Faculty Publications
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Item Effect of exhaust gas recirculation (EGR) on diesel engine using Simarouba glauca biodiesel blends(Regional Energy Resources Information Center (RERIC) enreric@ait.ac.th, 2015) Bedar, P.; Pandey, J.K.; Kumar, G.N.This article deals with the usage of non-edible Simarouba glauca (paradise) oil as a biodiesel for single cylinder diesel engine with application of exhaust gas recirculation (EGR) rates. Biodiesel blends B10, B20 with EGR rates of 10%, 15%, and 20% are used for different load conditions. Parameters like brake thermal efficiency (BTE), nitrogen oxides (NOx), carbon monoxide (CO), hydrocarbons (HC) and smoke opacity were evaluated from the experimental study. The results show that Simarouba glauca biodiesel usage decreases HC, CO and smoke emissions with slight increase of NOx, also an improvement in the performance was observed for B10 blend. EGR rates 10% and 15% are beneficiated in terms of performance and emission but negative trend is observed for 20% EGR rate. On the whole it is concluded that a better trade-off between NOx and other emissions is attained with simultaneous application of EGR (15%) and biodiesel blend (B10) without compromising engine performance.Item Impact of changing compression ratio on engine characteristics of an SI engine fueled with equi-volume blend of methanol and gasoline(Elsevier Ltd, 2020) Nuthan Prasad, B.S.; Pandey, J.K.; Kumar, G.N.In the present investigation, experiments were conducted in wide open throttle condition (WOT) for different speed ranging from 1200 rpm to 1800 rpm at an interval of 200 on a single-cylinder four-stroke variable compression ratio (VCR) SI engine. The engine fueled with equi-volume blend of methanol/gasoline fuel, while 14° BTDC ignition timing is maintained for all three different compression ratios (8, 9 & 10). Increasing the compression ratio from CR8 to CR10 for the methanol/gasoline blend has improved combustion efficiency by increasing the peak pressure and net heat release value by 27.5% and 30% respectively at a speed of 1600 rpm. The performance results show a good agreement of improvisation of 25% increase in BTE, and BSFC reduction by 19% at compression ratio 10:1. At higher compression ratio 10:1, there was a significant decrease observed in CO and HC by 30–40%, and the same trend is observed at all speeds; however, NOx emission increased with the increasing CR. © 2019 Elsevier LtdItem Effect of hydrogen enrichment on performance, combustion, and emission of a methanol fueled SI engine(Elsevier Ltd, 2021) Nuthan Prasad, B.S.; Pandey, J.K.; Kumar, G.N.The study of potentially high rated alternative fuel (Methanol) for the IC engines is an exciting topic in the recent research advancement. However, the study of combination of methanol and hydrogen is considered to address both economic and environmental needs. Hydrogen with best combustion characteristics will compensate for the drawbacks of methanol as a fuel. In the present investigation hydrogen enrichment to methanol has shown a significant enhancement in performance and combustion; the overall emission has reduced substantially. The experiments for a different set of trials, including hydrogen enrichment ranging between 5% and 20% with 2.5% increment, the engine is operated with wide-open throttle (WOT) condition for different speeds. The increase in enrichment of hydrogen has shown a rise in BTE, BP, and a reduced BSEC value. The percentage increase in BTE is between 20 and 30%, and an increase in hydrogen beyond 12.5% would affect the volumetric efficiency, and thus performance declines after that. The exhaust emissions have a huge impact on hydrogen enrichment; CO, HC, and CO2 emission are reduced by 30–40%; however, an increase in cylinder temperature due to rapid combustion slightly increases the NOx emission. Thus hydrogen enriched methanol operating at higher compression ratio can improve the overall engine characteristics significantly. © 2021 Hydrogen Energy Publications LLCItem Consequences of ignition timing on a hydrogen-fueled engine at various equivalence ratio(Taylor and Francis Ltd., 2022) Pandey, J.K.; Gottigere Narayanappa, K.The energy crisis in the transportation sector directs researchers to look for renewable alternative energy sources. Among all available, hydrogen is one of the prominent contenders that can be renewed and available on a large scale and is carbon-free. The study suggests hydrogen is a better fuel for SI engines than CI engines. However, its feasibility still needs to be investigated. In the present experimental study, a hydrogen-fueled SI engine is tested for various equivalence ratios (ϕ) and ignition timing (IT) at a compression ratio (CR) of 14:1. The outcomes show that the brake thermal efficiency (BTE) increases by 1.07% with increasing ϕ, while a slightly retarded IT exhibits the best figure. There is an average 1.42% increase per ϕ from gasoline noticed at ϕ 0.6, which increased to 2.12% at ϕ 0.8. The cylinder pressure and net heat release rate improve and