Centrifugal Blower: MRF

Centrifugal Blower (MRF) — ANSYS Fluent CFD Simulation

Description

Welcome to the Centrifugal Blower CFD Simulation module. This project explores the design and analysis of a centrifugal blower using ANSYS Fluent and the Multiple Reference Frame (MRF) approach. A centrifugal blower raises the pressure of a gas by flinging it outward with a rotating impeller and collecting it in a surrounding volute — a configuration found throughout HVAC systems, industrial ventilation, and dust-collection equipment. The challenge in simulating it is representing the spinning impeller alongside the stationary volute, which is exactly what the MRF method makes possible. As the opening project of the Rotary Equipment: Beginner CFD Training Package, it introduces the MRF approach in its simplest single-rotor form — the foundation for the rotating-machinery cases that follow.

Methodology

The core of the setup is the MRF approach for modeling rotating machinery, which divides the domain into a rotating zone around the impeller and a stationary zone for the volute. The rotating and stationary zones are defined and the interface between them is configured so the flow transitions smoothly from one to the other. The impeller is assigned its rotational speed, and appropriate boundary conditions are applied at the blower inlet and outlet. This arrangement captures the interaction between the impeller and the volute — including the flow near the volute tongue — while keeping the solution steady through the reference-frame approximation rather than physically rotating the mesh.

Analysis

Post-processing focuses on the flow field within the blower. Three-dimensional velocity fields reveal the flow patterns and vortex structures developing within the rotating impeller, while pressure contours show the pressure recovery through the volute and the overall pressure rise the blower delivers. From these results you can evaluate the fundamental pressure–flow relationship, estimate the blower's efficiency, and study how the impeller and volute flows interact. The setup also supports exploring how rotational speed affects performance and generating performance curves across operating conditions. By the end of this project, you'll be able to set up a rotating-machinery simulation using the MRF method, define rotating and stationary zones and their interface, assign rotational speed, and interpret the velocity and pressure fields to evaluate centrifugal blower performance for HVAC and industrial ventilation applications.