Effectiveness of Windage Features on High Speed Couplings

Abstract

Following the changes to API 671, there is a requirement to reduce temperature around guarded coupling designs. Existing features used in high performance (HP) couplings involve various methods of shrouding and covering prominent rotating parts to ensure a smooth, rounded profile. The extent of the features are raised in line with increased peripheral speed. These key features are difficult and expensive to manufacture and can create high stress concentrations. This had lead to the investigation of the efficiency of the features. Traditional methods involve extensive test work, but due to the advances in computational fluid dynamics (CFD), the technology is now far more accessible to mainstream industry and can be used to analyze more complex coupling assemblies. This has allowed evaluation of windage features and their effect when rotated within a guard. Various geometric features have been analyzed using CFD and verified with test work, starting with a coupling equipped with all available windage features through to all of them removed. The initial results highlight that windage features fail to make a significant impact in reducing guard temperatures, hence further investigation has been planned.