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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 Combustion analysis of higher order alcohols blended gasoline in a spark ignition engine using endoscopic visualization technique(Elsevier Ltd, 2022) Vikneswaran, M.; Saravanan, C.G.; Sasikala, J.; Ramesh, P.; Varuvel, Edwin GeoThe experimental study was carried out on the port fuel injection system installed spark-ignition engine fuelled by 1.5%, 3%, and 5% higher order alcohol such as 1-hexanol and 2-heptanol blended gasoline. In this study, the endoscopic combustion visualization technique was employed to compare and analyze the changes observed in the spatial flame characteristics between the alcohol blends and sole gasoline. The Correlated Colour Temperature (CCT) method was used to predict the flame temperature distribution from the captured flame images. Also, the effect of blending alcohols on engine combustion, performance, and emission characteristics was studied. The endoscopic results revealed that the flame spread region with respect to different CA positions increases with the alcohol blending ratio in the sole gasoline at the early and middle stages of the combustion. Further, the engine characteristics study revealed that 5% hexanol and heptanol blends gave a brake thermal efficiency of 25.8% and 25.7%, respectively, which were higher than sole gasoline, having 24.8% at full load. In addition, it was observed that the early start of combustion (SoC) and a faster burn rate associated with alcohol blends raise the cylinder pressure and heat release rates (HRRs) and thereby result in higher peak pressure and HRR with slight advancement in the CA position. At 8 kW, the CO and HC emission of 5% 1-hexanol and 2-heptanol blends was decreased by about 10.3% and 13.7%, and 9.5% and 8%, respectively, and NO emission decreased slightly with a rise in alcohol concentration in the mix when compared to gasoline. © 2022 Elsevier LtdÖğe Effect of hydrogen on compression-ignition (CI) engine fueled with vegetable oil/biodiesel from various feedstocks: A review(Elsevier Ltd., 2022) Thiyagarajan, S.; Varuvel, EdwinGeo; Karthickeyan, V.; Sonthalia, Ankit; Kumar, Gopalakrishnan; Saravanan, C.G.; Dhinesh, B.; Pugazhendhi, ArivalaganCompression ignition (CI) engines used in the transportation sector operates on fossil diesel and is one of the biggest causes of air pollution. Numerous studies were carried out over last two decades to substitute the fossil diesel with biofuels so that the net carbon dioxide (CO2) emission can be minimized. However, the engine performance with these fuel was sub-standard and there were many long-term issues. Therefore, many researchers inducted hydrogen along with the biofuels. The present study gives an outlook on the effect of hydrogen addition with biodiesel/vegetable oil from various sources in CI engine. Engine parameters (brake thermal efficiency, brake specific fuel consumption), combustion parameters (in-cylinder pressure and heat release rate) and emission parameters (unburned hydrocarbon (HC), carbon monoxide (CO), oxides of nitrogen (NOx) and smoke emissions) were evaluated in detail. The results show that hydrogen induction in general improves the engine performance as compared to biodiesel/vegetable oil but it is similar/lower than diesel. Except NOx emissions all other emissions showed a decreasing trend with hydrogen addition. To counter this effect numerous after-treatment systems like selective catalytic reduction (SCR), exhaust gas recirculation (EGR), selective non-catalytic reduction system (SNCR) and non-selective catalytic reduction system (NSCR) were proposed by researchers which were also studied in this review.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 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 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