Abstract: In order to meet the requirement of alternating air flow direction of fan, a new aerofoil of axial-flow fan blade-reversing symmetrical aerofoil with double leading edges is presented in the paper. Using optimal control theory we designed and constructed a new type axial-flew fan, which can alternate the direction of ventilation by simply reversing the rotation of motor. The experimental data of fan and other flow parameters along the blade are shown in good agreement with the calculated. Depending upon the condition in service, the axial-flow fan with new aerofoil blades can drives the air in one or other direction with same characteristic value so as the volume flow, pressure and efficiency. The feature of the fan is its simple construction, convenient adjustment and the good general characteristics of normal and reverse ventilation.

Key words: 优化设计, 轴流式通风机