Discussion Forum

Good morning,

We are French students in thermal engineering, and we use Comsol at school for a research project. We need to use some experimental points in our model, we can’t create available functions for these data and so we hope to use a linearisation method. We don’t know how to do this and hope you can help us. I will try to be as clear as possible.

We have a spreadsheet of data defined by two variables. In practical terms, the data are pressure values P depending on temperature values T (three columns : 10°C, 30°C, 50°C) and depending on mass percentage values XM (lines : from 0 to 1 % by 0,1%). We obtained those pressures values by experimentation of a particular fluid.

Our simulation in Comsol simulates temperature and mass percentage values, we would like to have the pressure value by interpolation (actually a double interpolation). For example, on a time t1 and on a point (x1,y1), we have (T,XM)(1)=(14°C, 3.5%) : the interpolation must be done between the values [10°C : 50°C] and then between [3% : 4%].

My questions are these : Is it possible in Comsol (3.5a or else) to:
Use a table of data (with two variables) ?
Interpolate twice ?

If not, this operation could be done using Matlab: is it possible to run the two programs together ? The matlab function could be declared as an expression in Comsol, to be used in each point, at any time of the simulation.

Thank you.