, A.; Aloui, F.; Saravanan, C.G.In this chapter the fundamental concepts of thermodynamics are presented. The relation of heat to other forms of energy and the energy balance is also discussed. As a system moves from one equilibrium state to another, thermodynamics can provide the information about the amount of heat transfer. It cannot, however, provide any information on how long the process will take. The design engineers, however, are more interested in the rate of heat transfer. Heat transfer can take place through conduction, convection, and radiation. This chapter further discusses the heat transfer through conduction in detail. It is well known that heat transfer through a medium has magnitude as well as direction. The heat conduction rate in a given direction is proportional to the temperature gradient, that is, the temperature varies with distance in the given direction. In general, heat transfer is three-dimensional and time dependent. The temperature in a medium varies with position as well as with time. If the temperature is independent of time, then conduction is in a steady state otherwise it is in a transient state. This chapter also discusses conduction through plane/composite wall, composite cylinder, and fins. For simplicity the analysis is carried out in one dimension under steady-state conditions. Heat conduction under transient conditions for a lumped system is also discussed. © 2023 Elsevier Inc. All rights reserved.Öğe Basics of heat transfer: Convection(Elsevier, 2023) Varuvel, E.G.; Sonthalia, A.; Aloui, F.; Saravanan, C.G.This chapter discusses the mechanism of heat transfer through the motion of the bulk fluid also known as convection. This heat transfer can be either forced or free depending on how the initiation of the fluid motion takes place. In forced convection, a pump or a fan is used to force the fluid to flow through a pipe or over a surface. While fluid motion by natural means such as buoyancy (warmer fluid rises) takes place in natural convection. Another way of classifying convection is it can be either external or internal. When a fluid flows over a surface it is known as external flow and when it flows through a duct it can be classified as internal flow. © 2023 Elsevier Inc. All rights reserved.Öğe Basics of heat transfer: Heat exchanger(Elsevier, 2023) Varuvel, E.G.; Sonthalia, A.; Aloui, F.; Saravanan, C.G.Heat exchangers facilitate the exchange of heat between two fluids having different temperatures. The heat exchange involves conduction between the walls separating the fluids and convection in each fluid. The chapter starts with the discussion on classification of heat exchangers. Then the overall heat transfer coefficient and log mean temperature difference (LMTD) for different configurations of heat exchanger is discussed. As the heat exchanger gets fouled over a period of time a fouling factor is introduced that considers the variation in LMTD. Similarly, a correction factor is introduced for multi-pass arrangements. The effectiveness—number of transfer units (NTU) method is also discussed for analyzing the heat exchanger when the outlet temperature of the fluids is unknown. Lastly, selecting the heat exchanger for a particular application is also briefly discussed. © 2023 Elsevier Inc. All rights reserved.Öğe Effect of intake port design modifications on diesel engine characteristics fuelled by pine oil-diesel blends(Taylor and Francis, 2022) Malaiperumal, V.; Saravanan, C.G.; Raman, V.; Kirubagaran, R.K.; Pandiarajan, P.; Sonthalia, A.; Varuvel, E.G.The effect of the modified intake port with various inclined nozzle angles such as 30°, 60°, and 90° on the diesel engine characteristics when operated with pine oil-diesel blends is investigated. Prior to the engine experimental study, a computational analysis was performed to investigate the impact produced on the flow field parameters of an engine due to modified intake port design. The numerical study revealed increased swirl velocity and turbulence for intake port with a 60° single-pass configuration compared to other design configurations. With evidence of improved swirl velocity and the proposed modified intake port design from the numerical study, an experimental investigation was performed using pine oil blends in the diesel engine with modified intake port configurations. The preliminary engine test findings with standard intake port design indicated that P50 (50% pine oil + 50% diesel) has higher peak engine cylinder pressure and heat release rates than P10 (10% pine oil + 90% diesel). Additionally, the 60° single-pass configuration