Two-phase CFD model of the MYRRHA-FASTEF primary coolant loop including all relevant thermal aspects

The aim of this report is to describe the work performed to develop a comprehensive CFD representation of the MYRRHA primary loop. The structure of the CFD geometry is described as well as the physical modelling. The model includes the free surfaces dynamics of the LBE and is transient in nature. A simulation with 6 million control volumes and restricted to the fluid domain has been run, reaching nominal condition starting from the fluid at rest. The stability of the flow under nominal conditions is then been checked by monitoring the velocity and temperature field during 120s. It can be seen that under these conditions, the flow is quite well stabilized by the thermal stratification in the hot plenum. The flow in the cold plenum is not stationary but slowly oscillates around a mean configuration. A second model, taking into account the conjugate heat transfer with the structural part has been built and simulated. The second model is slightly larger with 9.3 million cells, one of with for the structural part. The simulation has been monitored for 300s and the results of the monitoring are presented and discussed. While the characteristic solid heat transfer time scale is too long to reach back a global thermal equilibrium in an affordable time, the main circulation is only marginally affected. A slight instability of one of the two primary pumps is however observed.

@Misc{Mor13b,
  author       = {Moreau, V.},
  title        = {Two-phase CFD model of the MYRRHA-FASTEF primary  coolant loop including all relevant thermal aspects},
  month        = {may},
  year         = {2013},
  note         = {EC EURATOM co-funded project SEARCH, Deliverable D5.3},
  type         = {Rapport de Contrat},
  keywords     = {CFD, MYRRHA, SEARCH, VoF, LBE},
  url          = {https://publications.crs4.it/pubdocs/2013/Mor13b},
}