Browsing by Author "Gottekere Narayanappa, K."

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Effect of DEE added Karanja biodiesel fuel on the performance, combustion and emission characteristics of CI engine under variable injection timing and engine load
(Taylor and Francis Ltd., 2023) Wogasso Wodajo, A.; Yadav, A.K.; Gottekere Narayanappa, K.
The higher density and viscosity of biodiesel reduce the engine's performance due to poor atomisation. The present study aims to investigate the effect of DEE and injection time on engine characteristics fueled with KME-diesel blends. For this purpose, single cylinder CI engine is used. The injection timing is advanced and retarded by 2° from the base injection timing (27° bTDC), and the load is varied from 0% to 100%. The addition of DEE to the blends results in a reduction of density and viscosity. At 29° bTDC, the brake thermal efficiency for 5% DEE is increased by 3.1% compared to a blend without DEE at full load. For 5% DEE, compared to 27° bTDC, 29° bTDC reduces the HC and CO emission by 4.5% and 42.8%, respectively at full load. It is concluded that the 5% DEE operating at 29° bTDC improves the engine's performance with a small rise in NOX emission. Highlights: DEE added biodiesel blend has lower viscosity and density than biodiesel. 5% DEE addition in biodiesel blend at advanced injection timing improves BTE and reduces emission. Lower in-cylinder temperature is achieved due to higher latent heat of evaporation. The CO and HC emissions for B25DE5 at 29° bTDC are reduced by 4.5% and 42.8% than 27° bTDC at full load. At advanced injection timing NOX emission for 5% DEE addition increased by 2.7% than 27° bTDC. © 2022 Informa UK Limited, trading as Taylor & Francis Group.
Experimental analysis of a mini truck CRDI diesel engine fueled with n-Amyl alcohol/diesel blends with selective catalytic reduction (SCR) as a DeNOx technique under the influence of EGR
(Taylor and Francis Ltd., 2024) Santhosh, S.; Gottekere Narayanappa, K.
The current work aims to investigate the compatibility of n-Amyl alcohol in a mini-truck common rail direct injection (CRDI) compression ignition (CI) engine with exhaust gas recirculation (EGR) and selective catalytic reduction (SCR) as a DeNOx technique. The n-Amyl alcohol is a renewable biofuel it effectively mitigates the demand for fossil fuels and reduces greenhouse gas emission. Palladium and Rhodium coated SCR catalyst was used to reduce the nitrogen oxides (NOx) emission. For SCR of NOx ammonia was used as a reductant. From the experimental results, it was noted that with an increase in the percentage of alcohol in the blends, a slight drop in brake thermal efficiency (BTE) and higher brake specific energy consumption (BSEC) was observed. Both NOx and hydrocarbon (HC) emissions could be reduced with the use of n-Amyl alcohol and a combination of SCR and EGR techniques. The maximum reduction of NOx can be successfully achieved with the use of 40N60D (40% n-Amyl alcohol & 60% Diesel v/v) blend with SCR and 20% EGR at the slight cost of BTE. The engine can be successfully worked up to 40% of n-Amyl alcohol/diesel blends without causing any visible damage to the engine, with less NOx emissions. It is concluded that n-Amyl alcohol will be a sustainable next-generation biofuel for commercial vehicles. © 2020 Taylor & Francis Group, LLC.
Experimental and numerical investigation on the effect of turboprop engine exhaust gas impingement on pusher aircraft
(Walter de Gruyter GmbH, 2023) Vinay, C.A.; Gottekere Narayanappa, K.; Yepuri, Y.G.
Turboprop engines require an exhaust nozzle or stub to duct the engine exhaust flue gas outboard of the aircraft. The design of these exhaust stubs are dictated primarily by the aircraft's configuration. In pusher aircraft, the exhaust stubs are designed to minimize the exposure of the flue gases from the engine exhaust on the propeller blades and fuselage. A fluid-thermal-structure coupling analysis is performed to understand the thermal effects of the engine exhaust jet flow on the thermo-mechanical behavior of pusher configured light transport aircraft propeller and structure. The steady thermal flow field of the aircraft with forward and reverse thrust, in which propeller blade angle variations were analyzed for different aircraft speed. The present work investigates a three-dimensional analysis of flow around the nacelle-airframe and the effect of exhaust flue gas impingement on the propeller blade surface. Based on the insights from the numerical results, the designed exhaust duct was integrated on the aircraft and carried out ground static and flight testing for various flight operating conditions in which propeller blade and fuselage surface temperature were measured. Numerical and experimental results are compared and validated for certain flight conditions and found satisfactory. © 2023 De Gruyter. All rights reserved.