showed further increase in peak pressure and peak heat release followed by standard and other intake port design configurations. At high load, the P50 blend showed a 12.3% increase in BTE for 60° intake port design configuration in comparison to the standard design configuration. While for the same blend, the engine out emissions like hydrocarbon (HC) and smoke were reduced by about 6.6% and 17.6%, respectively, and nitrogen oxide (NOX) emission was increased by 29% for the 60° single-pass configuration when compared to the standard design configuration. Overall, the intended intake port design modification strategy increased the swirl velocity and turbulence, which improved the air/fuel mixing and combustion. This study identifies 60° single-pass configuration as an optimum design on account of the aforementioned improved engine combustion, performance, and emissions. © 2022 Taylor & Francis Group, LLC.Öğe EXTENSION OF LEAN LIMIT USING HYDROGEN ADDITION FOR GASOLINE DIRECT INJECTION ENGINE AND EMISSION REDUCTION(International Association for Hydrogen Energy, IAHE, 2022) Jerome, Stanley, M.; Leenus, Jesu, Martin, M.; Varuvel, E.G.The effect of hydrogen induction (0-5 liter per minute) in to the intake manifold of the small bore Gasoline Direct Injection (GDI) Engine is investigated experimentally. The intake manifold is slightly modified to accommodate the hydrogen induction system, where premixed mixture of hydrogen and air is formed in the intake manifold; attaining the excess air ratio of 1.0 to 1.2. With the increment of hydrogen fraction the fuel leaning (Gasoline) is attained and achieving economical fuel consumption rate. The decrement in torque characteristics is compensated with the increase of hydrogen fraction. The hydrogen induction improves the combustion rate and mean effective pressure; shortens the flame propagation, maximize the heat release rate and peak pressure attainment. On the emission side consistent decrease in CO and HC emission; and increase of NOx emission since the mean gas temperature has increased. The cycle to cycle variation during the lean operating condition at 1.2 shows the combustion stability and effective flame propagation. © 2022 Proceedings of WHEC 2022 - 23rd World Hydrogen Energy Conference: Bridging Continents by H2. All rights reserved.Öğe Handbook of Thermal Management Systems: E-Mobility and Other Energy Applications(Elsevier, 2023) Aloui, F.; Varuvel, E.G.; Sonthalia, A.Handbook of Thermal Management Systems: e-Mobility and Other Energy Applications is a comprehensive reference on the thermal management of key renewable energy sources and other electronic components. With an emphasis on practical applications, the book addresses thermal management systems of batteries, fuel cells, solar panels, electric motors, as well as a range of other electronic devices that are crucial for the development of sustainable transport systems. Chapters provide a basic understanding of the thermodynamics behind the development of a thermal management system, update on Batteries, Fuel Cells, Solar Panels, and Other Electronics, provide a detailed description of components, and discuss fundamentals. Dedicated chapters then systematically examine the heating, cooling, and phase changes of each system, supported by numerical analyses, simulations and experimental data. These chapters include discussion of the latest technologies and methods and practical guidance on their application in real-world system-level projects, as well as case studies from engineering systems that are currently in operation. Finally, next-generation technologies and methods are discussed and considered. © 2023 Elsevier Inc. All rights reserved.Öğe Impact of hydrogen addition on diesel engine performance, emissions, combustion, and vibration characteristics using a Prosopis Juliflora methyl ester-decanol blend as pilot fuel(Elsevier Ltd, 2024) Duraisamy, B.; Varuvel, E.G.; Palanichamy, S.; Subramanian, B.; Jerome, Stanley, M.; Madheswaran, D.K.The research primarily focuses on investigating the impact of hydrogen induction on parameters of a compression ignition (CI) engine utilizing biodiesel blended with decanol, up to knock limit. The utilization of non-edible oil, exemplified by Prosopis Juliflora seed oil (JFO), presents inherent challenges due to its elevated viscosity, limited atomization, and suboptimal combustion attributes. However, the conversion of JFO into Prosopis Juliflora methyl ester (JFME) biodiesel substantially ameliorates its fuel characteristics, although it still exhibits relatively lower performance in comparison to