Extending the role of computational fluid dynamics in screw machines

Abstract

Previous publications show that computational fluid dynamics (CFD) can be readily used for the flow prediction and analysis of screw compressors. Several case studies are presented in this article to show the scope and applicability of such methods. These include solid–fluid interaction in screw compressors, prediction of flow generated noise in screw machines, cavitation modelling in gear pumps, and flow in multiphase pumps for oil and gas industry. Numerical grids for all these cases were generated by the authors using an in-house grid generator, while the CFD calculations were performed with a variety of commercially available CFD codes. In order to validate the accuracy of the CFD calculations, an extended test programme was carried out using laser Doppler velocimetry to measure the mean and fluctuating velocity distribution in screw compressor flow domains. The measurement results are then compared with the CFD simulations. The results confirm the viability of the developed techniques. It is shown in this publication that the flexibility of the developed method creates further opportunities for a broader use of CFD for analysis of twin screw machines in a range of new applications.