Impingement of Liquid Fuel Sprays on Heated Walls.
Final rept. 1 Aug 82-10 Jul 85,
CARNEGIE-MELLON UNIV PITTSBURGH PA DEPT OF MECHANICAL ENGINEERING
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An experimental study was made of the structure of high speed Diesel jets. A constant volume chamber was constructed into which sprays of different liquids at a controlled pressure and duration can be injected. The chamber can be pressurized to a design pressure of 900 psi and heated to 750 F. An air operated pump provides liquid injection pressures up to 10,000 psi. Microphotographs of the spray showed the formation of a train of surface waves and the presence of liquid ligaments issuing from the main liquid jet in the radial direction. Discharge coefficients decreased with increasing injection pressure, indicating presence of cavitation in the nozzle. Injection of liquid into a coaxial stream of air with velocities up to 340 ms allowed determination of the constant A in the aerodynamic theory which represents the intensity of surface perturbations before any amplification by shear occurs. Results of an experiment conducted with liquids of different vapor pressure on 5 nozzles, indicate tha cavitation is a function of a nondimensional pressure parameter. Keywords Diesel fuel sprays Spray nozzles.
- Reciprocating and Rotating Engines