Metal Temperature Prediction of a DLN1 Class Flame Tube by CFD CHT Approach

2015 ◽  
Author(s):  
Riccardo Da Soghe ◽  
Cosimo Bianchini ◽  
Antonio Andreini ◽  
Lorenzo Mazzei ◽  
Giovanni Riccio ◽  
...  
Keyword(s):  
Heat Transfer ◽  
Operating Conditions ◽  
Metal Temperature ◽  
Thermal Loads ◽  
Flame Tube ◽  
Numerical Predictions ◽  
Partial Load ◽  
Temperature Combustion ◽  
Critical Components ◽  
Tube Life

Combustor liner of present gas turbine engines is subjected to high thermal loads as it surrounds high temperature combustion reactants and is hence facing the related radiative load. This generally produces high thermal stress levels on the liner, strongly limiting its life expectations and making it one of the most critical components of the entire engine. The reliable prediction of such thermal loads is hence a crucial aspect to increase the flame tube life span and to ensure safe operations. The present study aims at investigating the aero-thermal behavior of a GE DLN1 (Dry Low NOx) class flame tube and in particular at evaluating working metal temperatures of the liner in relation to the flow and heat transfer state inside and outside the combustion chamber. Three different operating conditions have been accounted for (i.e. Lean-Lean partial load, Premixed full load and Primary load) to determine the amount of heat transfer from the gas to the liner by means of CFD. The numerical predictions have been compared to experimental measurements of metal temperature showing a good agreement between CFD and experiments.

Metal Temperature Prediction of a Dry Low NOx Class Flame Tube by Computational Fluid Dynamics Conjugate Heat Transfer Approach

2015 ◽  
Vol 138 (3) ◽  
Author(s):  
Riccardo Da Soghe ◽  
Cosimo Bianchini ◽  
Antonio Andreini ◽  
Lorenzo Mazzei ◽  
Giovanni Riccio ◽  
...  
Keyword(s):  
Heat Transfer ◽  
Fluid Dynamics ◽  
Computational Fluid Dynamics ◽  
Operating Conditions ◽  
Metal Temperature ◽  
Thermal Loads ◽  
Flame Tube ◽  
Numerical Predictions ◽  
Partial Load ◽  
Critical Components

Combustor liner of present gas turbine engines is subjected to high thermal loads as it surrounds high temperature combustion reactants and is hence facing the related radiative load. This generally produces high thermal stress levels on the liner, strongly limiting its life expectations and making it one of the most critical components of the entire engine. The reliable prediction of such thermal loads is hence a crucial aspect to increase the flame tube life span and to ensure safe operations. The present study aims at investigating the aerothermal behavior of a GE Dry Low NOx (DLN1) class flame tube and in particular at evaluating working metal temperatures of the liner in relation to the flow and heat transfer state inside and outside the combustion chamber. Three different operating conditions have been accounted for (i.e., lean–lean partial load, premixed full load, and primary load) to determine the amount of heat transfer from the gas to the liner by means of computational fluid dynamics (CFD). The numerical predictions have been compared to experimental measurements of metal temperature showing a good agreement between CFD and experiments.

A Novel Transition-Sensitive Conjugate Methodology Applied to Turbine Vane Heat Transfer

2003 ◽  
Author(s):  
William D. York ◽  
D. Keith Walters ◽  
James H. Leylek
Keyword(s):  
Heat Transfer ◽  
Boundary Layer ◽  
Turbulent Boundary Layer ◽  
Conjugate Heat Transfer ◽  
Operating Conditions ◽  
Boundary Layer Transition ◽  
Airfoil Surface ◽  
New Model ◽  
Numerical Predictions ◽  
Turbine Vane

A documented numerical methodology for conjugate heat transfer was employed to predict the metal temperature of an internally-cooled gas turbine vane at realistic operating conditions. The conjugate heat transfer approach involves the simultaneous solution of the flow field (convection) and the conduction within the metal vane, allowing a solution of the complete heat transfer problem in a single simulation. This technique means better accuracy and faster turn-around time than the typical industry practice of multiple, decoupled solutions. In the present simulations, the solid and fluid zones were coupled by energy conservation at the interfaces. In the fluid zones, the Reynoldsaveraged Navier-Stokes equations were closed with a three-equation, eddy-viscosity model, developed in-house and previously documented, with the capability to predict laminar-to-turbulent boundary-layer transition. The single-point model is fully-predictive for transition and requires no problem-dependent user inputs. For comparison, a simulation was also run with a commercially available Realizable k-ε turbulence model. A high-quality, unstructured gird was employed in both cases. Numerical predictions for midspan temperature on the airfoil surface are compared to data from an open-literature experiment with the same geometry and operating conditions. The new model captured transition of the initially laminar boundary layer to a turbulent boundary layer on the suction surface. The results with the new model show excellent agreement with measured data for surface temperature over the majority of the airfoil surface. The new model showed a marked improvement over the Realizable k-ε model in all regions where laminar boundary layers exist, highlighting the importance of accurately modeling transition in turbomachinery heat transfer simulations.

