Radial Flow Between two Parallel Discs - Newtonian Model

5 Radial Flow Between two Parallel Discs — Newtonian Model 

Radial flow between parallel discs is a very common flow type encountered in polymer processing, particularly during injection mold filling. In this section, we seek the velocity profile, flow rates and pressure for this type of flow using the notation presented in Fig. 5.16. 

Let us consider a Newtonian fluid that is flowing due to a pressure gradient between two parallel disks that are separated by a distance 2h. The velocity and pressure fields that we will solve for are ur = ur z, r) and p = p(r). According to the Newtonian fluid model, 

Neglecting the inertia effects, the momentum equation becomes, 

This equation can be integrated, because the pressure is only a function of r. The constants of integration can be solved for by using the following boundary conditions 

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