Narrow Results

Energy components in the flow field at high angle of attack were analyzed by the dynamic measurement. The effect of the unsteadiness induced by these components on the flow was analyzed as well. The results showed that the flow itself at high angle of attack is a kind of "vortices behavior" and the effect of unsteadiness on the asymmetry of flow is relatively weak. The key factor that can essentially affect the flow at high angle of attack is the response of the dynamic unsteadiness of the vortices to the unpredictable micro-disturbance coming from near the nose of the model.

Investigation of Reynolds number effect on flow asymmetry over slender bodies at high incidence was conducted. Results show that increasing of wind velocity affects flow asymmetry by changing the intensity of the vortices; Model scale affects the distance between the main vortices, which determines the stability of the vortices and results in the discrepancy in the flow asymmetry over different scale models.

A method to determine swash zone boundary conditions is developed using remote sensing by video and ARGUS. Guard and Baldock (2007) proposed new numerical solutions for swash hydrodynamics, where the flow field varies according to a free parameter, k. k=0 in the Shen and Meyer swash solution but k=1 appears more realistic for real swash. This study has developed a semi-automated method to obtain values for k from multiple waves in field conditions using ARGUS video data and image analysis techniques. The results indicate that k is greater than 0 and close to 1 for natural swash. No trends were observed between k and run-up length, offshore significant wave height or tidal phase, consistent with the self-similarity of the swash hydrodynamics. In conjunction with modelling, the method offers the possibility of remote sensing of the asymmetry in the swash zone hydrodynamics.