A Study on a Vitiated Air Heater for a Direct-Connect Scramjet Combustor and Preliminary Test on the Scramjet Combustor Ignition

Abstract

Vitiation air heater (VAH) combustion characteristics for a direct-connect scramjet combustor (DCSC) were experimentally studied. The VAH consists of a head, modular chamber, and circular-to-rectangular shape transition (CRST) nozzle. The CRST nozzle transforms the circular cross-sectioned rocket-type VAH into a rectangular cross-sectioned scramjet combustor. The CRST nozzle exit Mach numbers at the top, middle, and bottom were measured using a tungsten wedge. The oblique shock formed by the wedge was captured using Schlieren visualization and recorded with a high-speed camera. The θ-β-M relation showed that the exit Mach number was 2.04 ± 0.04 with a chamber pressure of 1.685 ± 0.07 MPa. With the VAH design point verified, preliminary scramjet combustor ignition tests were conducted. As the fuel was not auto-ignited by the vitiated air, the forced ignition method, in which VAH ignition flame ignites the scramjet fuel, was used. The Schlieren images showed that a cavity shear layer combustion mode was formed and also showed that the forced ignition method could be used as a reference model for the ignitor-ignition method.

Numerical Investigation of Combustion Mechanism with Multi-Position Injection in a Dual-Mode Combustor

“…Currently, the cavity flame-holding structure has become one of the most common flame stabilization structures in scramjet combustion chambers. In addition to the cavity, baffles and rear steps are also commonly used flame stabilization structures in scramjet combustion chambers [6,7].…”

Large Eddy Simulation and Dynamic Mode Decomposition of Supersonic Combustion Instability in a Strut-Based Scramjet Combustor

“…Supersonic combustion is an important phenomenon in hypersonic air-breathing propulsion systems, and corresponding research has made great progress in the past decades [1,2]. Supersonic combustion in cavity-based combustors [3][4][5][6][7][8][9][10], strut-based combustors [11][12][13][14][15][16][17][18], and mixing layers [19,20] have all been investigated in detail. At present, unsteady supersonic combustion has become an issue of great concern in the field of supersonic combustion.…”