Thermo Fluid Dynamic Analysis of a Gas Turbine Transition-Piece

2014 ◽  
Author(s):  
Riccardo Da Soghe ◽  
Cosimo Bianchini ◽  
Antonio Andreini ◽  
Lorenzo Mazzei ◽  
Giovanni Riccio ◽  
...  
Keyword(s):  
Heat Transfer ◽  
Heat Transfer Coefficient ◽  
Transfer Coefficient ◽  
Gas Turbine ◽  
Fluid Dynamic ◽  
Gas Turbine Engine ◽  
Operating Conditions ◽  
Thermal Loads ◽  
Turbine Engine ◽  
Transition Piece

The transition-piece of a gas turbine engine is subjected to high thermal loads as it collects high temperature combustion products from the gas generator to a turbine. This generally produces high thermal stress levels in the casing of the transition piece, strongly limiting its life expectations and making it one of the most critical components of the entire engine. The reliable prediction of such thermal loads is hence a crucial aspect to increase the transition-piece life span and to assure safe operations. The present study aims to investigate the aero-thermal behaviour of a gas turbine engine transition-piece and in particular to evaluate working temperatures of the casing in relation to the flow and heat transfer situation inside and outside the transition-piece. Typical operating conditions are considered to determine the amount of heat transfer from the gas to the casing by means of CFD. Both conjugate approach and wall fixed temperature have been considered to compute the heat transfer coefficient, and more in general, the transition-piece thermal loads. Finally a discussion on the most convenient heat transfer coefficient expression is provided.

The Effect of External Casing Impingement Cooling Manifold Standoff Distance on Casing Contraction for Thermal Control of Blade Tip Clearance

2017 ◽  
Author(s):  
Myeonggeun Choi ◽  
David R. H. Gillespie ◽  
Leo V. Lewis
Keyword(s):  
Heat Transfer ◽  
Heat Transfer Coefficient ◽  
Transfer Coefficient ◽  
Thermal Control ◽  
Operating Conditions ◽  
Standoff Distance ◽  
Impingement Cooling ◽  
Assembly Tolerance ◽  
Numerical Predictions ◽  
Blade Tip

Thermal closure of the engine casing is widely used to minimize undesirable blade tip leakage flows thus improving jet engine performance. This may be achieved using an impingement cooling scheme on the external casing wall, provided by manifolds attached to the outside of the engine. The assembly tolerance of these components leads to variation in the standoff distance between the manifold and the casing and its effects on casing contraction must be understood to allow build tolerance to be specified. For cooling arrangements with promising performance, the variation in closure with standoff distance of z/d = 1–6 were investigated. A cooling manifold, typical of that adopted by several engine companies, incorporating three different arrays of short cooling holes (chosen from previous study by Choi et al. (2016)) and thermal control dummy flanges were considered. A series of heat transfer tests using a transient liquid crystal technique were undertaken to measure spatially resolved heat transfer coefficient of a baseline sparse jet array. The experimental heat transfer results validated the extensive numerical predictions using RANS realizable k-epsilon turbulence model. The associated casing contraction was inferred from a finite element analysis using these distributions as the external casing thermal boundary condition. The flow in the system can be modulated to match the closure at different engine operating conditions, the relationship between thermal closure and coolant mass flow rates, inferred from the averaged jet Reynolds numbers assuming uniform distribution between cooling holes was predicted. Typical contractions of 0.5–2.2mm are achieved from the 0.02–0.35kg/s of the current casing cooling flows. The variation in heat transfer coefficient observed with standoff distance is much lower for the sparse array investigated compared to a previous designs employing arrays typical of blade cooling configurations. The reason for this is explained through interrogation of the local flow field and resultant heat transfer coefficient. This implies acceptable control of the circumferential uniformity of case cooling can be achieved with relatively large assembly tolerance of the manifold relative to the casing.

