Overview

At the Institute of Thermal Turbomachinery, the Hydraulic Turbomachinery working group is working intensively on increasing the efficiency of centrifugal fans. Due to the increasingly variable operation of fans in practice, high efficiency must also be ensured in partial and overload ranges. This operating range has so far eluded a closed numerical, predictive description, as different flow phenomena occur in the same geometry with different operating parameters, which must be reliably identified and their transition behavior recorded and described. The identification of the flow phenomena and their representation with the aid of suitable numerical models, the complementary verification and experimental validation form the main subject of the research.

Numerical flow simulation of the centrifugal fan

The numerical flow simulation only covers part of the overall system in order to keep the computational effort to a minimum. At the same time, the solution depends on a number of factors, such as the computational grid used, the turbulence model or the boundary and initial conditions. If the CFD simulations pass the valid comparison with the experimental data, this numerical model can be used to investigate flow phenomena, especially where measurement technology has no access (e.g. in the gap between the impeller and nozzle). In addition to the analysis of the flow, further optimization strategies can now be tested so that the desired increase in efficiency can be achieved as the overriding goal.