平行平板曳航法による塗装面の乱流摩擦抵抗計測

抄録

 In ordinary displacement type ships, frictional drag is the largest component of total ship drag. Generally, it is difficult for common towing tank test to evaluate, within an accuracy of 1%, the difference in frictional drag of a ship for different surface conditions. This difficulty comes from the fact that each measurement is carried out under different tank conditions, i.e., they are due to the disturbance in the towing tank, difference in temperature gradient, fluctuation of towing force, existence of seiche in the tank, etc. The present method is intended to cancel out experimental errors from these causes by using a newly developed parallel towing system. In the present method, a test plate and a reference plate are set parallel to each other and towed simultaneously in the towing tank. In this report, a brief introduction of the present method and discussion of experimental results are presented.