This paper presents an approximate method of calculating the laminar boundary layer on a propeller blade. The momentum integral equations have been derived of a rotating blade under the following assumptions : (1) contour of the blade is sector, (2) pressure gradient is arbitrary in the circumferential direction, but is zero in the radial direction. The equations were applied to propeller blade sections at several radial positions separately, assuming that the interraction between the flows of adjacent sections could be ignored. Velocity profiles across the boundary layer were expressed by nth-order polynominal expressions similar to Pohlhausen's method. Numerical solutions were obtained of three kinds of simple rotating bodies and a model propeller. The results of the latter were compared with the flow patterns obtained by means of the oil-film method.
