research & development


previous system will be discussed in more detail.


PIV measurements were performed in MARIN’s Deep Water Towing Tank on a surface piercing flat plate. MARIN carried out these benchmark tests as part of the HydroTesting Alliance (HTA) project. HTA is the European FP6 Network of Excellence set up to facilitate the continuation of world leadership of the European hydrodynamic testing facilities. The objective of this alliance is to develop a formal and lasting structure to coordinate the definition and introduction of novel measurement tech- niques for ship model testing. The flat plate was selected as a benchmark geometry by the HTA and was towed at an incidence of 20 degrees, while measure- ments were made at a plane next to and in the wake of the plate. Although a simple geometry, a lot of important phenomena such as vortices, velocity gradients, free surface deformation and wall surface reflec- tions are present. This benchmark test gives insight into the state-of-the-art stereo-PIV capabilities in different testing facilities.


Valuable future use The advance of computational techniques allows hydrody- namicists to obtain flow fields numerically as well. Therefore, a separate numerical ex- ercise using the viscous-flow solver FreSCo to predict the flow around the flat plate was performed. FreSCo is a URANS solver for general hydrodynamic purposes. Availability of the measurement data and the computed data provides a unique chance to cross- compare both experimental and computa- tional results. The calculation was conduct- ed using the same conditions deployed during the measurement tests. The only simplification made was the neglect of the deformation of the free surface. The location of the measurement plane relatively far from the free surface and the moderate ve- locity justify this simplification. Careful com- parisons between the predicted and meas- ured velocity fields show that they concur very well. The magnitude and position of the vortex sheet coming from the lower edge of the plate are well resolved. Both the PIV system and FreSCo, are valuable tools for future projects.


Impression of pressure and vorticity (CFD) and flow field (PIV) around surface-piercing flat plate at incidence


Calculated (left) and measured (right) vertical velocity fields


New MARIN PIV system in Deep Water Towing Tank report 19


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