Faculty Publications
Permanent URI for this communityhttps://idr.nitk.ac.in/handle/123456789/18736
Publications by NITK Faculty
Browse
13 results
Search Results
Item Polymer Quenchants for Industrial Heat Treatment(CRC Press, 2016) Prabhu, K.; Nayak, V.; Rao, P.Flux During Quenching 732 25.12 Application of Polymeric Quenchants in Heat Treatment of Steels 734 25.13 Application of Polymeric Quenchants in Heat Treatment of Aluminum Alloys 736 25.14 Summary 738 References 739 during the quench process. Generally, a liquid quench medium is commonly used to facilitate/control the heat transfer during quenching. The most commonly used quenchants in industries worldwide is water followed by oils. On immersion quenching in these liquids, the metal experiences three typical stages of quenching: vapor stage, nucleate boiling stage, and the convective cooling stage. However, the severity of cooling and the duration of the stages in both classes are very much different. Water, because of its severe nature of cooling, provides ample, or exceeds, mechanical properties over that which is required. Moreover, in many circumstances, such as cooling of complex objects or high-alloyed steels, it causes undue distortion, residual stresses, and, in the most severe case, crack formation. Oils, by their very viscous nature, deliver lower cooling performance and reduces is the propensity towards distortion and cracking. The low quench severity of oils results in reduced properties. These limitations compelled the quenchant suppliers to develop polymer quench media that offer the benefit of both water and oils. © 2017 by Taylor and Francis Group, LLC.Item Performance and emission characteristics of a mpi engine fueled with Iso-Butanol/Gasoline blends(SAE International, 2014) Sakleshpur Nagaraja, S.; Ravi, V.; Raviteja, R.; Nayak, V.A numerical and experimental study on performance and emission characteristics of four-stroke, four-cylinder Multi Point Injection (MPI) engine operating on iso-butanol/gasoline blends was carried out. The study aims at extending the widely used Wiebe function to combustion modeling of alternate fuels. Quasi one-dimensional simulation and experiments were carried out for different blends of iso-butanol and gasoline (0% (pure gasoline), 10% (IB10), 20% (IB20), 30% (IB30), by volume of iso-butanol) at wide open throttle (WOT) condition for five engine speeds in the range of 2000 to 4000 rpm. The computational and experimental results complement each other validating the proposed extension. BSFC of the blends initially drops for IB10 and later rises with increase in concentration of iso-butanol. Compared to gasoline, the blends lead to considerable decrease in the amount of unburned hydrocarbons (HC) and no change of carbon monoxide (CO). However, there is considerable increase in the amount of oxides of nitrogen (NOx). Copyright © 2014 SAE International.Item Experimental analysis of cardanol biofuel as an alternative fuel for diesel engines with air-side oxygen enrichment(Trans Tech Publications Ltd ttp@transtec.ch, 2014) Dinesha, P.; Nayak, V.; Kumar, D.; Mohanan, P.The present study investigates the effect of air-side oxygen concentration enrichment on the performance and emission of a single cylinder diesel engine using a bio-fuel blend as fuel. In this study, a natural phenolic compound, namely, cardanol is selected as the bio-fuel, which is obtained from the shell of cashew nut after purification. A blend of B10M10 (10% cardanol +10% methanol + 80% diesel by volume) is prepared and tested in the engine at various loading conditions. The experiments are carried out at atmospheric oxygen condition and an increment of 3, 5, and 7% of atmospheric oxygen concentration by weight. There is a drastic reduction in HC, CO, and smoke except for NOx emission. The level of NOx emission increases as the oxygen concentration in the intake air is increased. The performance characteristic will increase as the oxygen concentration increases, and higher brake thermal efficiency is obtained for B10M10 at 7% oxygen concentration. B10M10 with 7% oxygen enrichment gives better results, similar to diesel, except for NOx emission. © (2014) Trans Tech Publications, Switzerland.Item Emission and Performance Enhancement of Multi-Cylinder SI Engine Fuelled with LPG and Vaporized Water Methanol Induction(SAE International, 2014) Patil, B.; Nayak, V.; Padmanabha, M.This work aims study on the method of NOx reduction and performance enhancement by analysis of MPFI multi-cylinder gasoline engine running on LPG using the gas injection system and vaporized water-methanol induction to the intake manifold. For the generation of vaporized water-methanol, heat from the exhaust gas has been used. Different percentages of water- methanol by mass basis were used with variable engine speed ranging from 2000 to 4500 RPM. The outcomes indicated that as the percentage water-methanol induction level of the engine increased, there is a slight increase in percentage of useful work, while the NOx decreased drastically about 47%. Additionally, the engine brake thermal efficiency gains. The mean gain in the brake thermal efficiency for a 20% water methanol with LPG is approximately 1.5% over the use of LPG without water-methanol induction. © © 2014 SAE International.Item Performance and emission characteristics of LPG-Gasoline dual fuel on a multi-cylinder MPFI gasoline engine(Combustion Institute, 2015) Nayak, V.; Shankar, K.S.; Dinesha, P.; Mohanan, P.The present research experimentally investigates the performance and emission characteristics of LPG-Gasoline dual fuel on a gasoline engine. The engine setup consists of four stroke, four cylinder, water cooled MPFI engine with eddy current type loading unit. Experiments have been conducted with different LPG-Gasoline ratio (0%, 25%, 50%, 75%, and 100%) by mass and different speeds from 2000 to 4500 rpm in steps of 500 rpm at full load condition. From experimental investigation it is found that with the 50% usage of LPG, increases the brake thermal efficiency and volumetric efficiency when compared to gasoline