Contributions of Shear Coaxial Injectors to Liquid Rocket Motor Combustion Instabilities
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.
Document Details
- Document Type
- Technical Report
- Publication Date
- Oct 24, 1997
- Accession Number
- ADA331635
Entities
People
- Michael M. Micci
Organizations
- Pennsylvania State University