Procedure for Calculation of Component Thermal Loads for Running Clearances of Heavy-Duty Gas Turbines

2012 ◽  
Author(s):  
Luca Bozzi ◽  
Andrea Perrone ◽  
Luca Giacobone
Keyword(s):  
Heat Transfer ◽  
Gas Turbines ◽  
Fem Analysis ◽  
Operating Conditions ◽  
Computational Method ◽  
Heat Transfer Analysis ◽  
Thermal Loads ◽  
Transient Conditions ◽  
Analysis And Evaluation ◽  
Turbine Casing

The energy market development in the last decade has been influenced by several driving factors. To meet the strict customers’ requirements (related to low emissions, flexibility and high performances), operate gas turbine plants safely over a variety of off-design operating conditions has been fundamental. Accordingly, accurate evaluation of running clearances in stationary and transient conditions plays a significant role. On the other hand, the study of heat transfer in turbo-machinery is a fundamental activity to study the implications of off-design operating on components’ lifing. Focus of the paper is the analysis of variations of components’ wall temperature and clearances due to the fluctuation of thermal loads acting on gas turbines components during operation. The study is divided into two main sections: heat transfer analysis allows evaluating thermal loads and then a FEM analysis is performed in order to calculate the radial and axial clearances between rotor components and casing. Thermal loads are obtained by a computational method based on heat transfer correlations. Parametric curves have been developed to calculate variations of thermal loads in transient conditions from steady-state data obtained by the correlative computational tool. The two procedures for heat transfer analysis and evaluation of clearances have been validated against experimental data in several operating conditions. In particular, relative and absolute movements of rotor and turbine casing have been measured by means of proxy-meter probes located into the turbine bearing casing.

Conjugate Heat Transfer Analysis of a Cooled Turbine Vane Using the V2F Turbulence Model

2006 ◽  
Vol 129 (4) ◽  
pp. 773-781 ◽  
Author(s):  
Jiang Luo ◽  
Eli H. Razinsky
Keyword(s):  
Heat Transfer ◽  
Turbulence Model ◽  
Conjugate Heat Transfer ◽  
Solid Metal ◽  
Operating Conditions ◽  
Metal Temperature ◽  
Heat Transfer Analysis ◽  
Turbulent Heat Transfer ◽  
Internal Cooling ◽  
Turbine Vane

The conjugate heat transfer methodology has been employed to predict the flow and thermal properties including the metal temperature of a NASA turbine vane at three operating conditions. The turbine vane was cooled internally by air flowing through ten round pipes. The conjugate heat transfer methodology allows a simultaneous solution of aerodynamics and heat transfer in the external hot gas and the internal cooling passages and conduction within the solid metal, eliminating the need for multiple/decoupled solutions in a typical industry design process. The model of about 3 million computational meshes includes the gas path and the internal cooling channels, comprising hexa cells, and the solid metal comprising hexa and prism cells. The predicted aerodynamic loadings were found to be in close agreement with the data for all the cases. The predicted metal temperature, external, and internal heat transfer distributions at the midspan compared well with the measurement. The differences in the heat transfer rates and metal temperature under different running conditions were also captured well. The V2F turbulence model has been compared with a low-Reynolds-number k-ε model and a nonlinear quadratic k-ε model. The V2F model is found to provide the closest agreement with the data, though it still has room for improvement in predicting the boundary layer transition and turbulent heat transfer, especially on the suction side. The overall results are quite encouraging and indicate that conjugate heat transfer simulation with proper turbulence closure has the potential to become a viable tool in turbine heat transfer analysis and cooling design.

The Heat Transfer Characteristics of a 16 kW Steam Driven Double Effect Absorption Chiller

2008 ◽  
Author(s):  
Hongxi Yin ◽  
David H. Archer ◽  
Ming Qu
Keyword(s):  
Heat Transfer ◽  
Double Effect ◽  
Operating Conditions ◽  
Saturated Steam ◽  
Absorption Chiller ◽  
Transfer Coefficients ◽  
Heat Transfer Coefficients ◽  
Computational Performance ◽  
Partial Load ◽  
Wide Range

