【摘要】 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%。更多还原

【Abstract】 Three-dimensional unsteady viscous simulation by the model LES about the flow is executed to obtain the time-averaged efficiency and A-weighted sound pressure level of a centrifugal fan.A numerical optimization of the volute configuration of a centrifugal fan based on the idea of variable helical angles is carried out.The scheme of the numerical experiment is arranged according to the quadratic orthogonal regression experimental design method.Multi-objective optimization based on the sample points is performed:the starting and ending helical angles of the volute configuration are the design parameters,and the objective functions are the time-averaged efficiency and A-weighted sound pressure level.With the arrived optimal helical angles,the volute configuration is determined.A numerical validation is provided.The results show that the fan’s efficiency and A-weighted sound pressure level decrease by 0.07% and 4.04 dB,0.09% and 4.51% relative to the original fan,respectively.The optimization method has high accuracy.The relative error of the method is 0.01% and 0.53%,respectively.更多还原