2001 Volume 49 Issue 574 Pages 375-381
An arc-heated wind tunnel has been used to produce nitrogen gas flow with high enthalpy to investigate physical phenomena along the stagnation streamline of a hemi-sphere cylinder with a diameter of 10 mm. The rotational and vibrational temperatures were measured by a spectroscopic method. The rotational temperature took a maximum value of 800 K at a location 2 mm upstream of the stagnation point, while the vibrational temperature showed a nearly constant value of 5, 500 K, which was much higher than the rotational temperature. This means that the present flow is in the state of thermal nonequilibrium. For comparison, the flow was numerically simulated by using the measured data as boundary conditions. As a result the calculated translational-rotational temperature was 80 K higher than the experimental data. Vibrational temperature had a tendency to decrease along the centerline of the wind tunnel, due to insufficient energy exchange between translational-rotational and vibrational energy.
