Design and Optimization of the Internal Cooling Channels of a High Pressure Turbine Blade—Part I: Methodology

Abstract

This first paper describes the conjugate heat transfer (CHT) method and its application to the performance and lifetime prediction of a high pressure turbine blade operating at a very high inlet temperature. It is the analysis tool for the aerothermal optimization described in a second paper. The CHT method uses three separate solvers: a Navier–Stokes solver to predict the nonadiabatic external flow and heat flux, a finite element analysis (FEA) to compute the heat conduction and stress within the solid, and a 1D aerothermal model based on friction and heat transfer correlations for smooth and rib-roughened cooling channels. Special attention is given to the boundary conditions linking these solvers and to the stability of the complete CHT calculation procedure. The Larson–Miller parameter model is used to determine the creep-to-rupture failure lifetime of the blade. This model requires both the temperature and thermal stress inside the blade, calculated by the CHT and FEA. The CHT method is validated on two test cases: a gas turbine rotor blade without cooling and one with five cooling channels evenly distributed along the camber line. The metal temperature and thermal stress distribution in both blades are presented and the impact of the cooling channel geometry on lifetime is discussed.

An Error Indicator-Based Adaptive Reduced Order Model for Nonlinear Structural Mechanics—Application to High-Pressure Turbine Blades

“…Output:ω k ,x k , 1 ≤ k ≤ d 1 Initialization: Z = ∅, k = 0,ω = 0 and r 0 = g while r k 2 > g 2 do A reduced quadrature is also used to accelerate the integral computation in (6). The remaining integral computations in (5) are Ω f µ · ψ i and ∂Ω N T N,µ · ψ i . They do not depend on the current solution, but only on the loading of the online variability µ, which is no longer efficient for nonparametrized variabilities.…”

“…These blades are responsible for a large part of the maintenance budget of the engine, with temperature creep rupture and high-cycle fatigue [35,18] as possible failure causes. Various technological efforts have been spent to increase the durability of these blades as much as possible, such as thermal barrier coatings [43], advanced superalloys [10] and complex internal cooling channels [5,46], see Figure 1 for a representation of a high-pressure turbine blade. Figure 1: Illustration of a high-pressure turbine blade [1].…”

Performance Optimization in a Centrifugal Pump Impeller by Orthogonal Experiment and Numerical Simulation

“…Considerable effort has already been invested in studying the performance optimization in pump [4][5][6][7] and turbomachines [8][9][10]. There are various methods to optimize the design geometry, including global optimization algorithms based on heuristic algorithms and gradient-based methods.…”

Constructal design for gas-turbine blade based on minimization of maximum thermal resistance

“…The result showed that the FCE on the suction side was usually higher than that on the pressure side except the secondary vortices regions, and the upstream wakes could reduce the blade surface's FCE. Amaral et al [6] carried out the aerothermal analysis and optimization of a GTB based on the lifetime model, and the result showed that the blade lifetime could be extended by using the optimization procedure without increasing the amount of the cooling flow and the complexity of the cooling channel. Xu et al [7] employed a duplex-medium cooling method combining air and steam as coolants to investigate the cooling performance of a turbine vane, and the experimental result showed that the performance increased with the increases in the steam flow rate and coolant pressure, as well as the decrease in the coolant temperature.…”

“…Therefore, the cooling problems of the gas-turbine blade (GTB) should be specially paid attention, and many scholars have shown great interests in these problems [1][2][3][4][5][6][7][8][9].…”