Numerical investigation of supersonic two-component jet flow

This study investigates the flow structures and acoustic properties of supersonic jets that release various gases into quiescent air. Numerical simulations are performed on air, hydrogen, and argon jets discharging into an air-filled domain at a Mach number of 2.1 and a Reynolds number of 70 000. The reactingQGDFoam solver is used, which implements quasi-gasdynamic (QGD) equations for homogeneous ideal gas mixtures. This solver is coupled with the libAcoustics library for aeroacoustic analysis. The influence of gas composition on the mean, instantaneous, and acoustic characteristics of the flow is quantified, including the length of the potential jet core, peak acoustic radiation directivity, and turbulent mixing mechanisms. Although all gases demonstrate universal power-law expansion behavior, hydrogen exhibits delayed self-similarity because of competing inertial and turbulent diffusion effects. Additionally, decay law exponents are determined for the mean streamwise velocity of all fluids.