Evaluation of Computational Fluid Dynamics and Coupled Fluid-Solid Modeling for a Direct Transfer Preswirl System

Area of Science:

• Aerospace Engineering
• Computational Fluid Dynamics
• Heat Transfer

Background:

• Accurate prediction of preswirl cooling air delivery and rotor disk temperatures is vital for gas turbine cooling system performance.
• Assessing thermal stresses and ensuring rotor disk life assessment depend on reliable temperature predictions.

Purpose of the Study:

• To predict preswirl cooling air delivery and disk metal temperatures using computational fluid dynamics (CFD) and coupled finite element-CFD methods.
• To validate simulation results against experimental measurements from a direct transfer preswirl test rig.

Main Methods:

• Standalone 3D steady and unsteady computational fluid dynamics (CFD) simulations were performed.
• Coupled finite element-CFD (FE-CFD) analyses were conducted for integrated thermal prediction.
• CFD results were compared with experimental data, including cooling air temperatures and nozzle discharge coefficients.

Main Results:

• Predicted cooling air temperatures showed good agreement with experimental measurements.
• Nozzle discharge coefficients were under-predicted by the CFD models.
• Coupled FE-CFD analyses accurately predicted solid metal temperatures, considering modeling limitations.
• CFD-derived heat transfer coefficients on the rotor disk demonstrated temperature variation effects.

Conclusions:

• The coupled FE-CFD approach provides a reliable method for predicting rotor disk temperatures in gas turbine engines.
• Simulation results offer valuable insights into cooling system performance and thermal management.
• Further refinement of CFD models may improve the prediction accuracy of nozzle discharge coefficients.