- cp_aveAverage value of the specific thermal capacityC++ Type:PostprocessorName Unit:(no unit assumed) Controllable:No Description:Average value of the specific thermal capacity 
- gravity_magnitudeGravity vector magnitude in the direction of interestC++ Type:double Unit:(no unit assumed) Controllable:No Description:Gravity vector magnitude in the direction of interest 
- k_aveAverage value of the thermal conductivityC++ Type:PostprocessorName Unit:(no unit assumed) Controllable:No Description:Average value of the thermal conductivity 
- lCharacteristic distanceC++ Type:PostprocessorName Unit:(no unit assumed) Controllable:No Description:Characteristic distance 
- mu_aveAverage value of the dynamic viscosityC++ Type:PostprocessorName Unit:(no unit assumed) Controllable:No Description:Average value of the dynamic viscosity 
- rho_aveAverage densityC++ Type:PostprocessorName Unit:(no unit assumed) Controllable:No Description:Average density 
RayleighNumber
Postprocessor that computes the Rayleigh number for free flow with natural circulation
The Rayleigh number is computed as:
where:
- is the density difference between the warm and cool region 
- is the temperature difference between the warm and cool region 
- is the fluid expansion coefficient 
- is the size of the system in the direction of the temperature difference 
- is the magnitude of the gravity 
- is the dynamic viscosity of the fluid 
- is the thermal diffusivity of the fluid 
The density difference may be provided either directly or using the fluid expansion coefficient and the temperature difference. All quantities but gravity may be provided as postprocessors.
Input Parameters
- T_coldMinimum temperature, or cold source temperatureC++ Type:PostprocessorName Unit:(no unit assumed) Controllable:No Description:Minimum temperature, or cold source temperature 
- T_hotMaximum temperature, or hot source temperatureC++ Type:PostprocessorName Unit:(no unit assumed) Controllable:No Description:Maximum temperature, or hot source temperature 
- betaAbsolute value of fluid volumetric expansion coefficientC++ Type:PostprocessorName Unit:(no unit assumed) Controllable:No Description:Absolute value of fluid volumetric expansion coefficient 
- rho_maxMaximum densityC++ Type:PostprocessorName Unit:(no unit assumed) Controllable:No Description:Maximum density 
- rho_minMinimum densityC++ Type:PostprocessorName Unit:(no unit assumed) Controllable:No Description:Minimum density 
Optional Parameters
- allow_duplicate_execution_on_initialFalseIn the case where this UserObject is depended upon by an initial condition, allow it to be executed twice during the initial setup (once before the IC and again after mesh adaptivity (if applicable).Default:False C++ Type:bool Controllable:No Description:In the case where this UserObject is depended upon by an initial condition, allow it to be executed twice during the initial setup (once before the IC and again after mesh adaptivity (if applicable). 
- execute_onTIMESTEP_ENDThe list of flag(s) indicating when this object should be executed. For a description of each flag, see https://mooseframework.inl.gov/source/interfaces/SetupInterface.html.Default:TIMESTEP_END C++ Type:ExecFlagEnum Controllable:No Description:The list of flag(s) indicating when this object should be executed. For a description of each flag, see https://mooseframework.inl.gov/source/interfaces/SetupInterface.html. 
- execution_order_group0Execution order groups are executed in increasing order (e.g., the lowest number is executed first). Note that negative group numbers may be used to execute groups before the default (0) group. Please refer to the user object documentation for ordering of user object execution within a group.Default:0 C++ Type:int Controllable:No Description:Execution order groups are executed in increasing order (e.g., the lowest number is executed first). Note that negative group numbers may be used to execute groups before the default (0) group. Please refer to the user object documentation for ordering of user object execution within a group. 
- force_postauxFalseForces the UserObject to be executed in POSTAUXDefault:False C++ Type:bool Controllable:No Description:Forces the UserObject to be executed in POSTAUX 
- force_preauxFalseForces the UserObject to be executed in PREAUXDefault:False C++ Type:bool Controllable:No Description:Forces the UserObject to be executed in PREAUX 
- force_preicFalseForces the UserObject to be executed in PREIC during initial setupDefault:False C++ Type:bool Controllable:No Description:Forces the UserObject to be executed in PREIC during initial setup 
Execution Scheduling 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. 
- outputsVector of output names where you would like to restrict the output of variables(s) associated with this objectC++ Type:std::vector<OutputName> Controllable:No Description:Vector of output names where you would like to restrict the output of variables(s) associated with this object 
- use_displaced_meshFalseWhether or not this object should use the displaced mesh for computation. Note that in the case this is true but no displacements are provided in the Mesh block the undisplaced mesh will still be used.Default:False C++ Type:bool Controllable:No Description:Whether or not this object should use the displaced mesh for computation. Note that in the case this is true but no displacements are provided in the Mesh block the undisplaced mesh will still be used. 
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.