Numerical Modeling of Single-Pulse Gasdynamics and Performance of Pulse Detonation Rocket Engines

Abstract

Pulse detonation rocket engines (PDREs) offer potential performance improvements over conventional designs bu tr epresent a challenging modeling task. A quasi-one-dimensional, finite rate chemistry computational fluid dynamics model for PDREs is described and implemented. Four different PDRE geometries are evaluated in this work: a baseline detonation tube, a detonation tube with a straight extension, and a detonation tube with two types of converging/diverging (CD) nozzles. The effect of extension length and CD nozzle area ratio on the single-pulse gasdynamics and performance of a PDRE is studied over a wide range of blowdown pressure ratios (1‐1000). The results indicate that a CD nozzle is generally more effective than a straight extension in improving PDRE performance, particularly at higher pressure ratios. Additionally, the results show that the blowdown process of the CD nozzle systems could be beneficially cut off well before the pressure at the endwall reaches the ambient value. The single-pulse performance results are also compared to some recent experimental measurements as well as a steady-state rocket system using similar modeling assumptions.