CFD SUPPORT introduces the new generation of CFD simulations. TCFD brings an extreme increase of productivity to CFD simulations. TCFD is extremely popular project, because it successfully merged benefits of an open-source (perpetual, unlimited users, jobs, and cores, customizable, …) with benefits of commercial codes (professional support, well tested, ready for the industry, robust, accurate, automated, GUI, …).
TCFD is fully automated, it can run the whole workflow by a single command: data input, new case is written down, mesh is created, case is set-up, case is simulated, results are evaluated and the results report is written down. Both GUI and batch mode. Data in – data out. TCFD is mainly focused on supporting the engineers in their real value added work. TCFD is fully automated and the beauty of TCFD is that it is the user who decides how deep to dive into a CFD or not at all. And all the options remain open at the same time.
The Input Data & the Mesh
The pump model is converted from the external .msh mesh format to OpenFOAM® mesh format. This tutorial is computed as a periodic segment. The mesh has four individual components: the inlet tube, rotor part, stator partand the outlet part. Each component has its own mesh. All the meshes are merged into one mesh and they are connected with the interfaces. In Turbomachinery CFD, any number of model components is allowed.
Periodic segment or not?
The computational mesh can be used as a whole impeller as well as a single blade periodic segment. There can be also any combinanation of periodic and whole components. The only condition is the interfaces should match at the hub and shroud. Periodic segment approach can save reasonable amount of the mesh cells. That is resulting in reduction of simulation CPU time. The full impeller approch is more robust. And also full impeller allows the transient simulation on the same mesh.
The component graph
Any project simulated in TCFD has its component graph. The component graph shows how the components are organized – the model topology. What is the inlet, the outlet and how the components are connected via interfaces.
CFD Simulation Set-up
Incompressible flow model
Steady-state flow model
Medium: Water
Viscosity: ν = 8.899e-7 [m2/s]
Rotation speed: 294 [RPM]
Flow Rate: 14 [m3/s]
Interface: mixingInterface (radial averaging)
Turbulence Model: k-ω SST
Mesh: external hexa mesh
Mesh Cells (segment): 210580
Mesh Average y+: 100 [-]
CPU time (segment): 8 [core.hours]
For more details of CFD Simulation Set-up see TCFD Manual.
Running CFD Simulation
The simulation can be run on any number of parallel processors. Immediately after the simulation is started the user can watch the progress of all the important quantities: flow rates, residuals, efficiency, torque or pressure difference. This run-time function gives the user valuable information of the convergence and also the availability to stop the simulation before its standard end. The current results and the .html results report can be updated anytime during the simulation run.
The visual simulation results are watched in ParaView (included in any OpenFOAM distribution). ParaView is CFD postprocessing tool providing all standard features for analyzing CFD data.
CFD Support developed a special extension to ParaView for postprocessing of rotating machinery: Turbo Blade Post. It is special a set of special filters for ParaView to enable for example blade-to-blade view, or meridional average view. Turbo Blade Post detailed manual is available on-line: Turbo Blade Post Manual
Turbo Blade Post can create Blade to Blade view, display surface LIC on surfaces – the streamtraces in the plane. Turbo Blade Post allows displaying relative velocity, it can explore the angle of attack at the leading edge. The same at the trailing edge.
Within Turbo Blade Post the machine parts can be unwrapped to be able to slice the computed quantities at the same height along the blade. Within such a unwrapped mesh it is also possible to plot quantities around the blade at the certain height. Another Turbo Blade Post function is Meridional Average which creates a meridional plane of circumferential averages of simulated quantities.