Biomedical Engineering Reference
In-Depth Information
Reproduced with permission. Copyright retained by Inderscience Publishers.
Figure 28. A Sample Residual Plot of Continuity, x-, y-components of Velocity,
Energy, and k-direction Vector.
Typical discretization schemes include:
a)Finite-difference methods;
b)Volume methods;
c)Finite-element methods;
d)Boundary-integral methods; and
e)Special methods;
These methods convert the differential equations into coupled algebraic
equations that can then be solved by the solver to obtain numerical solutions.
Theoretically, the Navier- Stokes' equations should result in a null value, the
difference between the numerical solution obtained and zero is gives the
residual value. Hence, the residuals are a manner of understanding the
magnitude of the error in the CFD model. The numerical solutions obtained
are approximate solutions and not exact solutions. Discretization methods
involve a high level of mathematical understanding and are beyond the scope
of this paper.
Meshing of the CFD Model
In addition to constructing the mesh for the model gun, the analytical
mesh has to move in accordance with the calculated ball motion. Dynamic
mesh motion is a standard part of the software and the volume immediately
around the ball was defined to move with it. Most of the barrel was modelled
