Experimental and Numerical Investigations on the Ignition of RBCC Gas-Oxygen/Kerosene Rocket Ejector

Bingyang Liu,Yaqun Qi,Guobiao Cai,Ping Jin,Yixin Ma,Yuanjun Zhang,Angelo Cervone

doi:10.1155/2021/7002104

Bingyang Liu, Yaqun Qi + Show 5 more

Open Access

https://doi.org/10.1155/2021/7002104

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Abstract

The rocket ejector refers to a core component of a rocket-based combined cycle (RBCC) engine. The ignition is of critical significance for rocket ejection. Reliable and stable ignition crucially determines the normal operation of the engine. In this paper, a thrust chamber with coaxial swirl injector for the RBCC rocket ejection was developed and tested. Gas oxygen (GOX) and kerosene acted as propellants. As revealed from the test results, the process of ignition pressurizing comprised four phases. The oxygen prefilling time before ignition slightly impacted the ignition time, whereas it affected the peak pressure of ignition. In a confined range, the peak pressure decreased as the prefilling time was extended. The ignition was simulated by building a numerical model, and the results well complied with the experimentally achieved results. The numerical model is capable of specifically indicating the position of the kernel of fire and the process of flame propagation. The simulation results reveal that the propellant could form a combustible condition within 4 ms. The kernel was 6 mm away from the injector, located at the oxygen and kerosene mixing interface and approaching the upper wall. The above results reflected the vital role of the central recirculation zone formed by the prefilled oxygen. The ignition energy was transported near the injector under the convection effect, which ignited the stoichiometric mixture, and the entire ignition could reach a stable state within 20 ms. The numerical model which was developed in this paper can help clarify the combustion mechanism.

Highlights

Along with low-cost reusable space transportation systems and hypersonic weapon technology continuous development, the rocket-based combined cycle (RBCC) engine is gradually recognized
Shi et al [8] performed an experimental study on ejector-to-ramjet mode transition in a divergent kerosene-fueled RBCC combustor with low total temperature inflow
The embedded rocket in the RBCC combustor was critical to the ejector-to-ramjet mode transition, and the ignition and flameholding functions of the hot rocket plume should be fully exploited in the combustion organization

Summary

Introduction

Along with low-cost reusable space transportation systems and hypersonic weapon technology continuous development, the rocket-based combined cycle (RBCC) engine is gradually recognized. An et al [6] investigated the effect of expansion fan on cavity flameholding in a rocket-based combined cycle combustor fueled by ethylene. Li et al [7] investigated the two-stage fuel injection performance of RBCC under scramjet mode using Reynolds-averaged Navier-Stokes-based CFD modeling. Shi et al [8] performed an experimental study on ejector-to-ramjet mode transition in a divergent kerosene-fueled RBCC combustor with low total temperature inflow. The embedded rocket in the RBCC combustor was critical to the ejector-to-ramjet mode transition, and the ignition and flameholding functions of the hot rocket plume should be fully exploited in the combustion organization

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