AIRFOIL FOR AXIAL FLOW COMPRESSOR ENABLING LOW LOSS IN LOW REYNOLDS NUMBER REGION

摘要

PROBLEM TO BE SOLVED: To reduce pressure loss of an airfoil for an axial flow compressor in a low Reynolds number region while ensuring a reduction effect of pressure loss in a high Reynolds number region.;SOLUTION: In a sub-sonic velocity region wherein a Reynolds number is equal to or smaller than a critical Reynolds number, a flow rate distribution on a back surface side of the airfoil has one maximum value of a supersonic velocity within 6% from a leading edge. Alternatively, a shape factor has a maximum value in a region of 6 to 15% from the leading edge on a code, is almost constant in a region of 30 to 60% and gradually increases to 2.5 in a downstream region from 60% of the code. A position where a flow rate has the maximum value immediately after the leading edge on the back surface of the airfoil particularly approaches a leading edge side as compared with a conventional airfoil (CDA). Initial transition from a laminar boundary layer to a turbulent boundary layer is resultantly facilitated and the turbulent boundary layer in a rear portion on the airfoil back surface downstream of the transition point is held in a very stable state.;COPYRIGHT: (C)2008,JPO&INPIT