Resistance Test in the Circulating Water Channel

Abstract

During a recent decade in Japan, more than 20 circulating water channels have been constructed. The Circulating water Channel Group (CCG) was organized in 1966 and has been studying the improvement of the performance of the channel itself as well as the development of diversified test techniques. In 1971, the CCG decided to perform a co-operative resistance test of the standard model for the purpose of ascertaining the accuracy of the tank tests at sizes 2.O and l.5 meters in model length. This group has been devoted to this work for three years now. The results of resistance test are more individual among the water channels than among the towing tanks. Two important factors affecting the test results clarified through our study are the gradient of the free surface and the steady wave accompanied by the flow particularly in high speed range. The remedies for these factors lead the discrepancy of the test results to a fairly good agreement.