Advances in Numerical and Experimental Investigation of Screw Compressors

Industrial requirements for the rapid development of screw machines and accurate prediction of their performance constantly generate the need for further improvement in existing design procedures and the development of new modelling techniques. Advances in numerical methods and the exponential increase in computer power make three dimensional Computational Fluid Dynamics (CFD) into a most promising technique for the fine improvement of such machines and for evaluating their use in new applications. However, further validation of the accuracy of such procedures is required for them to be used for the design of novel screw machines. Moreover, if alternative methods are developed, which employ 3-D CFD, further validation is needed. Modern experimental methods such as Laser Doppler Velocimetry offer new insight in the flow within screw compressors. Fair agreement between predicted and measured flow patterns was obtained but the results show that more work in turbulence modelling is needed to improve this in defined regions of the compressor.