CFD simulation

Computational fluid dynamics (CFD) process illustrated for an impeller

The starting point is the CAD model which exactly describes the component's three-dimensional geometry. This is made available to the CFD program and pre-processed to obtain a computation grid.

After specifying the inlet and outlet boundary conditions, the numerical calculation can begin. When the numerics have stabilised after a certain number of iterations, the solution is analysed and documented (post-processing).

If the results do not yet meet all the requirements, for example specifications for a new design, the CAD model must be modified, and the process is repeated from the start.

Design of a suction impeller

Because of the high peripheral speed of large boiler feed pumps, the suction (first) stage impeller must very often be kept completely cavitation-free. To achieve this, the vane leading edge must be optimised using computational fluid dynamics programs for low NPSHinc (incipient cavitation) values. The congruence between the computation and experiment is excellent.