Slag and Thermal Environment of a Spinning Rocket Motor
Abstract
It has been demonstrated that an increase in radial and/or axial acceleration results in an increase in the amount of slag accumulated in the chamber of a motor with a submerged nozzle design. The slag is composed of aluminum and alumina residue from the combustion of aluminized solid propellants. The presence of slag in the chamber influences motor burnout weight, soak-out thermal environment, residual thrust, and motor performance. An excessive amount of slag in the chamber also could affect mission success. This report studies the effect of slag in the chamber on the motor case thermal environment of a spinning rocket motor. Very good agreement between analysis results and ground test data is obtained for motor case temperature histories throughout the motor firing and heat soak period of the spinning payload assist module (Star-48) qualification motors. In the area in which the insulation is exposed to combustion products during motor firing, the insulation erosion rate is a function of motor spinning rate. During heat soak, the slag mass is considered to be the single parameter that influences the thermal environment of a spinning rocket motor. Available data from a flight motor are analyzed and compared with the analysis results. The thermal environment for the PAM-S/ulysses flight motor is predicted. For a spinning flight motor, the analysis reveals that the insulation erosion rate and the amount of slag in the chamber of a spinning flight motor can be assessed or sensed from monitoring the temperature history on the outside surface of the motor case.
Document Details
- Document Type
- Technical Report
- Publication Date
- May 01, 1991
- Accession Number
- ADA238557
Entities
People
- I-shih Chang
Organizations
- The Aerospace Corporation