Planar Laser-Induced Fluorescence Imaging of Hypervelocity Flows: Computer Simulation and Sensitivity Analysis

Principal Investigator

A F P Houwing

Department of Physics,

The Faculties

We use computational fluid dynamics (CFD) codes on the VPP to predict flow over model aerospace
vehicles. The results of the CFD are used together with a new computational method we have developed to predict planar laser-induced fluorescence (PLIF) images. PLIF is an optical method for measuring parameters of gas flows, such as temperature and velocity. We use this computational method to predict how our experimental PLIF images will look. Also, the computational images have other uses: they can be used to design PLIF experiments, test various assumptions used in PLIF, or they can allow a direct comparison between experiment and theory that can validate the CFD model used.
   

Co-Investigators

     

P M Danehy

Department of Physics, The Faculties

R R Boyce

Mechanical Engineering,

University of Queensland

     
             

     
             

Projects

v59 - VPP

           

What are the results to date and the future of this work?

We recently studied a series of geometric bodies computationally on the VPP. We investigated Mach 8 flow over a hemisphere and a wedge. The CFD code computed the fluid mechanics and the non-equilibrium chemistry associated with these high-speed flows. We used the results of the CFD code for direct comparison with our PLIF temperature measurements. We also computed PLIF images using the method described above. In both comparisons, agreement was excellent for flows that were vibrationally frozen. However, agreement between experiment and theory was not as good where vibrational non-equilibrium occurred. Since the current CFD code does not compute vibrational non-equilibrium we will have to use a new CFD code in the future to achieve better agreement.

This work has resulted in three conference presentations and two conference papers in 1997.

What computational techniques are used?

We used a CFD program written by Dr. Ch. Mundt from MBB in Germany.

Publications

P. Danehy, P. Palma and A. Houwing, Comparison of theoretical and experimental laser-induced fluorescence images in hypersonic shock-layer flows, in Proceedings of 21st International Symposium on Shock Waves, Great Keppel Island, Australia, (conference abstract), pp. 143 (1997).

               
- Appendix A

 
               
       

P. Palma, P. Danehy and A. Houwing, PLIF imaging of nitric oxide in luminous, reacting, hypersonic flows, poster session at Gordon Conference on the Physics and Chemistry of Laser Diagnostics in Combustion, Plymouth, NH, 1997.

P. Palma, P. Danehy and A. Houwing, Non-Intrusive Thermometry in High-Enthalpy Shock Layers Using Multi-Line Fluorescence Imaging, in Proceedings of 21st International Symposium on Shock Waves, Great Keppel Island, Australia, (conference abstract), pp. 59 (1997).

       
Appendix A -