We can derive a theoretical form for the permeability in a simple situation. Consider the rectangular block of length L, and sides of length s, that has n cylinders of diameter d0, drilled through it...

We can derive a theoretical form for the permeability in a simple situation. Consider the rectangular block of length L, and sides of length s, that has n cylinders of diameter d0, drilled through it as shown in Figure P2.3. For a given pressure difference between the two ends, the volumetric flow rate through one of the cylinders is given by:

and through all of them by:

a. Derive an expression for the permeability, k.

b. What is the void fraction of the material and can you express the permeability in terms of the void fraction?