Thermal-Fluid-Solid Coupling-Parametrical Numerical Analysis of Hot Turbine Nozzle Guide Vane

Area of Science:

• Turbomachinery
• Computational Fluid Dynamics (CFD)
• Heat Transfer

Background:

• Hot turbine components require advanced cooling for durability.
• Leading/trailing edges of turbine blades face corrosion and fatigue.
• Accurate thermal load prediction is vital for nozzle guide vane life assessment.

Purpose of the Study:

• To resolve inconsistencies in turbine vane cooling simulations due to unspecified coolant temperatures.
• To investigate the impact of various k-ω SST model options on thermal predictions.
• To analyze the effect of turbulent Prandtl number variations on cooling performance.

Main Methods:

• Utilized a fine mesh model with room inlet temperature for all cooling channels.
• Examined k-ω SST (shear-stress transport) model features: Viscous Heating (VH), Curvature Correction (CC), Production Kato-Launder (KT), Production Limiter (PL).
• Modified turbulent Prandtl number using Wassel/Catton and Kays/Crawford correlations and compared one, two, and four-equation viscosity models.

Main Results:

• Viscous heating (VH) was the most significant factor, increasing local vane temperature by up to 40°C.
• Turbulent Prandtl number variations also showed notable impact on thermal load predictions.
• Different viscosity models yielded varying results, highlighting the importance of model selection.

Conclusions:

• The study provides a more consistent approach to simulating turbine vane cooling.
• Viscous heating is a critical parameter that must be accurately accounted for in CFD simulations.
• Further research into optimal turbulent Prandtl number and viscosity models is warranted for improved turbine component life prediction.