Dear Dinuka

There are traditional methods based on non-dimensional parameters to model them. You can find these methods in text-books (e.g. in HEDH there is one).

For designing a thermal wheel you should calculate these parameters for your case (inlet and outlet temperature and mass flow rate of hot and cold streams):

+ Inner and outer diameter of wheel

+ Length of wheel

+ Porosity of it

+ Rotational speed

+ Matrix material (Cp, conductivity, density)

+ And some other parameters (e.g. ratio of hot area (its default is 50%), ratio of flow area to total cross section area, ...)

You may consider different leakage flows by calculating them or simply assuming a value for them.

You can find various designs for a specific case satisfying your thermal duty. However, each of them may differ in pressure drop, weight, and other important features. So you may need an optimization or at least choosing the best option among a dozen of designs. Obviously, your optimized thermal wheel may be different based on your cost function (your goal).

You can read my article here:

Article Optimization of a three-layer rotary regenerator using genet...

Its references may also help you.