Windback Floating Oil Seal Optimization Using CFD

Floating oil ring seals are used at the shaft ends of centrifugal compressors to eliminate process gas leakage to the atmosphere. The windback feature of the seals consists of several spiral grooves machined into the inside diameter of the seal ring. These grooves use the rotation of the shaft to reduce sealing oil leakage. Because of the complex fluid behavior in and around a windback seal, it is difficult to develop a design tool for accurate prediction of leakage. To address this, a comprehensive CFD model was created to predict performance of windback seals. Then a Design of Experiments approach was used to create a response surface model of the seal leakage as a function of several geometrical and operational parameters. The response surface predictions are compared with available experimental data.