Faculty Publications
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Item Estimation of heat transfer coefficient and reference temperature in jet impingement using solution to inverse heat conduction problem(Pleiades journals, 2019) Kadam, A.R.; Hindasageri, V.; Kumar, G.N.The heat transfer estimation in case of impinging jets has been considered by mainly steady-state techniques. The present study reveals the transient technique to characterize the impinging jets. A solution to three-dimensional inverse heat conduction problem (IHCP) is used to estimate the unknown transient surface temperature distribution at the jet impinging side (front side) from known non-impingement side (backside) transient temperature distribution. Further to estimate front side heat flux distribution, the temperature gradient close to the front surface is computed by finite difference method, and then linearity between surface heat flux and corresponding surface temperature is utilized to find out heat transfer coefficient (HTC) and the reference temperature simultaneously. To validate and establish the present technique, numerical simulations are carried out in fluent. The numerically estimated back surface temperature data is used as input to the solution to IHCP. Hot as well as cold impinging jets are characterized with the help of this solution. Along with laminar jets, turbulent jets with varying Reynolds number are considered. The inversely estimated results are compared with numerically simulated data and match is within 1%. © Springer Nature Singapore Pte Ltd. 2019.Item Recent developments in finding laminar burning velocity by heat flux method: A review(Pleiades journals, 2019) Abhishek, A.P.; Kumar, G.N.This paper reviews the recent developments in heat flux method to determine the laminar burning velocity of a liquid or a gaseous fuel. Laminar burning velocity is an elementary property in designing the combustion chamber and turbulent combustion model and to validate kinetic simulation. There are numerous methods to find the laminar burning velocity such as Bunsen burner method, flat flame burner method, counterflow method, soap bubble technique, tube propagating technique, and heat flux method. In this paper, some of these methods are discussed in brief and recent developments of heat flux method have been elaborated, as this method is simple and accurate. To find out laminar adiabatic burning velocity, there are two requirements to be satisfied. First is the flame should be one-dimensional, thus flat and stretchless; second is adiabatic which means net heat exchange with the burner is zero. But, satisfying both these conditions at the same time is very difficult. The other methods have failed in satisfying both the conditions. However, heat flux method proved to satisfy these conditions. Results of laminar burning velocity using heat flux technique for methane–air have been compared with other methods of finding laminar burning velocity. © Springer Nature Singapore Pte Ltd. 2019.Item Analysis of Cyclic Variations and Combustion Behavior of Liquid Phase Hydrocarbons Under Uniform Axial and Radial Magnetic Fields(Springer Science and Business Media Deutschland GmbH, 2023) Oommen, L.P.; Kumar, G.N.The present study experimentally investigates the combustion characteristics of a multi-cylinder MPFI spark ignition engine fuelled by gasoline under uniform magnetic fields. Permanent magnets made of N38 grade NdFeB are used to magnetize the liquid phase hydrocarbons and the impact produced on combustion characteristics like in-cylinder pressure and net heat release rate are studied under different speeds and load conditions of the engine operation. Three different magnetic intensities (3200 G, 4800 G, and 6400 G) are employed in two different magnetization patterns (axial and radial) at an inbuilt ignition timing of 5 deg bTDC. Magnetic field assisted combustion is observed to enhance the performance characteristics of the engine, while simultaneously reducing the exhaust emissions to a significant level. A statistical analysis of cyclic fluctuations in magnetic field-assisted combustion is also made which shows a reduction in fluctuations (COV) with the application of each stage of ionization. The increase observed in peak pressures and heat release rates along throughout the combustion cycles with reduction in cyclic variations indicate that magnetic field-assisted combustion exhibits better combustion characteristics as compared to normal gasoline combustion. © 2023, The Author(s), under exclusive license to Springer Nature Singapore Pte Ltd.Item Experimental investigations of performance and emission characteristics of single cylinder CI engine fueled with different blends of jatropha biodiesel with Metal based additive.