Accession Number : ADA299059

Title :   Liquid Stability Mechanisms Program.

Descriptive Note : Final rept. Dec 89-May 93,

Corporate Author : PRATT AND WHITNEY WEST PALM BEACH FL GOVERNMENT ENGINES AND SPACE PROPULSION

Personal Author(s) : Peterson, Eric L. ; Evans, Tyler T. ; Cox, George B., Jr.

PDF Url : ADA299059

Report Date : AUG 1995

Pagination or Media Count : 281

Abstract : The processes participating in liquid rocket engine high frequency combustion instability are not well understood. The Liquid Stability Mechanisms (LSM) program investigated the potential, fundamental mechanisms of vaporization and secondary atomization. Using state-of-the-art diagnostic techniques, the vaporization rate of a droplet exposed to an acoustic perturbation was measured; the results indicate that the transient vaporization response is greatly affected by a pressure pulse. A multiphase, continuous injection droplet vaporization model was used to analytically predict droplet vaporization under oscillatory conditions. These results also indicate that the vaporization response is strongly affected by pressure waves and is capable of supplying enough energy to support an ordered oscillation in the combustion chamber. Shadowgraphic cinematography was employed to study the secondary atomization process in a newly built, high pressure shock tube. Preliminary results were obtained of droplet breakup under Reynolds number and liquid to gas density ratio conditions that match those seen under supercritical conditions were also obtained: these data show a process that differs from typical results at low pressure.

Descriptors :   *SUPERCRITICAL FLOW, *COMBUSTION STABILITY, *LIQUID ROCKET PROPELLANTS, INJECTION, RATIOS, STATE OF THE ART, HIGH PRESSURE, LASER APPLICATIONS, PULSES, DROPS, COMBUSTION CHAMBERS, DIAGNOSIS(GENERAL), PHOTOGRAPHIC ANALYSIS, PERTURBATIONS, OSCILLATION, REYNOLDS NUMBER, VAPORIZATION, SHOCK TUBES, SPARK SHADOWGRAPH PHOTOGRAPHY, ATOMIZATION.

Subject Categories : Combustion and Ignition
      Liquid Rocket Propellants

Distribution Statement : APPROVED FOR PUBLIC RELEASE