轴流式前弯动叶的变工况气动性能实验研究

对前弯宽、窄动叶片和常规直叶片进行了变工况气动性能的实验研究。通过对实验结果的分析发现：相对于直叶片，前弯窄叶片不仅可以提高气动效率，而且扩大了风机的稳定工作范围，只是动叶动压头有所降低；前弯宽叶片的稳定工作范围则比窄叶片要宽，其气动效率和动叶压头也有大幅度的提高。这说明在提高效率、扩大稳定工作范围方面，动叶前弯和增加弦长同时起到积极的作用。还对三种动叶片的出口气动参数沿径向的分布规律进行了详细的测量，并对最高效率点和旋转失速前最小流量点的气动参数沿径向的分布规律进行了重点分析，从流体力学原理出发，解释说明了前弯动叶片提高效率，扩大稳定工作范围的原因。

Experimental research on the off-design performance of the axial rotors with forward-skewed blades

In this paper, the experimental research has been carried out on aerodynamic performance of the axial flow fans, including the radial straight blades, the forward-skewed narrow-chord blades and the forward-skewed wide-chord blades respectively. The radial straight blades have the same section geometric parameters as the forward-skewed narrow-chord blades. The chord of forward-skewed wide-chord blade is about 20% greater than that of the forward-skewed narrow-chord blades. Based on analyzing and comparing the results gotten from the experiment, it is well found that rotor with forward-skewed blades can enlarge the steady operation range and increase the efficiency of the fan compared with the rotor of radial straight blades. And, increasing the chord length is another important reason for which the fan performance is improved greatly. At the same time, the aerodynamic parameters distribution along the radial direction at outlet have been measured, including the total pressure loss coefficient, axial velocity, radial velocity and outlet relative flow angle at two typical working points of the minimum flow rate point before rotating stall and the maximum efficiency point.