Three-Dimensional Modelling of Solid-Fluid Interaction as a Design Tool in Screw Compressors
In order to reduce internal leakage in screw compressors, efforts are continually being made to produce them with smaller clearances. However, since their rotors deform due to the high pressure loads under which they operate, a reliable estimate of the interaction between rotor deflection and fluid flow is needed to maximise the compressor performance while avoiding contact with the casing. A 3-D numerical grid comprising both solid and fluid domains, applied to a commercial computer code for simultaneous calculation of the fluid flow and compressor structure, is presented here. This demonstrates the effects on compressor torque, volume flow, efficiency and specific power due to the change in working clearances caused by rotor deformation.