Prediction of Heat Release in a Quiescent Chamber Diesel Engine Allowing for Fuel/Air Mixing

Early work on heat release in diesel engines has generally been based upon the simple single-zone model which assumes uniform conditions throughout the combustion chamber. The quiescent chamber engine, lacking virgorous air movement, is most dependent upon air entrainment into the fuel sprays and the single-zone model has proved less successful than with other types of engines. A computer program based on a two-zone model using jet mixing has been developed to synthesize a cylinder pressure diagram and the results compared with data from a quiescent chamber engine over a range of conditions including off-design conditions of nozzle hole number and size and air supply. Allowance for the effect of hole size on atomization of the fuel was made, using published data, and good correlation was then obtained.