A New Experimental Method for the Investigation of Fuel Spray Evaporation

Abstract

A phenomenologic al experimental method for the investigation of fuel spray evaporation is introduced. The method is based on the measurement of pressure decrease resulting from spray evaporation in a closed vessel at high temperature and pressure. If certain physical and thermodynamic properties of the fuel are available, the method gives the average lifetime of the droplets and a mixing characteristic of the spray. If these properties are unavailable, the method can be employed to compare injector designs. A significant advantage of this technique is that it serves as an automatic integrator of all the governing parameters of spray evaporation. Ethyl alcohol and water sprays evaporating in nitrogen gas have been investigated successfully. The initial conditions of these experiments were 400 psig, 450 psig, and 500 psig chamber pressures and 700 F, 800 F, and 900 F chamber temperatures. Fuel injection rates were approximately 30 g/sec. 16-hole and 8-hole self impinging injector-plates were used. The lifetime of the sprays was found to vary between 144 and 550 msec. a b B