Numerical study of plasma-assisted ignition and stabilisation of a supersonic hydrogen–air combustion in LAERTE facility by a quasi-DC gliding arc

Abstract This article presents three-dimensional numerical simulations of the plasma-assisted ignition and stabilisation of a supersonic hydrogen/air combustion in a model scramjet combustor (LAPCAT-II combustion chamber). The simulated conditions correspond to an altitude of 33 km and a flight Mach number of 5, i.e. an inlet temperature and pressure <mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML" overflow="scroll"> <mml:mrow> <mml:msub> <mml:mi>T</mml:mi> <mml:mi>i</mml:mi> </mml:msub> <mml:mo>=</mml:mo> <mml:mn>1400</mml:mn> </mml:mrow> </mml:math> K and <mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML" overflow="scroll"> <mml:mrow> <mml:msub> <mml:mi>P</mml:mi> <mml:mi>i</mml:mi> </mml:msub> <mml:mo>=</mml:mo> <mml:mn>4</mml:mn> </mml:mrow> </mml:math> bar. The gliding arc discharge is produced by a Plasma Injector Module (PIM). A macro-model is used to simulate the restrikes of the arc. The simulations couple the gliding arc of 5 A, a hydrogen injection flow with a mass flow rate of 1.5 g·s −1 , and the main air crossflow. The gliding arc preferentially restrikes on the right and left sides of the PIM, near the injector. The arc rapidly produces small combustion kernels. Despite the inhomogeneous distribution of the heat release, the arc is able to maintain the combustion.