Aerodynamic loads determination in supersonic and hypersonic flows based on PIV

Paper number

IAC-06-C4.P.5.05

Author

Mr. Louis Souverein, France

Year

2006

Abstract

Among the most important parameters for the characterisation of any aerodynamic body are the loads induced by the action of the flow. These loads include distributed surface loading in for example air intakes or rocket nozzles, as well as the ballistic coefficient, which determines the path of re-entry of a spacecraft. This research proposes a new method for experimental loads determination, based quantitative velocity field information obtained by means of Particle Image Velocimetry (PIV). This technique has since recent times been applied to supersonic and hypersonic flows. Apart from yielding useful qualitative information about flow features, it also yields qualitative velocity field information. This information can be used as an input for aerodynamic models to compute pressure and density fields. This information can then be used to compute integral as well as distributed loads, although the latter are more ambitious.

The existing applications of PIV-based loads determination are all limited to incompressible flows. The aim of this research is therefore the extension of this approach into the high-speed flow regime. This introduces significant additional complications, like the density as additional flow variable and the occurrence of discontinuities in the flow field. The focus is on the development of the required theory to experimentally determine loads in compressible flow conditions in the presence of shock waves, the implementation numerical of the new approach and the experimental verification based on synthetic data as well as PIV measurement data. Overall, the current method constitutes the first approach to high-speed PIV based experimental loads determination.

The first applications of this research are the experimental determination of lift and drag on an airfoil in a high-speed flow. The method will be extended to the evaluation of surface forces, particularly in the field of shock wave-boundary layer interaction. This is a phenomenon that occurs in for example intakes of air-breathing propulsion systems as well as in expansion nozzles. A future extension includes the determination of the load on a rotationally symmetric re-entry capsule in hypersonic flows.

Abstract document

IAC-06-C4.P.5.05.pdf

Manuscript document

IAC-06-C4.P.5.05.pdf (🔒 authorized access only).

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