Thermo Mechanical Optimization of Cooled Turbine Vane

Abstract

This paper discuses the problem of cooling system optimization within a gas turbine vane regarding to thermo-mechanical behaviour of the component. The analysis involves the optimization of location and size of internal cooling passages within the vane. Cooling is provided with ten circular passages and heat is transported by convection. The task is approached in 3D configuration. Each passage is fed with cooling air of constant parameters at the inlet. Also a constant pressure drop is assumed along the passage length. The thermal boundary conditions in passages varied with diameter and local vane temperature (passage wall temperature). The analysis is performed by means of the genetic algorithm for the optimization task and FEM for the heat transfer predictions within the component. In the present study the vane profile is taken as aerodynamically optimal and the objective of the search procedure is to find cooling structure variant that at given external conditions provides possibly low stresses and material temperature.

Optimization of blade cooling system with use of conjugate heat transfer approach

“…The task was already solved in Refs. [25] and [27], but without CHT calculations. Technically, it requires the involvement of compatible FEM software which will make it possible to determine the stress field in the blade on the basis of the solution to the temperature field in the RCHT task.…”

“…They analyzed part of a rectangular channel of fixed size where the aim was to select the optimal dimensions and distance between neighboring ribs in terms of heat exchange. Nowak and Wroblewski [27] presented the optimization of location and side of internal cooling passages whose shape was circular and their number was fixed. In this research the passages could freely move within the domain by satisfying the thermo-mechanical criteria for a 3D configuration.…”

Optimization of an airfoil cooling system using a Pareto dominance approach

“…In this case the approach was that the cooling holes could move freely in the blade cross-section with feasibility criteria retained. In later works (Nowak et al 2007(Nowak et al , 2008) the problem of channel optimization was expanded to a multidisciplinary task including thermal and strength states with relation to economic criteria. The latest work of Verstraete et al (2008) presents attempts to connect cooling channel optimization tasks with the thermal flow conjugated task.…”

“…Modification of the individuals due to the evolution within the global Cartesian system leads to a very high fraction of the population to violate the constraints. That is why the variables describing the channel are defined in a local curvilinear coordinate system, (Nowak and Wróblewski 2007). In this case the axis of abscissa follows the airfoil's suction side and the axis of ordinates is always perpendicular to it.…”

Thermal Analysis of a Film Cooling System with Normal Injection Holes Using Experimental Data

“…To predict the life and safety of hot components such as combustors, vanes, and blades, it is necessary to estimate the metal temperature of the film cooling system in an appropriate thermal environment. In recent years, several investigators [10][11][12] have attempted a conjugated analysis of heat conduction in turbine blades. In these conjugate analyses, blade surface temperatures and thermal stresses are predicted.…”