advance with retarding IT and increasing ϕ. The flame development period (CA10) continuously reduces with increasing ϕ by an average 1.93%/ϕ change and retarding IT by 2.17%/2°CA ignition retard, due to increased mass of hydrogen and increased cylinder temperature. While flame propagation period (CA10-90) reduces with increasing ϕ and reduces to a minimum with retarding IT and then increase. The maximum cylinder temperature (Tmax) and exhaust gas temperature (EGT) increase with increasing ϕ by 3.28% and 3.62%, respectively, while Tmax reduces with retarding IT, resulting in a reduction in NOx emission. The EGT increases with retarding IT. The NOx emissions increase with ϕ by an average of 4.72%; however, at higher ϕ = 0.8, the NOx emissions are 2.51% lower than gasoline for most of the retarded IT. At a retarded IT, hydrogen performs similarly to gasoline at moderate NOx emissions. The high CR helps reduce volumetric losses reflected in BTE, found above gasoline despite less fuel energy supplied than gasoline. Although NOx emissions are controlled by retarding IT, an efficiently controlling IT resulted in a severe drop in BTE. © 2022 Taylor & Francis Group, LLC.Item Effect of variable compression ratio and equivalence ratio on performance, combustion and emission of hydrogen port injection SI engine(Elsevier Ltd, 2022) Pandey, J.K.; Kumar, G.N.The present study includes an experimental investigation of the performance, combustion, and emission parameters of a hydrogen port fueled SI engine under wide-open throttle. The compression ratio (CR) is varied from 10 to 15, equivalence ratio (φ) from 0.4 to 1.0, and speed from 1400RPM to 1800RPM. The ignition timing is maintained at 20° before the top dead center. The brake thermal efficiency increases by nearly 10% from CR10 to CR15, and it also increased by 13.7% by changing φ from 0.4 to 0.9. Similarly, BP increases in the same fashion. The combustion enhances with an increase in peak pressure by increasing CR from 10 to 15 and φ from 0.4 to 0.9; however, φ 1.0 exhibits a negative trend. However, the NOX emission increases continuously with CR and φ, and so as the exhaust gas temperature. The carbon-based emissions are negligible, and volumetric efficiency decreases with φ and increases with CR. © 2021 Elsevier LtdItem Effect of parallel LPG fuelling in a methanol fuelled SI engine under variable compression ratio(Elsevier Ltd, 2022) Dinesh, M.H.; Pandey, J.K.; Kumar, G.N.In the present experimental study, five LPG fractions from 25% to 45% based on total energy are tested in a methanol fuelled SI engine at compression ratios (CR) varying from 12 to 15. Results are affirmative towards methanol/LPG dual fuel. The brake power, brake thermal efficiency, and volumetric efficiency are found to increase by 51%, 21.2%, and 13% respectively by changing from 25% LPG fraction at CR12 to 45% LPG fraction at CR15. The flame development period is found to decrease with CR and LPG, while the flame propagation period and total combustion duration are found to decrease with CR but increase with LPG. The maximum cylinder pressure and net heat release rate are found to increase by 101% and 27.8% respectively and advanced. CO emissions are found to decrease with CR while increase with LPG fraction. HC is found to decrease with LPG as well as CR. CO2 emissions are found to increase continuously with increasing LPG fractions and CR. The NOx emissions are also found to increase explicitly with LPG and CR, a net 209% increase in it is found 25% LPG at CR 12–45% LPG at CR15. © 2021 Elsevier LtdItem Effects of hydrogen assisted combustion of EBNOL IN SI engines under variable compression ratio and ignition timing(Elsevier Ltd, 2022) Pandey, J.K.; Kumar, G.N.Alcohols are oxygenated fuels, holding a good reputation among alternatives, but single alcohol does not possess all qualities. Besides, the high latent heat and low vapor pressure limit their uses in SI engines. Hence, an energy enhancing and combustion promoting fuel helps overcome the drawbacks, among all available hydrogen fits the race most. Hence, hydrogen-assisted combustion of equivolume blend of ethanol/butanol (ENBOL) is experimentally tested under various compression ratios (CR) (11–15), ignition timing (16°CA-24°CA BTDC) for three hydrogen fractions (5%–15%) at three speeds (1400RPM-1800RPM). The experimental outcome notices an increase in brake power (BP), brake thermal efficiency (BTE), peak pressure (Pmax), heat release rate (HRRmax), and NOx emissions with increasing CR and Hydrogen addition. The combustion duration, CO, and UBHC emissions reduce while CO2 emissions reduce with hydrogen; increasing CR notices a drop in CO2 at a much advanced or much-delayed ignition. Hydrogen improves combustion but reduces volumetric efficiency; increasing CR improves it, and hydrogen effect reduces with increasing CR. BP, BTE, and CA10-90 improve with retarding ignition from 24°CA, while CA10, Pmax, and HRRmax reduce continuously. UBHC and CO emissions increase while NOx reduces with retarding ignition. The ignition timing of 20°CA at CR15 