SCMMixingChengTodreas

Class that models the turbulent mixing coefficient for wire-wrapped triangular assemblies using the Cheng Todreas correlations.

Overview

This closure class is used to model the turbulent mixing coefficient using the Cheng and Todreas correlations. Specifically this closure model applies to triangular assemblies with wire-wrapped pins. The implementation was based on:

  • Hydrodynamic models and correlations for bare and wire-wrapped hexagonal rod bundles—bundle friction factors, subchannel friction factors and mixing parameters, Cheng and Todreas Cheng and Todreas (1986).

The implementation separates the two Cheng-Todreas uses of :

  • interior gaps use the base turbulent mixing parameter in the global turbulent crossflow relation ;

  • edge/corner gaps return a sweep-flow parameter only when the subchannel enthalpy equation asks for sweep_flow = true; this sweep-flow term is applied separately in the triangular-assembly energy equation and is not added to the base turbulent crossflow parameter.

The closure flags a solution warning when , , number of pins, or is outside the data range used for the Cheng-Todreas wire-wrapped mixing correlation.

In the intermittent regime, the original Cheng-Todreas treatment has been simplified in this implementation. The interpolation factor is evaluated as

using the bulk transition limits

These bulk and values are used for both the base turbulent mixing parameter and the peripheral sweep-flow parameter.

Information about the use of can be found in Turbulent crossflow. Additionally, the user may opt to provide the turbulent momentum mixing parameter CT. Information about the use of this parameter can be found in Turbulent momentum transfer.

Input 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. Shih-Kuei Cheng and Neil E Todreas. Hydrodynamic models and correlations for bare and wire-wrapped hexagonal rod bundles—bundle friction factors, subchannel friction factors and mixing parameters. Nuclear engineering and design, 92(2):227–251, 1986.[BibTeX]