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基于变螺旋角蜗壳型线设计方法,通过大涡模拟(LES)计算风机内部的非定常流场,利用二次回归正交试验设计法,对某离心风机的蜗壳型线进行数值优化以降低风机的A声级。优化时以蜗壳型线起始和终了位置的螺旋角为设计变量,以非定常流场计算得出的时均效率和A声级为目标函数,通过优化得到使风机气动噪声最低的最佳螺旋角分布,进而得到最佳蜗壳型线。利用数值模拟对优化结果进行了验证,验证结果表明:优化之后,时均效率降低了0.07%,A声级降低了4.04dB,时均效率和A声级相对于原风机分别降低了0.09%和4.51%;本次二次回归正交试验优化具有较高的预测精度,与CFD数值验证得出的时均效率和A声级的相对误差分别为0.01%和0.53%。
Based on the variable spiral angle volute profile design method, the unsteady flow field inside the fan is calculated by LES and the quadratic regression orthogonal design method is used to optimize the volute profile of a centrifugal fan Lower fan A level. In the optimization, the helix angle at the beginning and the end of the volute profile is taken as the design variable, and the time-average efficiency and A-sound level calculated by the unsteady flow field are taken as the objective function. By optimizing, the aerodynamic noise is minimized Spiral angle distribution, and then get the best volute line. The optimization results are verified by numerical simulation. The results show that: after optimization, the hourly average efficiency decreases by 0.07%, the A sound level decreases by 4.04dB, the hourly average efficiency and the A sound level decrease by 0.09% 4.51%. The quadratic regression orthogonal test has higher prediction accuracy. The relative error between time-average efficiency and A-level obtained by CFD numerical verification is respectively 0.01% and 0.53%.