Calculation of Shock Shapes over Sharp Cone in Intermediate Hypersonic Airflow

摘要

Shock shapes over a sharp cone in the intermediate hypersonic flow regime are calculated to examine the validity of the existing two-temperature thermochemical model. Two different apex angles are considered in the calculations: one with a half-angle of 30 deg and the other with 45 deg. The calculations for these geometries are carried out for several different static pressure values at the flight velocity of about 3.0 km/s. The calculated shock layer thickness is compared with the corresponding experimental data obtained in a ballistic range. The results show that the two-temperature model well reproduces the experimental data for the flow conditions in which chemical reactions as well as vibrational excitations are absent. However, the calculated shock layer thickness tends to be thinner than the experimental data for the flow conditions in which vibrational excitation begins to occur. It is implied that vibrational relaxation has a close connection with the thinner shock layer. The study confirms our previous results that the shock layer thickness over a sphere in the same velocity range can be underestimated in the calculation using the existing two-temperature model.