A measurement study of a pressure transducer subjected to water drop impact

Abstract

Numerous numerical methods exist that can be used to solve fluid/structure interactions during hydrodynamic impacts on deformable structures. In order to validate these methods, experimental references are needed and the use of pressure transducers appears to be quite sensible and natural. But the objectivity of such a pressure measurement may sometimes be questioned (bias due to the presence of the transducer itself, which has its own dynamic natural response). Such a systematic error is difficult to notice when structural tests are concerned, other uncertainties concerning the experimental configuration being possibly called for as an obvious explanation of any differences between test and simulation results. The purpose of the present paper is to propose a methodology of exploitation of dynamic tests responses, dedicated to the elimination of such measurement errors if needed, in order to get the true contact pressure that deformable structures have to support during hydrodynamic impacts. For that purpose, the dynamic calibration of a pressure transducer is performed using a shock tube, and a dynamic correction function is established, first theoretically, then practically. The obtained function is then applied on existing test results coming from water drop impacts onto the studied pressure transducer, in order to calculate the corresponding contact pressure on a flat panel, and to compare these latter data to different FE simulation solutions.

Keywords:

• pressure
• measurement
• hydrodynamic
• fluid–structure interaction
• shock tube

Acknowledgements

This research work was grant-aided by Region Nord-Pas de Calais. The authors are thankful to this institution for its financial support. The authors also thank M. M. A. Deudon, J.-M. Desse, J. Fabis and J.-M. Mortier equally for their technical help and knowledge.