Nozzle Acoustic Dynamics and Stability Modeling
| Autor: | Paul W. Gloyer, Jonathan French, Gary Flandro, Eric J. Jacob |
|---|---|
| Rok vydání: | 2011 |
| Předmět: |
Propellant
Engineering business.industry Mechanical Engineering Nozzle Aerospace Engineering Mechanics Structural engineering Combustion Vortex Chamber pressure Physics::Fluid Dynamics symbols.namesake Fuel Technology Mach number Space and Planetary Science symbols Potential flow Particle velocity business |
| Zdroj: | Journal of Propulsion and Power. 27:1266-1275 |
| ISSN: | 1533-3876 0748-4658 |
| DOI: | 10.2514/1.b34239 |
| Popis: | In the analysis of rocket combustion stability, there are various sources and sinks of unsteady energy, ranging from propellant response to the interaction of the flow with vortices. As stability models are improved, additional fidelity is required in previously adequate models to reduce the error bandwidth. In this paper, we present a new technique for obtaining the linear nozzle damping exponent and compare it with a historically accepted method. Nozzle damping allows rocket motors and engines to literally exhaust unsteady energy from the interior, and an improved understanding of this process both improves our ability to predict overall stability and design rockets for improved stability. Previous techniques focused on computing the admittance or response of a nozzle to an incident wave, and encapsulating the average wave reflection as a simple function of frequency. In contrast, in the approach presented herein, the combined chamber-nozzle acoustic modes are computed, taking into account the chamber’s steady flow field influence on the acoustics throughout the motor or engine. The flux of unsteady energy through the nozzle plane is computed to derive the nozzle damping exponent. Three sample motors/engines are evaluated to investigate the characteristics of varying length to diameter ratio and to examine the influence of nozzle shape using regular and submerged nozzles. |
| Databáze: | OpenAIRE |
| Externí odkaz: |
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