And then if I integrate it over the entire control surface, I'll get the net pressure force on that controlled surface. Similarly, you do it for viscous forces-- I won't write the details. And I'll just write this as F viscous with the recognition that we know that the viscous forces-- viscous shear, for instance-- is going to be related to the velocity gradients over there. And it's also going to be related to the question of viscosity. And we are assuming that the flow is Newtonian when we do that. Then we can write the aggregate view of F equal to ma as the net momentum outflow rate rho v.n times vdS is balanced by the forces on the control volume. So the pressure force is pndS, and then you have the viscous force on the control volume. And as before, this applies to any arbitrary surface within the flow domain. This is the form of momentum conservation that is used by the ANSYS FlueNt Solver. Now we have seen the equations that govern fluid flow and we need to add boundary conditions in. And we'll solve these equations using ANSYS FlueNt.

But before that, before we get into the CFD cases and actually solve these equations using ANSYS FlueNt, we need to have an idea of what is the strategy used by the FlueNt Solver to solve these equations. And it'll use the finite volume method. And the big idea is in CFD, I will discuss the strategy used in the finite volume method to solve these equations numerically. Don't go away.

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- Summer '18