Screw Compressors- Mathematical Modelling And Performance Calculation -
Where:
From this geometry, we calculate primary parameters: Where: From this geometry, we calculate primary parameters:
Challenge: Moving, deforming meshes require significant computational resources (hours to days per operating point). in - h_leak
The energy equation for oil droplets:
Mathematical modelling of screw compressors has evolved from simple geometric volume calculations to sophisticated multi-physics simulations that integrate thermodynamics, fluid leakage, heat transfer, and rotor dynamics. Engineers today can accurately predict performance—volumetric efficiency, power, discharge temperature—using 1D chamber models for design optimization and CFD for detailed validation. Where: From this geometry
This differential equation is solved numerically using methods like the Runge-Kutta technique. It links the change in internal energy to the enthalpy of incoming flows, the work done by the gas expansion/compression ($pdV$ work), and heat transfer.
[ \fracdUd\theta = \dotm in h in - \dotm out h out - \dotQ wall - \dotW shaft + \dotm leak (h leak,in - h_leak,out) ]