Accession Number : ADA331635

Title :   Contributions of Shear Coaxial Injectors to Liquid Rocket Motor Combustion Instabilities

Descriptive Note : Final rept. 1 Mar 95-30 Jun 97

Corporate Author : PENNSYLVANIA STATE UNIV UNIVERSITY PARK DEPT OF AEROSPACE ENGINEERING

Personal Author(s) : Micci, Michael M.

PDF Url : ADA331635

Report Date : 24 OCT 1997

Pagination or Media Count : 12

Abstract : Acoustic oscillations were induced in a subscale liquid rocket engine that burned liquid oxygen and gaseous hydrogen as propellants. The oscillations in the chamber were forced by a rotating gear just downstream of the nozzle throat. High frequency data were acquired for pressure and velocity via a pressure transducer and a magnetic flowmeter. The magnetic flowmeter obtains the acoustic gas velocity by measuring the voltage induced by the ionized combustion products moving through an externally imposed magnetic field. A cross correlation was performed on the velocity and pressure signals to determine the amplitude and phase difference of the two signals A linearized one-dimensional acoustic model was developed to simulate the mean and unsteady flow within the chamber with mass and energy addition. The phase difference between unsteady pressure and velocity was determined from the model and fit to match the phase difference measured by the experiments. The points where the modeled and experimental phase differences agreed determined the real part of the propellant evaporation and combustion pressure and velocity coupled response functions.

Descriptors :   *LIQUID PROPELLANT ROCKET ENGINES, *COMBUSTION STABILITY, MAGNETIC FIELDS, SCALE MODELS, PRESSURE TRANSDUCERS, UNSTEADY FLOW, ACOUSTIC VELOCITY, FLOWMETERS, NOZZLE THROATS, CROSS CORRELATION, LIQUID OXYGEN, ROCKET EXHAUST.

Subject Categories : Combustion and Ignition
      Liquid Propellant Rocket Engines

Distribution Statement : APPROVED FOR PUBLIC RELEASE