(Korean Society of Combustion, 2013) Kulkarni, A.; Patil, B.; Vijaykumara, M.; Kumar, G.N.The present investigation is focused on effect of CoCl2 as metal based additives on four stroke, single cylinder, air cooled direct injection diesel engine fuelled with various blends of jatropha biodiesel. Experiments were conducted to study performance and emission characteristics of CI engine operated at a constant speed of 1500 rpm at variable load from no load to full load in step of 25%. The Metal based additive (CoCl2) was added at a dosage of 50 μmol/L of biodiesel in a jatropha biodiesel-diesel blend. Experimental results revealed that, when compared with blends without additive, significant improvement in brake thermal efficiency was observed by 1.24% for B20 and 1.52% for B40. From emissions profile, HC was lowered such as 18.18% reduction was observed for B40 with additive at 50% load condition also, other blends showed reductions in the range of 10% to 16% at various load conditions.NOx found to be lowered in the range of 10-12% for blends with additive compared to plain blends. Hence, CoCl2 added at a dosage of 50 μmol/L is efficient in improving the performance and emission characteristics of jatropha biodiesel particularly for B20 and for B40. And they can be used as a suitable alternative to diesel fuel.Item Effect of Hydrogen Addition on Combustion and Emission Characteristics of High Speed Spark Ignition Engine- An Experimental Study(SAE International, 2015) Shivaprasad, K.V.; Chitragar, P.R.; Kumar, G.N.This article experimentally characterizes the combustion and emission parameters of a single cylinder high speed SI engine operating with different concentrations of hydrogen with gasoline fuel. For this purpose, the conventional carbureted high speed SI engine was modified into an electronically controllable engine, wherein ECU was used to control the injection timings and durations of gasoline. The experiments have been conducted for different engine speeds at various throttle positions. The experimental results demonstrated that engine brake power and brake thermal efficiency increased to certain extent and then decreases with the increase of hydrogen percentage in the fuel blend. The experimental results revealed that heat release and cylinder pressure increased with addition of hydrogen fraction till 20%. It also showed the reduction in HC and CO emissions in comparison with pure gasoline. The main drawback detected was higher NOx emissions due to the high combustion temperature. © © 2015 SAE International.Item An Experimental Study on Combustion and Emission Analysis of Four Cylinder 4-Stroke Gasoline Engine Using Pure Hydrogen and LPG at Idle Condition(Elsevier Ltd, 2016) Chitragar, P.R.; Shivaprasad, K.V.; Nayak, V.; Bedar, P.; Kumar, G.N.Fluctuation in oil prices and stricter exhaust emission norms were the main reasons wakening every researcher to search for suitable and feasible alternative fuels for automotive use. Among the available option gaseous fuels find their best position because of their compatible physical-chemical properties and ecofriendly nature than present fossil fuels. Hydrogen's combustion properties like high energy content, high heating value, wide range of flammability and low ignition energy with almost least toxic emissions are favorable to use in an IC engine as an alternative fuel. Liquid petroleum gas (LPG) has lower carbon content, higher calorific value, octane number and flame propagation speed will improve the emission results compared to gasoline fuel. This paper describes an experimental results carried out to evaluate the combustion and emission performance of a Maruti Suzuki make, spark ignited four cylinders, four stroke engines at idle condition by using pure hydrogen, LPG and gasoline. The engine was adjoined with Electronic Control Unit (ECU) assisting hydrogen and LPG injector system keeping gasoline line unchanged. Tests were carried out by using compressed hydrogen gas regulated by two stage pressure reduction from cylinder to atmospheric value and by using vaporizer pressure for LPG. For comparison engine was run first by gasoline and then by pure hydrogen and LPG. Study revealed that there was increment of 13% cylinder pressure for pure hydrogen and decrement of 4.5% cylinder pressure for LPG when compared to gasoline. The burn duration for pure hydrogen, LPG and gasoline were found to be increasing