for speed range of 2000 rpm to 4000 rpm. LPG will have much lower CO and HC emissions when compared to gasoline. This is a positive effect on environment. But for other LPG-gasoline ratio these emissions going to increases when compared to LPG but it is well below when compared to gasoline for all speeds. NOx emission is more for LPG almost 4 times that of gasoline for all speed conditions. For other LPG-gasoline ratio NOx emission is lower.Item Impact of injection timing on the performance and emission characteristics of a diesel engine fueled with cardanol blends(Combustion Institute, 2015) Dinesha, P.; Nayak, V.; Mohanan, P.The present study investigates the effects of fuel injection timing (IT) on the performance and emission characteristics of a four stroke, single cylinder direct injection water cooled diesel engine when fueled with the blend of cardanol bio-fuel blends namely B10M10, B20M10 and B30M10. Tests have been conducted with an engine speed of 1500 rpm, fixed compression ratio 17.5:1, at full load condition and 220 bar injection pressure (IP). The performance and emission characteristics are studied at three different ITs. The fuel IT is varied by retarding 2 deg. and advancing 2 deg. with respect to 27.5 deg. bTDC and the tests are performed at 25.5, 27.5, and 29.5 deg. bTDC ITs. At the advanced IT, BSEC decreased as early start of fuel injection ensures more complete combustion owing to improved reaction between fuel and oxygen. Considerable reduction in CO, HC, and smoke emissions are achieved, while NOx emission showed an increasing trend with 29.5 deg. IT and 220 bar IP. The results of the present investigation of cardanol bio-fuel blends show slight variation in performance, combustion, and emission characteristics between B10M10 and B20M10 compared to B30M10 blend at 29.5 deg. bTDC advanced IT and 220 bar IP.Item Combustion Characteristics and Cyclic Variation of a LPG Fuelled MPFI Four Cylinder Gasoline Engine(Elsevier Ltd, 2016) Nayak, V.; Rashmi, G.S.; Chitragar, P.R.; Mohanan, P.Present study deals with to investigate the effect of dual mode of operation on combustion characteristics of engine and cyclic variation in a modified multi-cylinder SI engine. Experiments will be conducted with baseline gasoline and later with dual fuel mode of experiments i.e., gasoline with LPG with different ratios (25%, 50%, 75% and 100% of LPG by mass). Experiment will be carried out with varying speed from 2000 rpm to 4500 rpm in steps of 500 rpm at full load condition with factory set static ignition timing of 5 deg. bTDC to investigate combustion characteristics and cyclic variations. Results revealed that as the LPG percentage increases the peak pressure also increases and it is maximum for 100% LPG for all the speed. At 4500 rpm the percentage increase in peak pressure is 20% for 100% LPG, 9% for 25%LPG, 3% for 50%LPG, 1% for 75%LPG when compared to gasoline at full load. This increase in peak pressure will indicate the LPG will give better combustion properties compared to that of gasoline. Compared to peak pressure, the variation in cycle to cycle for IMEP is less.Net heart release rate shows that gasoline will give the more heat release compare to all other fuels, but LPG will release the heat little earlier than gasoline. Since peak pressure is near to TDC for LPG which results in NHRR to occur earlier than gasoline. Final outcome of the research is LPG will have better combustion properties compared to gasoline but cyclic fluctuations are more for LPG. © 2016 The Authors.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 Precision Agriculture Using IOT Technology with a Case Study of Coffee Beans Production(Springer Science and Business Media Deutschland GmbH, 2025) Pawar, S.; Samaga, B.L.R.; Pandit, K.; Nayak, V.; Geetha, V.; Thinakaran, R.World population is rapidly increasing which requires similar increase in food production. Agriculture is playing an important role in the world economy. Nowadays precision agriculture is the best method to be practiced by the farmers. Sensors, communication technology, and data analysis are building blocks of smart farming in precision agriculture process. This paper is focused on a survey of precision agriculture using IOT and details about various sensors used with a case study of Coffee beans production in Coffee estate. Various sensors used in pre-production, production, and post-production of coffee beans are discussed. This paper also addresses the need of communication technology and its ranges for suitability of smart farming, besides a review is conducted on applications of IOT in various tasks of precision agriculture. © The Author(s), under exclusive license to Springer Nature Singapore Pte Ltd. 2025.Item Effect of oxygen enrichment on the performance, combustion, and emission of single cylinder stationary CI engine fueled with cardanol diesel blends(Korean Society of Mechanical Engineers, 2014) Dinesha, P.; Nayak, V.; Mohanan, P.We investigated the effect of intake air enrichment on the performance, combustion, and emission characteristics of a single cylinder direct-injection stationary diesel engine fueled with non- edible alternative fuel, namely, cardanol - diesel - methanol blend (B20M10). The results were compared with baseline diesel operations under standard operating conditions. The bio-fuel blend B20M10 (20% cardanol, 10% Methanol, and 70% diesel) was used as fuel and the combustion, performance, and emission characteristics were investigated by oxygen enriching of intake air with 3, 5, and 7 percentage by weight. With the increase of intake air oxygen concentration, CO, HC, and smoke were found to be decreased. But BTE and NOx emission were considerably increased. The blended fuel B20M10 with 7% oxygen enrichment of intake air was compared with diesel operation. The results show a 0.5% lesser BTE, 28% more NOx emission at full load condition. There is not much variation of smoke emission to be noticed for this fuel combination compared to diesel. © 2014 The Korean Society of Mechanical Engineers and Springer-Verlag Berlin Heidelberg.