Centrifugal Compressor

Centrifugal Compressor — ANSYS Fluent CFD Simulation

Description

Welcome to the Centrifugal Compressor CFD Simulation module. This project explores the design and analysis of a centrifugal compressor using ANSYS Fluent, examining the aerodynamics within one of the most important components in turbomachinery. A centrifugal compressor raises the pressure of a gas by accelerating it through a rotating impeller and then recovering that energy as pressure in a diffuser. Unlike a low-speed blower, a compressor operates at high speed where the gas density changes significantly, making it a compressible-flow problem with coupled pressure and temperature fields. Within the Rotary Equipment: Beginner CFD Training Package, this project introduces compressible flow in rotating machinery, stepping up from the incompressible blower and fan cases toward true high-speed turbomachinery.

Methodology

Because the flow is compressible, the setup solves the governing equations for compressible flow with a turbulence model suited to high-speed rotating flow. The rotation is handled with the Multiple Reference Frame (MRF) approach for steady-state analysis, dividing the domain into a rotating zone around the impeller and a stationary zone for the diffuser, with the interface between them configured for a smooth flow transition. The impeller is assigned its rotational speed, and the boundary conditions are set to represent the compressor's operating conditions. This arrangement captures the flow through the rotating impeller passages and the pressure recovery in the diffuser, resolving both the aerodynamic and thermodynamic behavior of the stage.

Analysis

Post-processing focuses on the pressure and temperature fields that define compressor performance. Three-dimensional pressure contours reveal how pressure builds through the impeller and diffuser, while temperature contours show the thermodynamic response of the compressed gas. From these results you can compute the key performance metrics — the total-to-total pressure ratio and the isentropic efficiency — and study the flow through the impeller passages and diffuser. The setup also supports exploring how rotational speed affects performance across operating conditions. By the end of this project, you'll be able to set up a compressible rotating-machinery simulation using the MRF method, resolve the coupled pressure and temperature fields, and interpret the results to evaluate centrifugal compressor performance for aerospace propulsion and industrial process applications.