Conjugate Heat Transfer of an Internally Air-Cooled Nozzle Guide Vane and Shrouds

Xijia Wu,Leiyong Jiang,Zhong Zhang

doi:10.1155/2014/146523

Xijia Wu, Leiyong Jiang + Show 1 more

Open Access

https://doi.org/10.1155/2014/146523

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Abstract

In order to assess the life of gas turbine critical components, it is essential to adequately specify their aerothermodynamic working environments. Steady-state analyses of the flow field and conjugate heat transfer of an internally air-cooled nozzle guide vane (NGV) and shrouds of a gas turbine engine at baseline operating conditions are numerically investigated. A high-fidelity CFD model is generated and the simulations are carried out with properly defined boundary conditions. The features of the complicated flow and temperature fields are revealed. In general, the Mach number is lower and the temperature is higher on the NGV pressure side than those on the suction side. There are two high temperature regions on the pressure side, and the temperature across the middle section is relatively low. These findings are closely related to the locations of the holes and outlets of the cooling flow passage, and consistent with the field observations of damaged NGVs. As a technology demonstration, the results provide required information for the life analysis of the NGV/shrouds assembly and improvement of the cooling flow arrangement.

Highlights

Conjugate heat transfer (CHT) means the combined heat transfer processes between and in solid and fluid, where conduction usually dominates in solid and convection generally governs in fluid
The high-fidelity Computational fluid dynamics (CFD) model is created, and the simulations are performed with properly defined boundary conditions
The Mach number is higher, and the temperature is lower on the nozzle guide vane (NGV) suction side than those on the pressure side

Summary

Introduction

Conjugate heat transfer (CHT) means the combined heat transfer processes between and in solid and fluid, where conduction usually dominates in solid and convection generally governs in fluid. The CHT analysis has become an essential tool in the development and maintenance of thermal systems from aerospace, telecommunication, medicine, and atmosphere/ocean interaction to food processing. It can provide realistic 3D heat transfer analyses for practical complex devices, and this is why it has been extensively used in a wide range of applications to replace the traditional 1D semiempirical approach in CHT analyses. A higher temperature reduces the fatigue strength of the material, while a larger temperature gradient increases the thermal strain excursions and causes higher stresses Both of them can reduce the NGV fatigue life. For reliable life analysis of engine critical components, accurately assessing their aerothermodynamic working environments is essential

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