Unique Characteristics of Cryogenic Nitrogen Jets Under Supercritical Pressures

Two-dimensional planar and three-dimensional round nitrogen jets under supercritical pressures are simulated with a wide range of conditions to explore their unique characteristics. A high-order method using a sixth-order compact scheme is applied. The present study parametrically covers two supercritical pressures of 4 and 8 MPa and three jet injection temperatures between a cryogenic jet of 82 K and a warmer jet of 133 K. Unique characteristics are found in both the mean temperature and temperature fluctuation profiles on the centerline (i.e., slower increase of jet temperature and relatively weak temperature fluctuation), only in the case of a near-critical pressure of 4 MPa and a cryogenic jet of 82 K. For the condition, the temperature profile on the centerline uniquely consists of four characteristic regions. The other conditions show no distinct features. The present study suggests that the distributions of the specific heat capacity at constant pressure help to explain the generation of the unique...