轴向间距对矿用对旋式通风机性能的影响

Effects of axial gap on contra-rotating mine fan's performance

基于选取合理轴向间距的需要,通过大涡模拟(LES)对7种不同轴向间距的矿用对旋式主通风机的非定常流场进行数值计算,分析了额定流量下,该风机气动噪声特性、转子安全性和气动性能随轴向间距的变化情况。结果显示:气动噪声特性、转子安全性都随轴向间距增大而提高,但分别在轴向间距达到0.80倍和0.60～0.70倍第一级叶中弦长(b)后,变化趋势放缓,进一步增加轴向间距意义不大;而轴向间距在(0.55～0.60)b时气动性能达到最佳,后级转子的进气角、尾迹与主流的掺混是影响其变化的主要因素。研究结果表明,0.7b左右是该通风机综合性能较好的轴向间距范围。

Aimed at reference to guide the axial gap selection,unsteady numerical simulations were carried out on contra-rotating mine fans with seven different axial gaps by Large Eddy Simulation（LES）.For the rated condition,variations of the fan＇s aeroacoustic performance,rotor safety and aerodynamic performance caused by the axial gap were investigated.The aeroacoustic performance and rotor safety are improved as the axial gap grows,but over the axial gaps of 80% and 60%～70% of the first mean span chord（b） respectively,their variation tendencies slow down,so it＇s meaningless to lengthen the axial gap any more;at the axial gap of 55% to 60% of b,optimum aerodynamic performance is observed,in which inlet flow angle of the 2nd rotor and mixing between wake and main flow are two main influencing factors.Results show that favorable over-all properties appear in the fan with axial gap of about 70% of b.