Numerical Study of the Heat Transfer in Micro Gas Turbines

Verstraete, Tom; Alsalihi, Z.; Braembussche, R. A. Van den

doi:10.1115/1.2720874

Cited by 53 publications

(31 citation statements)

References 13 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…For the baseline model (0.02 kg/s) the influx of thermal energy in the compressor represents 4% of the work input. When the mass flow is reduced to 0.008 kg/s, representing a reduction in rotor diameter from 20 mm to 12.6 mm, the thermal energy input rises to almost 7% of the compressor power which causes a drop in specific output power of 5% and in the thermal efficiency of 5.9%, which is consistent with results obtained using a conjugate heat transfer analysis [39]. Figs.…”

Section: Impact Of Micro Turbine Sizesupporting

confidence: 86%

“…2 shows that the heat rate conducted through the shaft represents only 4% of the total power output, despite the relatively short shaft. This confirms that at high rotational speeds the effects of heat transfer on compressor performance are relatively small [24,39,40]. The compressor heating through the housing is of the same magnitude which is partially due to the high heat losses of the combustion chamber (302 W) and partially due to the higher conductivity of stainless steel compared to Inconel.…”

Section: Baseline Configurationsupporting

confidence: 78%

See 1 more Smart Citation

Impact of heat transfer on the performance of micro gas turbines

Verstraete

Bowkett

2015

Applied Energy

View full text Add to dashboard Cite

Section: Impact Of Micro Turbine Sizesupporting

confidence: 86%

Section: Baseline Configurationsupporting

confidence: 78%

Impact of heat transfer on the performance of micro gas turbines

Verstraete

Bowkett

2015

Applied Energy

View full text Add to dashboard Cite

“…The major issue is how to evaluate the heat transfer coefficients h. A simpler approach pursued in [3,15,16] is to select a constant positive value of h. In that case the scheme may be viewed as a form of under-relaxation of each iteration that increases the stability yet does not improve the linear convergence rate of the fixed-point iteration process.…”

Section: Convective Formulation Of Heat Fluxmentioning

confidence: 99%

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

Ganine

Javiya

Hills

et al. 2012

Journal of Engineering for Gas Turbines and Power

View full text Add to dashboard Cite

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-...

show abstract

“…Instead of providing a pure heat flux, q w boundary condition on the solid FE domains, a heat transfer coefficient h, and fluid temperature T f were used such that q w =h(T f -T w ). This results in a better convergence rate for the coupled iterative calculations (Verdicchio [4], Verstraete et al [13]). Values of h at each boundary node were calculated from two different CFD solutions for heat flux q w and q w,2 ,with different wall temperatures T w and T w +∆T w using the following equation.…”

Section: Coupled Fe-cfd Methodologymentioning

confidence: 99%

Coupled FE–CFD thermal analysis for a cooled turbine disk

Javiya

Chew

Hills

et al. 2015

Proceedings of the Institution of Mechanical Engineers, Part C:

View full text Add to dashboard Cite

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.

show abstract

Numerical Study of the Heat Transfer in Micro Gas Turbines

Cited by 53 publications

References 13 publications

Impact of heat transfer on the performance of micro gas turbines

Impact of heat transfer on the performance of micro gas turbines

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

Coupled FE–CFD thermal analysis for a cooled turbine disk

Contact Info

Product

Resources

About