Investigation of high-pressure turbulent jets using direct numerical simulation

Direct numerical simulations of free round jets at a Reynolds number ($Re_{D}$) $5000$, based on jet diameter ($D$) and jet-exit bulk velocity ($U_{e}$), are performed to study turbulence characteristics supercritical pressures. The consists $\mathrm{N_{2}}$ that is injected into same temperature. To understand turbulent mixing, passive scalar transported with the flow unity Schmidt number. Two sets inflow conditions model issuing from either smooth contraction nozzle (laminar inflow) or long pipe (turbulent considered. By changing one parameter time, examine jet-flow sensitivity thermodynamic condition (characterized in terms compressibility factor ($Z$) normalized isothermal compressibility), condition, ambient pressure ($p_{\infty}$) spanning perfect- real-gas conditions. affects statistics near-field (containing potential core closure transition region) as well further downstream fully-developed self-similar statistics) both atmospheric $p_{\infty}$. larger region, where laminar-inflow exhibit dominant coherent structures produce higher mean strain rates kinetic energy than turbulent-inflow jets. Decreasing $Z$ fixed $p_{\infty}$ enhances density fluctuations (normalized by local density, respectively), but effect depends also dynamics. When reduced, large region significantly enhance velocity) whereas effects minimal inflow.