Numerical simulation of the noise from a supersonic hot jet with high order finite difference scheme

In this study the screech tones from a supersonic hot jet is simulated with a high order computational aeroacoustic solver. The 4th order Dispersion Relation Preserving (DRP) scheme [25] is used for spatial discretization. The grid block interface flux reconstruction method (IFR) for high order finite difference scheme proposed by the present authors is utilized [26, 27] to handle the flux on the block interface. The Low-Dissipation & Low-Dispersion Runge-Kutta scheme [28] in the 2N storage form is employed for time integration. To eliminate the grid spurious oscillations, a high order explicit spatial filter is applied at each time step. An adaptive shock capturing method based on the variable stencil Reynolds number method of Tam & Shen [29] is adopted to capture the shock cells in the jet plumes, but has little influence on the other components in the flow field. Proper non-reflective boundary conditions are applied to the far-filed and outflow boundary regions. The simulation is conducted for the jet in the Mach number range from 1.2 to 1.56 at four reservoir temperature ratios (Tr{T₈), which are 1.0, 1.67, 2.32 and 2.78 respectively. The pressure field and shock-cell structures of the screeching jet are presented. The near field noise spectra are presented and analyzed. The computed frequencies and amplitudes of the screech tones from the cold jet are compared with the experimental data by Ponton et. al. [22], and a good agreement is obtained. The effects of the jet temperature on the screech tones are studied. It is found that the frequencies of the screech tones increase with the jet temperature, but the amplitudes decreases slightly with the temperature.