- 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.
SCMHTCGnielinski
Class that computes the convective heat transfer coefficient using the Gnielinski correlation.
The HTC closure models inherit from: SCMHTCClosureBase.
Gnielinski Correlation for Turbulent Nusselt Number
Gnielinski extended the results of the significant work done by Petukhov to the transition Reynolds number by making small adjustments of the terms of the Petukhov correlation. A modified Gnielinski correlation for low Prandtl numbers is proposed here for calculating the Nusselt number for transitional and turbulent flows. The baseline correlation is presented originally here Gnielinski (1975) as well as in chapter 10 of Todreas and Kazimi (2021). The modified correlation reads as follows:
where:
: Nusselt number
: Reynolds number
: Prandtl number
: The friction factor for turbulent flow. Here we use the local subchannel friction factor.
A key modification in the correlation as implemented in SCM is the addition of to the Prandtl number. This modification retains predictions within experimental uncertainty at high numbers but enables the correlation to be used at low numbers. With this modification, at low numbers (approximately for ), one can expect behavior similar to that of the Lubarsky and Kaufman correlation Lubarsky and Kaufman (1955). It has an expanded range applicable for . This modified Gnielinski correlation reduces to the canonical Gnielinski correlation as Pr increases, which can be used for coolants (liquids/gases) in the range .
The effect of pipe length flow development and fluid property variations has not been considered in this implementation.
Denominator Flooring at Low Prandtl Numbers
At very low (e.g., liquid sodium, ), the term in the denominator approaches . Once the friction factor is large enough to be routinely encountered near the laminar-turbulent transition, the denominator can cross zero, causing to become unbounded or change sign. Since this regime is within the correlation's documented valid range (), it is not user misuse but a genuine singularity of the modified correlation. To keep physically bounded, the denominator is floored at so that instead saturates near the flat, conduction-dominated behavior that the low- flattening above is intended to produce. A solution warning is flagged whenever this floor is engaged.
Input 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
References
- Volker Gnielinski.
Neue gleichungen f"ur den w"arme-und den stoff"ubergang in turbulent durchstr"omten rohren und kan"alen.
Forschung im Ingenieurwesen A, 41(1):8–16, 1975.[Export]
- Bernard Lubarsky and Samuel J Kaufman.
Review of experimental investigations of liquid-metal heat transfer.
Technical Report, National Advisory Committee for Aeronautics, 1955.[Export]
- Neil E Todreas and Mujid S Kazimi.
Nuclear systems volume I: Thermal hydraulic fundamentals.
CRC press, 2021.[Export]