Recent developments in gas turbine component temperature prediction methods, using computational fluid dynamics and optimization tools, in conjunction with more conventional finite element analysis techniques

Journal of Engineering for Gas Turbines and Power

et al. 2013

The prediction of the preswirl cooling air delivery and disk metal temperature are important for the cooling system performance and the rotor disk thermal stresses and life assessment. In this paper, standalone 3D steady and unsteady computation fluid dynamics (CFD), and coupled FE-CFD calculations are presented for prediction of these temperatures. CFD results are compared with previous measurements from a direct transfer preswirl test rig. The predicted cooling air temperatures agree well with the measurement, but the nozzle discharge coefficients are under predicted. Results from the coupled FE-CFD analyses are compared directly with thermocouple temperature measurements and with heat transfer coefficients on the rotor disk previously obtained from a rotor disk heat conduction solution. Considering the modeling limitations, the coupled approach predicted the solid metal temperatures well. Heat transfer coefficients on the rotor disk from CFD show some effect of the temperature variations on the heat transfer coefficients. Reasonable agreement is obtained with values deduced from the previous heat conduction solution.

Section: Operating Conditionsmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

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

Javiya¹,

Chew²,

Journal of Engineering for Gas Turbines and Power

et al. 2013

“…The latter are tuned to match the engine test measurements. The stand-alone FE model "model matching" procedure is described by Dixon et al in [18]. The Rolls-Royce finite element solver SC03 is employed for solid domain thermal analysis.…”

Section: Solid Domainmentioning

confidence: 99%

Coupled Fluid-Structure Transient Thermal Analysis of a Gas Turbine Internal Air System With Multiple Cavities

Ganine

Javiya

Journal of Engineering for Gas Turbines and Power

et al. 2012

This paper presents the transient aero-thermal analysis of a gas turbine internal air system through an engine flight cycle featuring multiple fluid cavities that surround a HP turbine disk and the adjacent structures. Strongly1 γ least-squares problem solution ∆ difference δ wall temperature perturbation factor θ time discretization control parameter Superscripts () n n-th time step INTRODUCTIONAccurate prediction of aerodynamic, aero-mechanical and thermo-mechanical phenomena attracts an increasing interest from the gas turbine industry. Efficient and robust analysis procedures able to properly describe the thermal and flow environment within a secondary air system may lead to substantial gains in overall engine performance, weight and components reliability by offering improved means of optimizing designs [1].Typically, in thermal modeling, the internal air system is modeled with user-specified boundary conditions, while more accurate CFD predictions, if available, are applied only on some portions of the system. The user-specified boundary conditions rely heavily on correlations, they require a significant effort from an end-user to correctly represent the complex physical phenomena over a wide range of operating conditions. As the geometries of modern air systems grow in complexity, current models with correlations become painful to build and increasingly obsolete.A general trend in computational modeling of modern turbo-machinery systems is to move towards the "virtual" or "whole" engine simulation [2]. As far as modeling of the internal air systems is concerned, a natural and incremental advance in both the complexity and the accuracy of current modeling is to include and interconnect multiple CFD domains within a single simulation. Among the advantages it may offer are a lower level of human intervention and time required to set up the models, and more importantly, automatic generation of the boundary conditions for the downstream components. However, this comes at a price of a considerably higher computational effort required to run a simulation through an engine transient flight cycle leading to long analysis times.Many studies in recent years sought to improve the predictive capabilities of thermo-mechanical analysis codes by coupling FE solvers to detailed CFD models of individual components to more accurately evaluate wall temperature distribution in turbine cavities, see, for example, [3,4,5,6,7]. While these studies were able to obtain only a general agreement with the experimental data, they did demonstrate many of the fundamental features outlined in earlier investigations. Subsequent efforts attempted to further improve the agreement by including some of both fluid and solid domains 3D geometrical features in the analysis [8] or the effects of solid domain thermo-mechanical distortion on flow dynamics [9]. Still, accurate and automatic predictions of heat transfer in the internal air systems remain a difficult challenge.The main goal of this paper is to provide a snapshot of the state-...

“…In typical engine tests, the thermocouple uncertainties are about 5K for steady and 10K for transient conditions [1]. Hence, the time stepping accuracy was specified as 2.5K in the coupled solutions.…”

Section: Fe Modelmentioning

confidence: 99%

“…The figure also shows the engine test data. These measurements were obtained from an engine development test for the transient cycle in figure 3, as discussed, for example, by Dixon et al [1]. In this plot, it is difficult to observe the difference between calculated and engine test temperatures.…”

Section: Temperature Predictionmentioning

confidence: 99%

Coupled FE–CFD thermal analysis for a cooled turbine disk

Javiya

Chew

Proceedings of the Institution of Mechanical Engineers, Part C:

et al. 2015

This paper presents transient aero-thermal analysis for a gas turbine disk and the surrounding air flows through a transient slam acceleration/deceleration "square cycle" engine test, and compares predictions with engine measurements. The transient solid-fluid interaction calculations were performed with an innovative coupled finite element (FE) and computational fluid dynamics (CFD) approach. The computer model includes an aero-engine high pressure turbine (HPT) disk, adjacent structure, and the surrounding internal air system cavities. The model was validated through comparison with the engine temperature measurements and is also compared with industry standard standalone FE modelling. Numerical calculations using a 2D FE model with axisymmetric and 3D CFD solutions are presented and compared. Strong coupling between CFD solutions for different air system cavities and the FE solid model led to some numerical difficulties. These were addressed through improvement to the coupling algorithm. Overall performance of the coupled approach is very encouraging giving temperature predictions as good as a traditional model that had been calibrated against engine measurements.