TwinMesh

From CFD-Wiki

Contents 1 TwinMesh 1.1 Mesh Types 1.2 Meshing Techniques 1.3 Geometry Support 1.4 Rotary Positive Displacement Machines 1.5 CFD Solver Interfaces 1.6 Supported Platforms 1.7 Literature 1.8 External Links

TwinMesh

TwinMesh is a meshing software developed by CFX Berlin Software GmbH, Germany. It automatically generates hexahedral meshes for the CFD simulation of the continuously changing fluid volumes of the working chambers of rotary positive displacement machines. The product was released in 2014.

The current product release is Version 2017 (v3.0.11.0), released in November 2017.

Mesh Types

TwinMesh can generate structured hexahedral meshes.
TwinMesh can generare unstructured tetrahedral meshes for the axial gaps of rotary positive displacement machines.

Meshing Techniques

TwinMesh's mesh generation employs the following meshing techniques and smoothing algorithms.

• Option to fix the nodes along the rotors, which results in a general interface between the rotor meshes.
• Option to fix the nodes along the housing geometry to get an 1:1 interface between the rotor meshes.
• Option to fix the nodes on one of the rotors so that the nodes on the other rotor are able to move. This method also results in an 1:1 rotor interface.
• Option to mesh rotors with variable pitch.
• Manual adjustment of individual nodes.
• Node mapping at general grid interfaces.
• Various smoothing algorithms to control mesh orthogonality and node equidistance in all three dimensions.
• Mesh quality check such as: determinant, min. angle, volume change, aspect ratio.

Geometry Support

TwinMesh supports IGES (.iges) and point data (.csv).

The following geometry modifications are available in TwinMesh:

• Rotor scaling
• Rotor translation
• Rotation angle offset

Rotary Positive Displacement Machines

TwinMesh allows meshing of the following rotary positive displacement machines:

• Internal/external gear pump
• Gerotor pump
• Vane pump
• Lobe pump/blower
• Rotary piston pump
• Scroll compressor/expander
• Screw compressor/expander
• Eccentric screw pump/progressive cavity pump
• Wankel engine

CFD Solver Interfaces

TwinMesh has built-in support for ANSYS CFX.

Supported Platforms

TwinMesh supports 64-bit Windows versions.

Literature

• Hesse, J., Spille-Kohoff, A., Hauser, J., & Schulze-Beckinghausen, P. (2014). Structured meshes and reliable CFD simulations: TwinMesh for positive displacement machines. In International screw compressor conference, TU Dortmund.
• Spille-Kohoff, A., Hesse, J., & El Shorbagy, A. (2015, August). CFD simulation of a screw compressor including leakage flows and rotor heating. In IOP Conference Series: Materials Science and Engineering (Vol. 90, No. 1, p. 012009). IOP Publishing. ([1])
• Andres, R., Nikolov, A., & Brümmer, A. (2016). CFD Simulation of a Twin Screw Expander including Leakage Flows. In 23rd International Compressor Engineering Conference at Purdue, July 11-14, 2016. ([2])
• Willie, J. (2017, September). Use of CFD to predict trapped gas excitation as source of vibration and noise in screw compressors. In IOP Conference Series: Materials Science and Engineering (Vol. 232, p. 012021). IOP Publishing. ([3])

External Links

* TwinMesh Homepage
* CFX Berlin Homepage