Hey everyone, I was hoping that I could get some confirmation on how to do splining for interpolation in two dimensions.
Recently I've been working on a project that deals with the vaporization of propane so the use of propane saturation properties have been of great importance. MathCAD has been super useful in this respect by using splining and interpolation functions on the data from propane tables to automate calculations. This has been relativeley easy by selecting either Pressure or Temperature as the independent variable and using the functions to curve fit to that.
However recently, I've began to toy with the idea of doing the same with superheated/compressed liquid data but that makes for a more daunting task since these regions have no relation between Pressure and Temperature and therefore the properties require both temperature and pressure specified to be determined. Therefore any property (eg enthalpy, entropy, density, etc.) is of the form z=f(x,y).
I've seen some examples of how to go about this type of multivariate interpolation in MathCAD but I'm having a bit of trouble making sense of exactly how to go about it. I'm hoping my reasoning can be validated by someone. Here is what I think the steps would be:
1) Supply a vector of Temperature as independent.
2) Supply a vector of Pressure as independent.
3) Supply a matrix of properties such that the i-j component of the matrix is a property at Temperature i, Pressure j
4) Use the augment function on the matrix
5) Use a splining function on the matrix and the (x y) column vector.
6) Use the interpolation function with those values.
Is this close to what should be going on? Anyone have some other examples?
I appreciate the help in advance!