respectively which infers that hydrogen has very short combustion duration and gasoline higher. It was observed that toxic emissions like Carbon monoxide (CO), Hydrocarbons (HC) and Oxides of Nitrogen (NOx) were improved for pure hydrogen than LPG and gasoline. © 2016 The Authors.Item Performance Emission and Combustion Characteristics of CRDI Engine Operating on Jatropha Curcas Blend with EGR(Elsevier Ltd, 2018) Bedar, P.; Kumar, G.N.The present experimental study uses dual cylinder common rail direct injection (CRDI) engine fuelled by Jatropha curcas biodiesel blends produced through Transesterification process along with application of water cooled exhaust gas recirculation (EGR) rates. Performance, emissions and combustion properties of an engine at constant speed were measured and analysed. The improvement in brake thermal efficiency (BTE) along with reduction in carbon monoxide (CO), unburned hydrocarbons (UBHC) and smoke opacity were observed for the B20 biodiesel blend with a marginal increase in oxides of nitrogen (NOx). EGR application has reduced the NOx emissions and peak pressure inside the combustion chamber due to lower flame temperature. Combining B20 blend ratio with 15% EGR rate has the potential to achieve ultra-low NOx without affecting other type of diesel engine exhaust emissions by maintaining same efficiency level. © 2018 Elsevier Ltd.Item Transient heat transfer characterization of impinging hot / cold jets by analytical IHCP(Institute of Physics Publishing helen.craven@iop.org, 2018) Kadam, A.R.; Hindasageri, V.; Kumar, G.N.Unknown transient surface temperature and heat flux distribution at the impingement side (front side) is estimated from known temperature distribution at non-impingement side (back side) using analytical solution to three dimensional inverse heat conduction problem (IHCP). Back side input temperature data are obtained by running forward code in Fluent. Hot as well as cold impinging jets are characterized with the help of this solution. Laminar and turbulent jets at nozzle to plate spacing (Z/d) equal to 4 are considered. Hot gas at temperature 500 K and 3000 K is impinged on a 1 mm flat plate which considered initially at temperature 300 K in case of heating application. Whereas in cooling application, flat plate is initially assumed at temperature 673 K and isothermal air jet at 293 K is impinged on it. The temperature and heat flux estimation data by present technique is in very good agreement with the simulation data. © Published under licence by IOP Publishing Ltd.Item Designing of Digital Odometer Processing for Vehicles(Institute of Electrical and Electronics Engineers Inc., 2019) Jawale, M.; Hindoddi, A.; Patil, R.; Daigavane, P.; Kumar, G.N.; Dhanwate, S.Vehicle Odometer system, designed to measure the distance traveled and the instantaneous velocity of the vehicle. An Odometer display system includes a control unit connected to an Ignition Keyon Switch of a vehicle to obtain the accumulated mileage by accumulating a pulse signal produced according to the running of the vehicle. The control unit stores odometer data in an EEPROM. The control unit also reads the odometer data stored in the BBRAM when the ignition key on switch is operated. The Digital Odometer is designed using the MPC55XX automotive controller to improve reliability and overall performance. As per the Functional Requirement for a Digital Odometer, the control strategy is developed for Odometer Processing. Digital Odometer has high accuracy with better visualization with more functions with less cost. This paper is going to propose the Processing of Digital odometer with improved speed of operation. © 2019 IEEE.Item Thermal barrier coating for diesel engine application - A review(Elsevier Ltd, 2020) Godiganur, V.S.; Nayaka, S.; Kumar, G.N.In the current world scenario with the threat of global warming, diesel engines have to more efficient than ever to avoid the situation to be even worse. Thermal barrier coating (TBC) may be successful in making diesel engines more efficient. TBCs are proven to be performing well in gas turbines and used widely in that application. TBCs in a diesel engine are exposed to a slightly different environment in comparison with gas turbines. Different bond coat and top coat materials that can be used in relatively low-temperature application such as diesel engine. A simplified review is done on durability and reliability aspects like residual stress, thermal cycling performance, thermal conductivity, and thermal reflectance is done in this paper. © 2020 Elsevier Ltd. All rights reserved.