Can we update multiple auxvariables at once from a single pluggable system ?

[KamalnathOSU]

Dear MOOSE team,

In my simulation, based on the thermo-mechanical history of each node, I am calculating a few properties like grain_size and yield strength on each node. I have an external C library which can calculate these properties ( Discussion: #24129 ). The API of the external C library allows to me calculate several properties at once (let's say five properties). I want to store all these properties in individual auxvariables. As the API calls are expensive, I dont want to call the API functions in five times in five different auxkernels for each timestep. Is there any alternative ?

[GiudGiud]

Hello

AuxKernels are meant to set the value of only one variable, so that would be one API call by variable

Would you want to use an array variable to store everything as components of variables?
The alternatives are:

• follow the same design as the SolutionUO, with one UO doing the reading and kernels being able to leverage what the UO has read without re-reading
• make a user object that sets the 5 variables in one go

Guillaume

[KamalnathOSU]

@YaqiWang I have never user Array variable before. Is there any example of its usage in heat_conduction (or) phase_field module which I can take a look ?

@lindsayad @GiudGiud As writable "writableCoupledValues" might be removed in future, I think I would with this option "make a user object that sets the 5 variables in one go". Can you point me towards some userobjects in MOOSE that assigns multiple AuxVariables ?

[YaqiWang]

I am not aware of examples of using array aux kernels in modules. But this FunctionArrayAux in MOOSE framework should give you an idea on how it works. You can search through inputs to find how FunctionArrayAux is used.

[lindsayad]

Oops I goofed on the name. There is getWritableCoupledVariables, writableVariable, and writableCoupledValue

[lindsayad]

Here's an example of a .C file and accompanying input file if you wanted to update nodal variables (e.g. Lagrange). You can add arbitrarily many coupled variables in your input parameters block

[KamalnathOSU]

@lindsayad Thank you. In the documentation, I saw that [writableCoupledValue] is(https://mooseframework.inl.gov/docs/doxygen/moose/classCoupleable.html#aae21e308b8620ce460b24a03cdb7e186) is deprecated. So I should go with writableVariable ?

[KamalnathOSU]

@lindsayad : Thank you again. I didn't see your last response on the example file *.C earlier.