2005 年 48 巻 160 号 p. 110-116
The flow fields around a large apex angle, spiked blunt cone have been analyzed at a hypersonic Mach number through experiments in a free piston-driven shock tunnel, and the results are compared with that of a laminar 2-dimensional axisymmetric unsteady Navier-Stokes solver developed in-house. The model geometry is a 120° apex angle blunt cone equipped with two types of spikes — a disc-tipped spike and a conical-tipped spike. The ratio of total length of the spike to model base diameter was kept at 1.00. The free-stream Mach number and Reynolds number (per unit length) in the free piston shock tunnel were 6.99 and 2.46×106, respectively. After measuring the aerodynamic forces on this model, time resolved visualization of the flow was attempted using a high-speed video camera in order to understand the characteristic features of the high-speed flow over the spiked body and to check if any unsteadiness existed in the flow fields. The experimental results indicate slight shock oscillations near the edge of the cone model when it is equipped with a disc spike, and the shock oscillations appear to be more pronounced when the model is equipped with a conical spike. However, the pulsation flow mode is not observed in the experimental results. The numerical results agree with the experimental results on the unsteadiness of the flow fields. The experimental results obtained in this case also serve as a database for the in-house CFD code validation for such high-speed spiked body flows.