Abstract
Direct flow drag measurement device for obstacles placed in the boundary layer has been developed and effect of angle of attack for drag acting on the pyramid has been investigated experimentally. Reliability of the developed measurement device was confirmed with a corn which drag force can be obtained by wall static pressure measurement. Apex angel of the pyramid is 2_α=60° and ratio between the height of the pyramid and the boundary layer thickness is δ/h≒0.52. Flow drag was measured at various angle of attack γ for the pyramid. Drag coefficient takes the maximum value near γ=0° and almost constant at |y|≧15°. Variation of the drag coefficient for angle of attach has abrupt change at |γ|=3°.
