Experimental investigation on aerodynamic performance of one typical helicopter rotor airfoil

Selecting airfoils with high lift-drag ratio is the key for improving aerodynamic performance of helicopter rotor.The CH309 rotor airfoil was developed based on typical OA309 rotor airfoil,and the experimental investigation on low and high speed aerodynamic performance was made.The tests were performed in a two-dimensional testing section of FL-14 wind tunnel at China Aerodynamics Research and Development Center and NF-6 wind tunnel at Northwestern Polytechnical University respectively.Surface pressure measurement and drag measurement with trail total pressure row tube were carried out.Experimental results show that the overall performance of CH309 airfoil is better than that of the OA309 airfoil.These experimental results are valuable for the airfoils′ selection of designing helicopter rotor.