Blade Film Cooling

Blade Film Cooling — ANSYS Fluent CFD Simulation

Description

This project simulates film cooling on a gas turbine blade — the technique that lets turbine blades survive gas temperatures well above their material limits by holding a thin layer of cool air against the surface. The cooling air, bled from the compressor stage, is fed through internal channels and ejected through discrete holes to form a protective film over the blade. Because the hot gas, the cooling air, and the solid blade all exchange heat simultaneously, this is a demanding coupled thermal-fluid problem that brings together everything learned earlier in the package. As the capstone of the Heat Transfer: Beginner CFD Training Package, it represents the kind of advanced turbine-cooling analysis that professional CFD engineers carry out in industry.

Methodology

The study is set up as a conjugate heat transfer (CHT) problem: the fluid domain (hot gas and cooling air) and the solid blade are coupled at the walls, so heat conducts through the blade while the external hot gas and the internal and film cooling air exchange heat with it simultaneously. Turbulence is modeled with k-ω SST, which resolves both the near-wall film behavior and the free-stream mixing between the cool and hot streams. The geometry is built in Design Modeler and meshed in ANSYS Meshing, then converted to a polyhedral mesh of roughly 2.7 million cells in ANSYS Fluent for better gradient resolution and faster convergence around the cooling holes.

Analysis

Pathlines trace the cooling air through the blade's internal channels and out through the film holes, where it forms a thin thermal barrier over the surface. The film thickness varies along the blade — thickest near the holes — and the film is turbulent, mixing with the hot gas downstream and progressively losing effectiveness. The simulation makes the core design trade-off visible: hole size, shape, spacing, count, and injection angle all control how well the film holds before the hot gas entrains it. By the end of the project, you will be able to set up a coupled fluid–solid CHT model, mesh and inject through discrete cooling holes, choose and justify k-ω SST for film flows, and read film effectiveness from temperature fields and pathlines.