Validation of the computation of rocket nozzle admittances with linearized euler equations

R. Kathan; D. Morgenweck; R. Kaess; T. Sattelmayer

doi:10.1051/eucass/201304135

All issues

Volume 4 (2013)

10.1051/eucass/201304135

Abstract

Open Access

Issue		Volume 4, 2013 Progress in Propulsion Physics


Page(s)		135 - 148
Section		Chapter Two. Liquid and gelled propulsion
DOI		https://doi.org/10.1051/eucass/201304135
Published online		05 March 2013

Progress in Propulsion Physics 4 (2013) 135-148

Validation of the computation of rocket nozzle admittances with linearized euler equations

R. Kathan¹, D. Morgenweck¹, R. Kaess² and T. Sattelmayer¹

¹ Lehrstuhl fúr Thermodynamik, Technische Universität München 15 Boltzmannstraße, Garching 85748, Germany
² Astrium GmbH, Space Transportation, TP 24 München 81663, Germany

Abstract

High pressure fluctuations coupled with unsteady heat release can affect a rocket engine seriously. Especially when the oscillations match eigenmodes such as T1, T1L1 and T2, T2L1, the acoustic pressure amplitude can reach a critical level. This paper deals with the investigation of the nozzle admittance, which is an important value to characterize the influence of the nozzle on the pressure inside the combustion chamber. Two different nozzle geometries are investigated experimentally at high frequencies. A method to decouple the acoustic modes is presented. The results are compared against an existing theory and simulated data.