Thermal Co-Simulation Tool
Overview
For certain types of thermal simulations, such as brake cooling or underhood thermal, the effects of conduction and radiation are important. Therefore, these effects should be included in the thermal simulations to improve the prediction accuracy.
For that purpose, a co-simulation framework has been developed to couple ultraFluidX and external thermal solvers. Currently, only the coupling of ultraFluidX and ThermoAnalytics TAITherm® is supported.
The role of the co-simulation tool is to manage the data transfer between two solvers during the simulation. At every coupling step, convection is solved by ultraFluidX from which heat transfer coefficient (HTC) and near-wall temperature are transferred to TAITherm as the boundary conditions. In turn, TAITherm returns the wall temperature to ultraFluidX by solving for conduction and radiation. The co-simulation tool will exit properly once ultraFluidX and TAITherm have finished successfully.
Use the Co-Simulation Tool
The co-simulation tool can be started via command line or custom scripts. All input information is passed directly as arguments in the command line, or indirectly as indicated in a script which is provided in the ultraFluidX tutorial folder.
As an input, a prepared ultraFluidX and TAITherm case is required. More information about setting up a thermal coupled simulation can be found in the ultraFluidX User Guide for thermal on <simulation><general>.
ultraFluidX-TAITherm coupling is part-to-part coupling. This means data exchange happens between a single part in ultraFluidX and a corresponding part in TAITherm. A part in ultraFluidX is coupled only if it has the temperature boundary condition and the name of the corresponding part in TAITherm is identical.
The co-simulation tool can be called from the command line with
>>co-sim <input_xml_file> <input_tdf_file> <arguments>
whereas <input_xml_file> and <input_tdf_file> are the input file of ultraFluidX and TAITherm, respectively.
- Specify the number of GPUs used by ultraFluidX
-ng [number_of_gpus]
- Specify the number of CPUs used by TAITherm
-n [number_of_cpus]
- Specify the output location of the results
-o [output_directory]
Result data, once the coupled simulation has been finished, is stored in the directory [output_directory]/co_simulation_results. If not specified, the result data is stored in [current_working_directory]/co_simulation_results.
- Specify type of coupling
-c [serial]
Currently, only [serial] coupling is supported, with which the TAITherm simulation is set as steady-state simulation.
- Specify the seed data in *.tdf
format
-s [TAITherm_seed_file]
The seed data should have part temperature profiles, which are used as initial conditions for TAITherm simulation. If not specified, the initial part temperature in the <input_tdf_file> is used for the initialization.
- Specify the set of selected parts in TAITherm that are used for
coupling
-p [part_id_file]
If specified, only parts whose TAITherm ID is listed in the [part_id_file] are coupled with the corresponding parts in ultraFluidX.
- Specify if the coupling data at every coupling step is stored for
post-processing
-e
If specified, the coupling data at each coupling step will be stored in the directory <co_simulation_results/coupling_results_x> with x being the number of the coupling step.