This study presents the investigation of flow field around corrugation. The impact pressure for two different impact velocities was tested. The model was tested for three different deadrise angles. The flow field was captured with high speed camera. The pressure time history was analyzed with pressure time history. The presence of air pocket was confirmed from the present analysis.
Much research has been done on flat plate and wedge impact problem (Verhagen, 1967;.Chuang, 1970; Chung, 2006; Chung, 2007; Nahm 2007). However, not much work has been reported on the flow field around corrugation. The presence of corrugation on the membrane has got a lot of advantages. From the fluid impact point of view it damps out impact pressure. However, it makes the flow field very complicated. It definitely defies any analytic approach. Therefore experimental investigation is very important to see what's going on around there. The present study dealt with flow field around large and small corrugations. The pressure was measured at three different locations. The flow field was recorded with high speed camera. The flow field was recorded from bottom and side of the water tank. The pressure time history was very helpful in the interpretation of the classification of the impact. In other words the impact can be classified into two categories. They are either Wagner type or Bagnold type. It was shown that all three pressure gauges were experienced with Bagnold type impact when the deadrise angle was 0°. However, the first pressure gauge got the Wagner type impact when it comes to the inclined impact. The pressure gauge located in the middle experience Bagnold type impact in the first stage. Later it escaped from the air pocket and got peak impact. This conclusion might not be easily drawn without analyzing pressure time history.