CFD-Predicted Rotordynamic Characteristics of Helically-Grooved Liquid Annular Seals Based on Improved Dynamic Mesh Method

This paper develops an independent two-control equation for rotor's whirling motion and rotating motion to calculate the rotordynamic coefficients of the Helically-Grooved liquid annular seal by using dynamic mesh method in software. The independent two-control equation can avoid the tangential stretching of the internal mesh nodes of the surface of the rotor, so the tangential deflection of the mesh is greatly reduced. The calculation results show that the two-control equation in dynamic mesh method can improve the predictions of cross-coupling dynamic coefficients which are more related to the circumferential flow field. Compared with the single-control equation dynamic mesh calculation, this method is more accurate. The calculation result by using the two-control equation method is closer to the experimental data.