A series of experiments studying nitrogen flow over double-wedge geometries has been conducted in the T5 shock tunnel at Caltech. These experiments were designed with computational fluid dynamics to test the non-equilibrium chemistry models used in computational fluid dynamics codes. Surface pressure and heat transfer rate measurements have been made. In addition, holographic interferometry was used to visualize the flow. Analysis of the data shows CFD cannot reproduce of the experimental results. The computed separation zones are smaller to those seen experimentally. The computed pressure peaks on the second wedge are smaller than the measured values. The computed heat transfer values match the experimental data in the separation zone. On the second wedge the computed heat transfer distribution matches the shape and heights of the experimental distribution but is shifted due to the difference in the size of the separation zones. The failure of the CFD to match the experiments is not believed to be due to grid resolution effects, modeling of the viscous terms, turbulence, or flow unsteadiness. While inadequate models for real gas and vibrational non-equilibrium eifects may be responsible for the failure of the CFD, no definite conclusions can be drawn yet. Further work is being done to explain these discrepancies.
|Original language||English (US)|
|State||Published - 1996|
|Event||Advanced Measurement and Ground Testing Conference, 1996 - New Orleans, United States|
Duration: Jun 17 1996 → Jun 20 1996
|Other||Advanced Measurement and Ground Testing Conference, 1996|
|Period||6/17/96 → 6/20/96|