Large-eddy simulation of a plane reacting jet transversely injected into supersonic turbulent channel flow

A plane, chemically reacting jet of fuel injected through a narrow spanwise slot into supersonic and fully turbulent air flow in a channel with isothermal, parallel walls is investigated using a semi-implicit large-eddy simulation technique. It is based on a variant of the approximate deconvolution method (ADM) proposed by Mathew et al. (2003; An explicit filtering method for LES of compressible flows. Physics of Fluids, 15 (8), 2279-2289) and on explicit modelling of the filtered heat release term. The fuel jet consists of a mixture of H2 and N2, the mass fractions being YH2=0.016875 and YN2=0.983125, respectively. Chemical reaction of H2 and O2 to water is modelled as an infinitely fast, irreversible one-step reaction. The composition is described by a mixture fraction evolving according to a transport equation for a passive scalar, which is solved along with the compressible Navier-Stokes equations. A ratio of slot width to channel height of h2/h1=1/32 characterises the geometric configuration. Spatial derivatives are computed using a tridiagonal finite-difference scheme of sixth order of accuracy given by Lele (1992; Compact finite difference schemes with spectral-like resolution. Journal of Computational Physics, 103, 16-42), while an explicit five-step Runge-Kutta algorithm by Kennedy et al. (1999; Low-storage, explicit Runge-Kutta schemes for the compressible Navier-Stokes equations. Technical report 99-22, ICASE.) is used for time integration. Turbulent inflow conditions are generated by a separate LES of fully developed supersonic channel flow at a bulk Mach number of M=3.1 and a friction Reynolds number of Re approximate to 456 and introduced well upstream of the injection station using characteristic boundary conditions. The complex transport processes of mass, momentum and energy in the neighbourhood of the injection region are documented by snapshots of instantaneous flow variables and by profiles and contour plots of statistically averaged quantities.