A comparison of measured and predicted test flow in an expansion tube with air and oxygen test gases
Abstract
Simultaneous time-resolved measurements of temperature, density, pitot pressure, and wall pressure in both air and O2 test gases were obtained in the Langley pilot model expansion tube. These tests show nonequilibrium chemical and vibrational relaxation significantly affect the test-flow condition. The use of an electromagnetic device to preopen the secondary diaphragm before the arrival of the primary shock wave resulted in an improvement in the agreement between the measured pitot pressure and the value inferred from measured density and interface velocity. Boundary-layer splitter plates used to reduce the wall boundary layer show that this disagreement in the measured and inferred pitot pressures is not a result of boundary-layer effects.
- Publication:
-
NASA STI/Recon Technical Report N
- Pub Date:
- December 1975
- Bibcode:
- 1975STIN...7615410A
- Keywords:
-
- Flow Measurement;
- Pitot Tubes;
- Prediction Analysis Techniques;
- Air Flow;
- Oxygen;
- Shock Waves;
- Static Pressure;
- Velocity Measurement;
- Wall Pressure;
- Fluid Mechanics and Heat Transfer