conventional diesel fuel. To enhance the attributes of JFME blends, decanol is mixed with 20 % on volumetric basis (referred to as D20). Furthermore, the introduction of hydrogen into the engine's intake manifold is employed to bolster performance and curtail emissions. Different hydrogen flow rates, spanning from 2.5 to 10 litres per minute (lpm), are assessed in conjunction with the D20 biodiesel blend. The inclusion of hydrogen into D20 blends yields an enhancement in brake thermal efficiency (BTE), coupled with reductions in hydrocarbon (HC), carbon monoxide (CO), and smoke emissions. However, it should be noted that hydrogen's notable flame velocity and higher calorific value engender escalated combustion temperatures and an associated rise in Nitric oxide (NO) emission. The research also encompasses an evaluation of engine vibration during dual-fuel operation, revealing a proportional increase in engine vibration with heightened rates of hydrogen induction. In summation, the utilization of D20 in conjunction with hydrogen at a rate of 10 lpm emerges as a viable approach for operating diesel engines in a dual-fuel mode. © 2023 Hydrogen Energy Publications LLCÖğe Need of battery thermal management systems(Elsevier, 2023) Sonthalia, A.; Varuvel, E.G.; Aloui, F.; Saravanan, C.G.Due to thermal runaway issues, the thermal safety of lithium ion battery has always been a concern all over the world. The cell is highly sensitive to temperature and has a narrow operating temperature range. At different temperatures, complex electrochemical reactions take place. The effect of ambient temperature in different seasons and internal heating can cause side reactions leading to thermal runaway which should be considered while designing the battery thermal management system. This chapter focuses on the cause of thermal runaway at all temperature ranges. Such as at low-temperature capacity fade and lithium dendrite and plating can occur causing internal short circuits. At normal temperature range, side reactions can speed up, reducing the battery life while thermal runaway can occur at high temperatures. © 2023 Elsevier Inc. All rights reserved.Öğe NOx emission reduction in low viscous low cetane (LVLC) fuel using additives in CI engine: an experimental study(Springer Science and Business Media Deutschland GmbH, 2024) Sonthalia, A.; Varuvel, E.G.; Subramanian, T.; Kumar, N.This study examines the combustion properties of pine oil (PO), which is classified as a low viscosity, low cetane (LVLC) fuel. It highlights the superior performance of pine oil in comparison to diesel fuel, but acknowledges that its low cetane index causes a delay in combustion initiation, which consequently results in elevated NOx emissions. Fuel atomization, evaporation, and air/fuel mixing are enhanced by the reduced viscosity and boiling point of PO in comparison to diesel. Nevertheless, the low cetane index of PO restricts its applicability as a diesel fuel substitute in CI engines. Due to significant heat release after an extended ignition delay, NOx emissions tend to rise with less viscous and low cetane (LVLC) fuels. A range of cetane improvers, such as diethyl ether (DEE), benzyl alcohol (Bn), diglyme (DGE), and methyl tert-butyl ether (MTBE), have demonstrated effectiveness in mitigating nitrogen oxide (NOx) emissions upon introduction into pine oil. All the cetane improvers were added 5% and 10% by volume with pine oil. A twin-cylinder tractor engine operating at a constant speed of 1500 revolutions per minute was utilized in this testing. In order to achieve a warm-up condition that would enable the smooth operation of PO, the engine was initially operated on diesel fuel. At maximum load condition, NOx emission of PO was higher by 8% in comparison to diesel. NOx emission was significantly reduced with addition of cetane improvers. Maximum reduction of 7% was observed with PO + MTBE 10% in comparison to PO which is in par with diesel. An increase in HC and CO emission was observed with all cetane improver addition with PO. Graphical abstract: (Figure presented.). © The Author(s), under exclusive licence to Springer-Verlag GmbH Germany, part of Springer Nature 2024.