The Influence of Ambient Conditions on Compression Ignition Engine performance: (Experimental Study)

In I.C. engines, the variation of temperature and relative humidity for intake air play a paramount role in the engine performance therefore, these parameters were investigated experimentally to study and improve their design and operations. The performance of diesel engines can be expressed in terms of five variables (Brake specific fuel consumption (BSFC), Exhaust temperature (Tex), Air/Fuel ratio (A/F), Brake thermal efficiency (Zbth) and Mechanical efficiency (Zm)). A four-stroke diesel engine type (TD212) and capacity of 232 cc was utilized as the test engine. The inlet air was acclimated to required humidity and temperature values by using a humidifier before entering the inlet port of the engine. All the tests were achieved at constant speed of (1600 rpm) with the variation of loads from (2-10 N.m). The results showed that the A/F ratio, mechanical efficiency and brake thermal efficiency decrease, while the BSFC and Tex increase with increasing of both I.A.T. and RH of the inlet air. Also, at constant values of I.A.T and RH of inlet air, the results show increasing of Tex, brake thermal efficiency, and mechanical efficiency values with increasing engine loads while increasing the BSFC and A/F ratio with decreasing engine loads.