Читать книгу Internal Combustion Engines - Allan T. Kirkpatrick - Страница 69

A single cylinder engine operates at rpm with a compression ratio , bore m, and stroke m. The cylinder wall heat transfer coefficient W/‐K, the cylinder wall temperature K, and the mass transfer parameter is . The initial cylinder pressure, , at bottom dead center is 1 bar, with a temperature at bottom dead center of 300 K. The heat addition, = 1190 J, and the combustion duration is constant at 40 degrees. Assume that the ideal gas specific heat ratio is 1.4.

1 What is displacement volume , the volume at bottom dead center, , and the dimensionless heat addition ?

2 Calculate the nondimensional parameters , and .

3 Plot the effect of changing the start of energy release from −50 to +20 atdc on the thermal efficiency and imep of the engine.