In many industrial applications, such as HVAC systems and aerospace engineering, a fan inside a diffuser is essential for improving airflow and pressure recovery. The relationship between the stationary diffuser components and the revolving fan may have complicated flow patterns and turbulence. However, thanks to ANSYS Fluent solver and CFD techniques (MRF), a study is conducted to investigate fan effects placed inside a diffuser.

Simulation Process

The Diffuser zone and rotating fan are primarily modeled in SpaceClaim. There must be two distinct zones because the Reference Frame (MRF) module is going to be used, as the title implies. The meshing process is also of the essence. Avoiding cell size jumps between two zones is necessary. The fan works at 1440 rpm while the incoming air enters the diffuser by suction pressure.

Post-processing

Flow enters the diffuser with nearly 12m/s velocity magnitude, interacting with fan blades that are rotating at 1440 rpm. The Bernoulli equation implies a reduction in velocity and increased pressure instead of diffusers. Whereas in many industrial applications, a sudden drop in velocity could be disruptive. Thus, adding a fan before the diffuser area can support it. In our study, the outlet average temperature shows a mean value of 14 m/s. So not only has it not dropped, it effectively promoted.