An experimental investigation of the variation with water depth of lift or drag coefficients of a body on or near the bottom of a flowing stream

An experimental investigation was carried out for the purpose of determining the influence of the depth of water upon the coefficients of lift and drag of a submerged body on or near the bottom of a flowing stream. This investigation made use of the facilities of the Rice University wave tank. Two types of models were employed in this study, an upright flat plate attached to the bottom and a cylinder with a clearance of ,12 diameters above the bottom. The results of the tests indicate that the drag coefficient increases as the size of the body increases in relation to the depth of water, while the lift coefficient does not exhibit such an increase, A method is developed which predicts the shallow-water drag coefficient with an accuracy of +/- 1% if the value of the deep-water coefficient and the upstream conditions are known. The same method can be used to obtain a deep-water coefficient from tests conducted in shallow water