How is CFD used in turbomachinery blade design?

CFD applications in blade design include: 2D blade section optimization (pressure distribution, loss minimization), Full 3D blade passage analysis with hub/tip effects, Multi-row simulations for stage interactions, Tip clearance flow and leakage modeling, Film cooling effectiveness, and Unsteady calculations for blade row interaction and noise. Methods progress from RANS (steady-state design) through time-accurate URANS to LES for detailed physics. Optimization uses adjoint methods for efficient gradient calculation with hundreds of design variables. Validation against cascade and rig testing ensures CFD accuracy. Modern design achieves target efficiency within 1% with CFD-led development, reducing expensive testing.