Thanks to TwinMesh software, computational fluid dynamics (CFD) has become an efficient development tool for the first time also for manufacturers of rotary positive displacement machines.

An important prerequisite for reliable CFD simulations, is the creation of high-quality meshes that mimic the computational domain as precisely as possible, without increasing too much the model number of elements.

The creation of such computational domain poses two significant challenges for engineers when working with rotary pumps, gear pumps and screw compressors. The complexity of the geometry of rotary positive displacement machines results from the flow volumes in the working chambers which vary over time. The second challenge are the extremely small gaps between the rotors and between the rotors and the housing.

With the help of meshing software TwinMesh, the time-varying flow volumes and gaps in the working space of volumetric machines can be automatically meshed with high-quality structured hexahedral meshes, for a number of angular positions specified by the user. By using a smoothing algorithm contained in TwinMesh, the node distributions always remain homogeneous, and the interior element angle remains nearly orthogonal.

TwinMesh provides also special templates for all typical displacement machines, taking care of the actual simulation setup, monitoring and post-processing in ANSYS CFX simply pressing a button.