Experimental Design for the Determination of Anchor Chain Drag Coefficients in Current
水流中锚链阻力系数测量的实验设计

A simple and effective experimental design is presented in this paper to determine anchor chain drag coefficient in a towing tank. Due to the weight and flexibility of chain cable, three measures were taken as follows: (1) making the tested anchor chain into a straight bar by spot-welding the joints of two adjacent links; (2) hanging the tested bar horizontally below a moving carriage to simulate water current, then calculating the resistance based on the measurement of angle between suspending line and perpendicular; (3) in order to eliminate the influence of bar ends, drag force is obtained by dividing the force difference derived from a long bar and a short bar respectively, by the length difference of two bars. Consequently, anchor chain unit drag coefficient induced by water current was easily derived.