An Experimental and Analytical Study of Engine Fuel Spray Trajectories

An analytical spray model is described which can be used to calculate the penetration and trajectory of a spray in an engine combustion chamber with air swirl. The model consists of integral continuity and momentum equations written for a steady-state gas jet. The model contains adjustable entrainment and drag parameters evaluated from experimental data.

A special single-cylinder, see-through engine and a schlieren optical system were used to study transient liquid fuel sprays under varied conditions. These experimental observations were used to determine appropriate values for the adjustable parameters in the spray model. Comparisons between model calculations and the experimentally observed sprays are presented for a wide range of conditions.