Öğe PREDICTION OF CARBON DI OXIDE AND OTHER EMISSIONS CHARACTERISTICS OF LOW CARBON BIOFUEL-HYDROGEN DUAL FUEL ENGINE - A MACHINE LEARNING APPROACH(International Association for Hydrogen Energy, IAHE, 2022) Bai, F.J.J.S.; Varuvel, E.G.The transportation sector is a major emitter of carbon dioxide emissions. It is a known fact that carbon dioxide is the cause of global warming which has resulted in extreme weather conditions as well as climate change. In this study a combination of different methods of expediting the CO2 emission from a single cylinder common rail direct injection (CRDI) engine has been explored. The methods include use of low carbon content biofuels (lemon peel oil (LPO) and camphor oil (CMO), inducing hydrogen in the intake manifold and zeolite based after-treatment system. The emissions were found to reduce even further and at full load condition the lowest CO2 (39.7% reduction) and smoke (49% reduction) emissions were observed with LPO blend and hydrogen induction. The NO emission with hydrogen induction increases for both the blends, however, it was seen that the zeolite-based treatment system was effective in reducing the emission as well. As compared to baseline diesel, the maximum reduction in NO emission was 23% at full load with LPO blend, hydrogen induction and after-treatment system. Unfortunately, a lot of experimental research in the engineering field takes a long time and costs a lot of money. The number of experimental trials can be minimized by applying predictions using the available experimental data. Machine learning approaches can aid in the development of rapid and reliable data-based models that can supplement a traditional physical model. The goal of this work is to investigate if a data-based model can help to predict engine emission characteristics including CO, NOX, Smoke, BTE, and HC more accurately. In machine learning, ensemble methods are strategies for creating numerous models and then combining them to obtain better results. In most cases, ensemble approaches provide more accurate results than a single model. In the present work, ensemble learning algorithms like XGBoost, LightGBM, CatBoost, Random Forest (RF) are used for the prediction of emissions. The brake power and BSEC are the input parameters to these algorithms from which CO, NOX, Smoke, BTE, and HC are predicted under various combination of additives. The CatBoost model has produced high accuracy predictions which was followed by XGBoost, RF and LightGBM models. The predicted and actual values are compared each other and the performance of the algorithms were analysed using the evaluation metrics like R-Square(R2), Mean Absolute Error (MAE), Mean Square Error (MSE) and Root Mean Square Error (RMSE). © 2022 Proceedings of WHEC 2022 - 23rd World Hydrogen Energy Conference: Bridging Continents by H2. All rights reserved.Öğe A study on the feasibility of bergamot peel oil-gasoline blends for spark-ignition engines(Elsevier, 2022) Vikneswaran, M.; Saravanan, C.G.; Manickam, M.; Sasikala, J.; Joseph Shobana Bai, Femilda Josephin; Pugazhendhi, A.; Varuvel, E.G.In this research, an ample attempt was made to make use of oil extracted from bergamot fruit peel, which can be regarded as a renewable energy source. A systematic experimental approach was adopted to evaluate the feasibility of bergamot peel oil (BGT) as a substitute for gasoline fuel in spark-ignition (SI) engine applications. The oil derived from the rinds of the bergamot fruit was blended in gasoline on a volume basis in the ratios of 10:90, 20:80, 30:70, and 40:60 and experimentally tested in a multi-point fuel injection (MPFI) installed SI engine. The fuel properties of the BGT and its blends were tested. Endoscopic visualization technique was used to analyze the spatial flame distribution on a crank angle basis for the gasoline and bergamot blends. Also, the performance, combustion, and emission characteristics of bergamot-gasoline blends were evaluated, and the results were compared with sole gasoline at various engine brake powers. The endoscopic results revealed that bergamot-gasoline blends exhibited higher flame spread than sole gasoline. The performance study revealed that the brake thermal efficiency and specific fuel consumption exhibited by bergamot-gasoline blends were almost equivalent to that of sole gasoline. The mean in-cylinder pressure was marginally higher, and peak pressure crank angle degree was slightly advanced for bergamot-gasoline blends in comparison to that of gasoline fuel. With an increasing concentration of BGT in the blend, the hydrocarbon (HC) and carbon monoxide (CO) emission decreased at the expense of nitrogen oxides (NOx). Furthermore, BGT exhibits a research octane number (RON) of 80 and a calorific value comparable to that of gasoline, making it a potential candidate for SI engines. From the outcome of this study, it can be concluded that BGT could be a promising alternate biofuel for the partial replacement of gasoline in SI engines. © 2022 Elsevier Ltd
