This tunnel consists of a high pressure chamber and a low pressure chamber separated by an aluminium diaphragm. When the diaphragm is ruptured, a shock wave is driven through the lower pressure (test) gas which is thereby compressed and accelerated. When operated as a shock tube, optical access is obtained through four windows positioned near the end of the tube within which the model is mounted. For operation as a shock tunnel, a nozzle is attached to the end of the tube and optical access obtained through windows mounted in the dump tank. In each case the test time is of the order of several hundred microseconds. The test section has good optical access with four 100 mm diameter quartz windows.
Typical flow conditions achieved assuming equilibrium chemistry:
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Pressure (kPa) |
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Temperature (K) |
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Density (kg/m3) |
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Enthalpy (MJ/kg) |
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Velocity (km/s) |
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Mach Number |
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Diss. fraction N2 |
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Diss. fraction O2 |
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%NO |
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Ion. fraction N |
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Ion. fraction O |
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