A 16 kW (4.6 refrigerant tons) steam driven, double effect, parallel flow absorption chiller has been designed, manufactured, and installed in the Intelligent Workplace (IW) of Carnegie Mellon University (CMU). This chiller is driven by 6 bar saturated steam and uses a 57% LiBr-H2O sorbent. It is the smallest absorption chiller available in the existing market. The absorption chiller consists of five major and four minor heat transfer components. The manufacturer of the chiller has provided information on detailed configuration and dimensions of these components to support the calculation of their heat transfer areas, A’s, and the estimation of overall heat transfer coefficients, U’s. A steady state computational performance model for the chiller has been developed based on the applicable scientific and engineering principles. The model has been used to calculate all chiller internal working conditions and to analyze the experimental data over a wide range of operating conditions. Heat transfer coefficients inside and outside of the tubes making up the chiller’s heat transfer components have been estimated by published empirical correlations. The product of the overall heat transfer coefficient and the surface contact area, UA’s, for the 5 major heat transfer components have been estimated using the chiller model and measured performance data. Significant variations, 30%, in this parameter are observed under partial load, reduced flow conditions. Deviations between the experimental measurements and the model solutions have been analyzed to evaluate the model accuracy. At design operating conditions, the overall deviation is about 6%.

Thermofluid Dynamic Analysis of a Gas Turbine Transition-Piece

2015 ◽  
Vol 137 (6) ◽  
Author(s):  
Riccardo Da Soghe ◽  
Cosimo Bianchini ◽  
Antonio Andreini ◽  
Lorenzo Mazzei ◽  
Giovanni Riccio ◽  
...  
Keyword(s):  
Heat Transfer ◽  
Gas Turbine ◽  
Combustion Products ◽  
Gas Turbine Engine ◽  
Operating Conditions ◽  
Thermal Loads ◽  
Gas Generator ◽  
Fixed Temperature ◽  
Turbine Engine ◽  
Transition Piece

The transition-piece of a gas turbine engine is subjected to high thermal loads as it collects high temperature combustion products from the gas generator to a turbine. This generally produces high thermal stress levels in the casing of the transition piece, strongly limiting its life expectations and making it one of the most critical components of the entire engine. The reliable prediction of such thermal loads is hence a crucial aspect to increase the transition-piece life span and to assure safe operations. The present study aims to investigate the aerothermal behavior of a gas turbine engine transition-piece and in particular to evaluate working temperatures of the casing in relation to the flow and heat transfer situation inside and outside the transition-piece. Typical operating conditions are considered to determine the amount of heat transfer from the gas to the casing by means of computational fluid dynamics (CFD). Both conjugate approach and wall fixed temperature have been considered to compute the heat transfer coefficient (HTC), and more in general, the transition-piece thermal loads. Finally a discussion on the most convenient HTC expression is provided.

Conjugate Heat Transfer Analysis of a Cooled Turbine Vane Using the V2F Turbulence Model

2006 ◽  
Author(s):  
Jiang Luo ◽  
Eli H. Razinsky
Keyword(s):  
Heat Transfer ◽  
Turbulence Model ◽  
Conjugate Heat Transfer ◽  
Solid Metal ◽  
Operating Conditions ◽  
Metal Temperature ◽  
Heat Transfer Analysis ◽  
Turbulent Heat Transfer ◽  
Internal Cooling ◽  
Turbine Vane

The conjugate heat transfer methodology has been employed to predict the flow and thermal properties including the metal temperature of a NASA turbine vane at three operating conditions. The turbine vane was cooled internally by air flowing through 10 round pipes. The conjugate heat transfer methodology allows a simultaneous solution of aerodynamics and heat transfer in the external hot gas and the internal cooling passages and conduction within the solid metal, eliminating the need for multiple/decoupled solutions in a typical industry design process. The model of about three million computational meshes includes the gas path and the internal cooling channels, comprising hexa cells, and the solid metal comprising hexa and prism cells. The predicted aerodynamic loadings were found to be in close agreement with the data for all the cases. The predicted metal temperature, external and internal heat transfer distributions at the mid-span compared well with the measurement. The differences in the heat transfer rates and metal temperature under different running conditions were also captured well. The V2F turbulence model has been compared with a low-Reynolds-number k-ε model and a non-linear quadratic k-ε model. The V2F model is found to provide the closest agreement with the data, though it still has room for improvement in predicting the boundary layer transition and turbulent heat transfer, especially on the suction side. The overall results are quite encouraging and indicate that conjugate heat transfer simulation with proper turbulence closure has the potential to become a viable tool in turbine heat transfer analysis and cooling design.

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