and 15% hydrogen performed better than gasoline. © 2022 Elsevier LtdItem Study of performance, combustion, and NOx emission behavior of an SI engine fuelled with ammonia/hydrogen blends at various compression ratio(Elsevier Ltd, 2022) Dinesh, M.H.; Pandey, J.K.; Kumar, G.N.In the present paper, an experimental investigation has been performed under variable CR and 1400&1800RPM speed at a fixed spark timing of 24ºCA BTDC under wide-open throttle conditions. The hydrogen blending is performed based on energy fractions from 5% to 21% of the total fuel energy. With increasing compression ratio (CR), the flame development gets faster, and the flame propagation speed improves, leading to a short combustion period. Similarly, increasing hydrogen fraction improves combustion, resulting in a rapid rise in pressure and temperature. Despite a 13.64% decrease in volumetric efficiency from 5% to 21% hydrogen fraction at 1400 and 1800 RPM, BP and BTE increased by 16.89% and 33%, respectively. The slow-burning properties of NH3 extend the combustion period, resulting in a long-delayed burning period. As a result, the temperature of the low-hydrogen fraction of the exhaust gas is higher. As the hydrogen fraction and CR increase, this effect decreases, resulting in lower EGT. The hydrogen addition increases the peak temperature; therefore, NOx increases continuously with increasing hydrogen despite reducing ammonia. Ammonia is a key element used to reduce NOx from vehicles. A practical solution for controlling the NOx due to the ammonia/hydrogen blend is selective catalytic reduction (SCR). © 2022 Hydrogen Energy Publications LLCItem Study of biomethanol as sustainable replacement of Autogas at variable ignition timing(Elsevier Ltd, 2022) Pandey, J.K.; Dinesh, M.H.; Kumar, G.N.Bio-methanol has recently interested researchers looking for a suitable alternative due to its low carbon/hydrogen (C/H) ratio. Adding methanol to Autogas could thereby improve combustion while lowering emissions. In the present investigation, testing is conducted at a compression ratio of 14:1 on various fuel ratios (55/45 to 75/25 with a 5% change) of methanol/Autogas with ignition timing ranging from 28°CA bTDC to 14°CA bTDC. The results indicate improvements due to the addition of 65% methanol. Improved brake thermal efficiency (BTE) by 6.27%, peak pressure (Pmax) by 0.36%, heat release rate (HRRmax), peak temperature (Tmax) by 0.89%, and rise in exhaust gas temperature (EGT). Simultaneously, combustion duration, HC & CO emissions, and the coefficient of variations in indicated mean effective pressure (CoVIMEP) are reduced. With methanol, the volumetric efficiency (ηvol) improves continuously. Optimal ignition timing is shown to advance with increasing methanol concentration. With ignition retard, the flame development phase (CA10) decreases by 1.7%/2°CA ignition retard, whereas the flame propagation phase (CA10–90) decreases to a minimum and then increases. Due to combustion instability, ignition retard increases the Cyclic variation and CoVIMEP, while Pmax, HRRmax, Tmax, and BTE increase to a maximum and then drop. Ignition retard is an effective way of reducing NOx emissions, although CO and HC emissions increase significantly. Due to reduced carbon supply, carbon emissions are extremely low even at higher methanol concentrations than Autogas-rich fuel. NOx emissions are also extremely low (62.5 % of the ignition angle at 24°CA), revealing that a higher methanol ratio could be used with minimal risk of power loss. © 2022 The AuthorsItem Consequences of varying compression ratio and ignition timing on engine fueled with E-MEBANOL(SAGE Publications Ltd, 2023) Pandey, J.K.; Dinesh, M.H.; Gn, K.Alcohols are oxygenated renewable fuels responsible for low carbon emission and high H/C ratio. In the present study, a blend of methanol, ethanol, and n-butanol in equal proportion by volume (E-MEBANOL) is tested as a sustainable fuel for SI engines under variable compression ratio (CR) and ignition timing (SOI). The performance of the engine is found to improve by increasing CR as well as advancing the SOI, as the brake power (BP), brake thermal efficiency (BTE), and volumetric efficiency are found to increase by increasing CR to 15 from 11 at an advanced SOI of 24°CA before top dead center (BTDC) from 16°CA BTDC by 17.54%, 17.47%, and 10.53% respectively. Similarly, combustion is also enhanced with increasing CR and advancing SOI as the peak cylinder pressure (Pmax), and maximum net heat release rate (NHRmax) are found to increase by 60% and 27.64%, respectively, while positions of these peaks are advanced by 17°CA and 18°CA respectively by increasing CR from 11 to 15 and SOI advanced to 24°CA BTDC. The flame development period (CA10) increases with advancing SOI and decreases with increasing CR, while the flame development period (CA10-90) and total combustion duration decrease with both increasing CR and advancing SOI. The CO & HC emissions improve with increasing CR and advancing SOI, while NOx increases drastically, but EGT decreases continuously. © IMechE 2022.