Scale Effects on Solid Rocket Combustion Instability Behaviour

Abstract

Abstract:The ability to understand and predict the expected internal behaviour of a given solid-propellant rocket motor under transient conditions is important. Research towards predicting and quantifying undesirable transient axial combustion instability symptoms necessitates a comprehensive numerical model for internal ballistic simulation under dynamic flow and combustion conditions. A numerical model incorporating pertinent elements, such as a representative transient, frequency-dependent combustion response to pressure wave activity above the burning propellant surface, is applied to the investigation of scale effects (motor size, i.e., grain length and internal port diameter) on influencing instability-related behaviour in a cylindrical-grain motor. The results of this investigation reveal that the motor's size has a significant influence on transient pressure wave magnitude and structure, and on the appearance and magnitude of an associated base pressure rise.

Theoretical, Numerical and Experimental Investigation of Secondary Injection with a Novel Pyrogenic Pulser

“…To understand the behavior of solid rocket motors, it is better to solve the internal ballistics under transient conditions (Greatrix, 2011). Assumptions for the pulser and motor performance are 1) mass flow rate accumulation is taken to account; 2) burning surfaces ignite uniformly; 3) pressure varies with time but temperature is constant; 4) burning rate follows the relation ̇= ( ) (Seifollahzadeh & Aminian, 2014); 5) isentropic, one-dimensional flow in exhausts; 6) ideal gases, ⁄ = ℜ (Rousseau, 2011).…”

Analytical model for the prediction of pulsations in a cold-gas scale-model of a Solid Rocket Motor

“…Solid Rocket Motors (SRMs) can display strong acoustic oscillations [1][2][3]. For small engines these are often driven by a coupling between the combustion and acoustic standing waves in the engine [4,5]. In large SRMs the oscillations can be sustained by coupling between vortex shedding and acoustic standing waves [6,7].…”

Thermo-Structural Response Caused by Structure Gap and Gap Design for Solid Rocket Motor Nozzles

“…Normally, the temperatures can be 3000 K or higher and the pressure may reach about 10 MPa or higher for some special motor devices, especially those equipped with modern propellants that have better performance [4,5]. What is more, the temperatures and pressures of the gas are becoming higher and higher due to the increasing performance demands of SRMs.…”