Hello everyone, I have some confusion in the document "Simple convection in a quarter of a 2d annulus".
The first question is why we only set the values of the thermal expansion coefficient and viscosity of the material in the material model here, unlike the reference density, reference specific heat capacity, reference temperature and heat conductivity of the material which are set in "Convection in a 2d box".
The second puzzle is that we only have the name of the gravity model but we don't have a value for the acceleration of gravity
Hi @ddarkerlu,
The first question is why we only set the values of the thermal expansion coefficient and viscosity of the material in the material model here, unlike the reference density, reference specific heat capacity, reference temperature and heat conductivity of the material which are set in “Convection in a 2d box”.
The parameters that are not specified in the prm file for the Simple material model are set their default values, which can be found here in the manual or in the file parameters.prm located in the output folder. The viscosity and thermal expansion coefficient in this case are specified as the listed values are different than the defaults.
The second puzzle is that we only have the name of the gravity model but we don’t have a value for the acceleration of gravity
In this case the gravity model is taken from an ascii file. As no other ascii file is specified, the default ascii file is used. The details of this can be found in the manual here.
I hope this helps.
John
Thank you very much for your answer to my question, wish you have a happy day!