叶片形状对对旋风机正反风性能影响

Forward and reverse aerodynamic performance of different wing-shaped blades of a contra-rotating axial-flow fan

为保证对旋风机正风运行性能的同时提高反风运行能力,采用平面叶栅法设计了一台功率55 k W的对旋轴流风机。以C-4翼型为基础,采用CFD方法研究了叶片前缘和尾缘形状变化对对旋风机正反风性能的影响。研究表明:正风整机性能,双头尖叶形风机压升和功率明显高于原始翼型,大流量时其内效率高于原始翼型和双头钝叶形,小流量时其内效率低于这2种叶形。双头钝叶形压升和功率略低于原始翼型,内效率略高于原始翼型。反风整机性能,双头尖叶形和双头钝叶形反风全压和功率相差不多,均优于原始翼型,双头钝叶形反风内效率略高于双头尖叶形和原始翼型,原始翼型和双头尖叶形反风内效率接近。正风级性能,两级叶轮级性能变化趋势均与整机类似。反风级性能,双头尖叶形两级反风性能均优于原始翼型。双头钝叶形第一级叶轮性能低于双头尖叶形和原始翼型,第二级叶轮性能优于这2种叶形。可见,大流量时双头尖叶形对旋风机可更好地满足正反风高效运行的目的。

In order to ensure forward aerodynamic performance of the fans,and to improve reverse aerodynamic performance,a 55 kW counter-rotating axial-flow fan was designed by plane cascade method.Based on the C-4 airfoil,the effects of the shapes of the blade leading edge and trailing edge shape on the forward and reverse aerodynamic performance of the fans are studied by the computational fluid dynamics method(CFD).On the performance of the whole machine,when the fan is forward running,the study shows that the pressure and power of the double-headed tip blade fan is obviously higher than those of the original airfoil fan.The efficiency of the double-headed tip blade fan is higher than that of the original airfoil fan and double-headed blunt blade fan for high flow rate.Its efficiency is lower than them for low flow rate.The pressure and power of the double-headed blunt blade fan is slightly lower than that of the original airfoil fan,and the efficiency is slightly higher than that of the original airfoil fan when the fan is forward running.On the performance of the whole machine,when the fan is reverse running,the pressure and power of the double-headed tip blade fan and those of the double-headed blunt blade fan are similar and better than those of the original airfoil fan.The efficiency of the double-headed blunt blade fan is slightly higher than that of the double-headed tip blade fan and the original airfoil fan.The efficiency of the original airfoil fan is similar to that of double-headed tip blade fan.On the stage performance of the fan,when the fan is forward running,changes of performance of the two stage impellers are similar to those of the performance of the whole machine for three kinds of blade fans.On the stage performance of the fan,when the fan is reverse running,the performances of the two stage impellers of double-headed tip blade fan are superior to those of the original airfoil fan.The performance of the first-stage impeller of the double-headed blunt blade fan is obviously lower than that of the double-headed tip blade fan and the original airfoil fan.However,the performance of the second-stage impeller is better than them.It follows that a counter-rotating axial-flow fan of the double-headed tip blade is better to meet the high efficiency forward and reverse running for high flow rate.