SCMMixingConstantBeta

Class that models the turbulent mixing coefficient beta as a user defined constant.

Overview

This closure class is used when the user wants to define a constant mixing coefficient for the whole subchannel assembly.

Calibrated parameter values

has been calibrated for quadrilateral assemblies using data from the 2x3 air-water facility that was operated by Kumamoto university. The purpose of that facility was to quantify the effects of mixing and void drift Sadatomi et al. (2004). In these experiments, the turbulent mixing rates and the fluctuations of static pressure difference between subchannels were measured. The author derived a way to use the die concentration measurements, in order to calculate the turbulent mixing rates () between subchannels Kawahara et al. (1995). Additional Information about the use of can be found in Turbulent crossflow.

It is important to note that the mixing coefficient is simply a tuning parameter that will depend on the specific geometry of the facility being modeled. This facility is a square lattice, but the geometry is much larger than that of a typical PWR pin-lattice geometry. Nevertheless this study is useful for showing that the code is capable of predicting the correct mixing rate if it is calibrated correctly.

After calibrating the turbulent diffusion coefficient we turned our attention to the turbulent modeling parameter . This is a tuning parameter that informs on how much momentum is transferred/diffused between subchannels, due to turbulence. The CNEN 4x4 test Marinelli et al. (1972) performed at Studsvik laboratory for studying the flow mixing effect between adjacent subchannels was chosen to tune this parameter. This experiment consists in velocity and temperature measurements taken at the outlet of a 16-pin assembly test section. Analysis of the velocity distribution at the exit of the assembly can be used to calibrate the turbulent parameter . Additional Information about the use of this parameter can be found in Turbulent momentum transfer.

For quadrilateral assemblies, the calibration values computed were: , Kyriakopoulos et al. (2022).

Input Parameters

  • betaTurbulent mixing parameter [-].

    C++ Type:double

    Unit:(no unit assumed)

    Controllable:No

    Description:Turbulent mixing parameter [-].

Required Parameters

  • CT1Turbulent momentum, modeling parameter [-].

    Default:1

    C++ Type:double

    Unit:(no unit assumed)

    Controllable:No

    Description:Turbulent momentum, modeling parameter [-].

Optional Parameters

  • control_tagsAdds user-defined labels for accessing object parameters via control logic.

    C++ Type:std::vector<std::string>

    Controllable:No

    Description:Adds user-defined labels for accessing object parameters via control logic.

  • enableTrueSet the enabled status of the MooseObject.

    Default:True

    C++ Type:bool

    Controllable:Yes

    Description:Set the enabled status of the MooseObject.

Advanced Parameters

  • prop_getter_suffixAn optional suffix parameter that can be appended to any attempt to retrieve/get material properties. The suffix will be prepended with a '_' character.

    C++ Type:MaterialPropertyName

    Unit:(no unit assumed)

    Controllable:No

    Description:An optional suffix parameter that can be appended to any attempt to retrieve/get material properties. The suffix will be prepended with a '_' character.

  • use_interpolated_stateFalseFor the old and older state use projected material properties interpolated at the quadrature points. To set up projection use the ProjectedStatefulMaterialStorageAction.

    Default:False

    C++ Type:bool

    Controllable:No

    Description:For the old and older state use projected material properties interpolated at the quadrature points. To set up projection use the ProjectedStatefulMaterialStorageAction.

Material Property Retrieval Parameters

Input Files

References

  1. Akimaro Kawahara, Michio Sadatomi, Yoshifusa Sato, and Eiichi Shiga. Treatment of turbulent mixing rate in a two-phase subchannel flow. for developing flow without pressure differential between subchannels. Nippon Kikai Gakkai Ronbunshu, B Hen, 61(583):861–867, 1995.[BibTeX]
  2. Vasileios Kyriakopoulos, Mauricio E Tano, and Jean C Ragusa. Development of a single-phase, transient, subchannel code, within the moose multi-physics computational framework. Energies, 15(11):3948, 2022.[BibTeX]
  3. V Marinelli, L Pastori, and B Kjellen. Experimental investigation on mass velocity distribution and velocity profiles in an lwr rod bundle. Trans. Amer. Nucl. Soc., 15(1):413, 1972.[BibTeX]
  4. M. Sadatomi, A. Kawahara, K. Kano, and Y. Sumi. Single- and two-phase turbulent mixing rate between adjacent subchannels in a vertical 2x3 rod array channel. International Journal of Multiphase Flow, 30(5):481–498, 2004.[BibTeX]