袋型阻尼密封转子动力特性的多频单向涡动预测模型

为了满足宽频域下阻尼密封转子动力特性的计算要求,针对单频涡动模型计算量大的问题,提出了采用动网格技术和非定常数值方法来预测袋型阻尼密封转子动力特性的多频单向涡动模型.以转子多频单向涡动位移作为激励信号,采用非定常方法和动网格技术进行了三维ReynoldsAveraged Navier-Stokes (RANS)方程的数值求解,从而获得了袋型阻尼密封的瞬时流体激振力.通过快速傅里叶变换,在频域内计算了10个频率的8个转子动力特性系数,并与实验值进行了比较.结果表明:数值计算得到的袋型阻尼密封转子动力特性系数与实验值吻合良好,从而验证了基于多频单向涡动模型的数值方法能够可靠预测袋型阻尼密封转子动力特性.

Multiple Frequencies One-Dimensional Prediction Model of Rotordynamic Characteristics for Pocket Damper Seals

A multiple frequencies one-dimensional analysis model using unsteady Reynolds-Averaged Navier-Stokes(RANS) solutions and the mesh deformation method was proposed to meet the requirements of computing rotordyanmic characteristics for pocket damper seals in a large frequency range and avoid the heavy computational effort resulting from the single-frequency vibration model.A multiple-frequency one-dimensional periodic orbit for rotor surface was viewed as the excitation signal,and the unsteady solutions combined with the mesh deformation method were employed to solve the three-dimensional RANS equations and obtain the transient reaction forces on the PDS rotor surface.The rotor motion signal and reaction forces signal were transformed to the frequency domain using the fast Fourier transform(FFT),and then the eight rotordynamic coefficients of the PDS were determined at ten different excitation frequencies.The results show that the predicted rotordynamic coefficients of the PDS by the present numerical method agree well with the experimental data,confirming that the multiple frequencies one-dimensional analysis model can be adopted for predicting the rotordynamic characteristics of the PDS.