高海拔矿井风机气动噪声数值模拟及实验研究

为研究高海拔矿井风机气动噪声规律，建立小型轴流风机三维物理模型，利用CFD软件对环境气压分别为1，0.9，0.8，0.7，0.6及0.5 atm时的风机模型进行定常模拟、非定常模拟及噪声计算，并通过自主设计的压变实验装置对上述不同环境气压条件下风机转数分别为500，1 000，1 500和2 000 rpm时的风机噪声进行测试，分析风机叶片附近监测点噪声频谱曲线及压变环境风机噪声实验数据，结果表明:风机转数和环境气压是影响风机气动噪声的2个重要因素；环境气压P一定时，风机转数n越大，各频率下的风机气动噪声声压级SPL越大，且风机噪声总声压级Lp和平均声压级Lavg均随风机转数n的增大呈对数函数增加；风机转数n不变时，随着海拔高度的升高，环境气压P降低，各频段下风机气动噪声声压级SPL均将减小，且风机噪声总声压级Lp和平均声压级Lavg随环境气压值P的降低呈线性函数减小，环境气压每降低0.1 atm，二者分别降低1.47和1.29 dB。

Numerical simulation and experimental research on aerodynamic noise of fan in high altitude mine

In order to study the aerodynamic noise rules of fans in the high altitude mine,a three dimensional physical model of small axial flow fan was established.The CFD software was used to perform the steady simulation,unsteady simulation and noise calculation of the fan model when the ambient air pressure was 1,0.9,0.8,0.7,0.6 and 0.5 atm,respectively,and a self designed pressure varying experimental device was used to test the fan noise at the fan revolution of 500,1 000,1 500 and 2 000 rpm under different ambient air pressure conditions,then the noise spectrum curves of monitoring points near the fan blades and the experimental data of fan noise in the pressure varying environment were analyzed.The results showed that the fan revolution and ambient air pressure were two important factors affecting the aerodynamic noise of fan.When the ambient air pressure P was constant,the greater the fan revolution n,the larger the sound pressure level SPL of the aerodynamic noise for the fan under each frequency,and both the total sound pressure level Lp and the average sound pressure level Lavg of the fan noise increased as a logarithmic function with the increase of fan revolution n.When the fan revolution n was constant,with the increase of the altitude,the ambient air pressure P decreased,and all the aerodynamic noise sound pressure level SPL of the fan would decreased in each frequency band.Moreover,the total sound pressure level Lp and average sound pressure level Lavg of the fan noise decreased linearly with the decrease of ambient air pressure P,and each time the ambient air pressure decreased by 0.1 atm,they decreased by 1.47 and 1.29 dB respectively.