Eventos Anais de eventos
ENCIT 2022
19th Brazilian Congress of Thermal Sciences and Engineering
Combustion analysis of a new concept uniflow two stroke engine for experimental aircraft application
Submission Author:
Roberto Begnis Hausen , RS , Brazil
Co-Authors:
Roberto Begnis Hausen, Mario Martins, FELIPE BALBOM, Guilherme Zulian, Matheus Strapasson
Presenter: Roberto Begnis Hausen
doi://10.26678/ABCM.ENCIT2022.CIT22-0467
Abstract
Experimental aviation has been growing in several countries and the engines to equip these aircraft are in constant advances and modifications, aiming to increase power and reduce fuel consumption. In this context, the objective of this study is to present the performance characteristics of a new concept of two-stroke engine with Uniflow gas scavenging system, which has a much lower specific fuel consumption (BSFC) when compared to two-stroke engines with Cross or Loop Scavenging system, commonly used in this category of aircraft. Therefore, a one-dimensional simulation was performed in the GT-Power© software of the proposed arrangement operating in conditions similar to an aircraft operation, with 2 bar of supercharging boost and maximum engine speed of 3000rpm, evaluating combustion and performance parameters. In addition to the standard aviation gasoline (AvGas) with 100 octane fuel, the use of ethanol was also simulated, which, due to its low lower heating value, showed high specific fuel consumption. Using AvGas as fuel, the power achieved at this engine speed is very close to 23kW@3000rpm, generating maximum torque of 71,5N.m@2700 rpm. At cruising speed (between 2400 and 2700rpm) the BSFC varies between 255 to 277 g/kW.h, lower than two-stroke engines currently used for this purpose, which present values between 420 to 480 g/kW.h, also in the cruising operation range (between 5000 and 6000 rpm for standards two stroke engines). Being supercharged, its efficiency is also higher, reaching more than 30%. Due to its two-stroke cycle, the power density is high, with specific power of approximately 90kW/l. According to the simulations performed at this point, the engine proposal is suitable to equip an experimental aircraft, as the engine is physically compact, with low fuel consumption and with specific power higher than its direct competitors.
Keywords
two stroke engine, experimental aviation, uniflow scavenge, boosted, 1D Simularion
