Main Annulus Gas Path Interactions—Turbine Stator Well Heat Transfer

2013 ◽  
Vol 136 (2) ◽  
Author(s):  
Jeffrey A. Dixon ◽  
Antonio Guijarro Valencia ◽  
Daniel Coren ◽  
Daniel Eastwood ◽  
Christopher Long
Keyword(s):  
Heat Transfer ◽  
Gas Turbine ◽  
Effective Means ◽  
Engine Performance ◽  
Flow Distribution ◽  
Coupled Analysis ◽  
Test Rig ◽  
Cooling Flow ◽  
Turbine Stator ◽  
Optimization Study

This paper summarizes the work of a five year research program into the heat transfer within cavities adjacent to the main annulus of a gas turbine. The work has been a collaboration between several gas turbine manufacturers, also involving a number of universities working together. The principal objective of the study has been to develop and validate computer modeling methods of the cooling flow distribution and heat transfer management, in the environs of multistage turbine disk rims and blade fixings, with a view to maintaining component and subsystem integrity, while achieving optimum engine performance and minimizing emissions. A fully coupled analysis capability has been developed using combinations of commercially available and in-house computational fluid dynamics (CFD) and finite element (FE) thermomechanical modeling codes. The main objective of the methodology is to help decide on optimum cooling configurations for disk temperature, stress, and life considerations. The new capability also gives us an effective means of validating the method by direct use of disk temperature measurements, where otherwise, additional and difficult to obtain parameters, such as reliable heat flux measurements, would be considered necessary for validation of the use of CFD for convective heat transfer. A two-stage turbine test rig has been developed and improved to provide good quality thermal boundary condition data with which to validate the analysis methods. A cooling flow optimization study has also been performed to support a redesign of the turbine stator well cavity to maximize the effectiveness of cooling air supplied to the disk rim region. The benefits of this design change have also been demonstrated on the rig. A brief description of the test rig facility will be provided together with some insights into the successful completion of the test program. Comparisons will be provided of disk rim cooling performance for a range of cooling flows and geometry configurations. The new elements of this work are the presentation of additional test data and validation of the automatically coupled analysis method applied to a partially cooled stator well cavity (i.e., including some local gas ingestion) and also the extension of the cavity cooling design optimization study to other new geometries.

Main Annulus Gas Path Interactions: Turbine Stator Well Heat Transfer

2012 ◽  
Author(s):  
Jeffrey A. Dixon ◽  
Antonio Guijarro Valencia ◽  
Daniel Coren ◽  
Daniel Eastwood ◽  
Christopher Long
Keyword(s):  
Heat Transfer ◽  
Gas Turbine ◽  
Computer Modelling ◽  
Effective Means ◽  
Research Programme ◽  
Coupled Analysis ◽  
Test Rig ◽  
Cooling Flow ◽  
Turbine Stator ◽  
System Integrity

This paper summarises the work of a 5-year research programme into the heat transfer within cavities adjacent to the main annulus of a gas turbine. The work has been a collaboration between several gas turbine manufacturers, also involving a number of universities working together. The principal objective of the study has been to develop and validate computer modelling methods of the cooling flow distribution and heat transfer management, in the environs of multi-stage turbine disc rims and blade fixings, with a view to maintaining component and sub-system integrity, whilst achieving optimum engine performance and minimising emissions. A fully coupled analysis capability has been developed using combinations of commercially available and in-house computational fluid dynamics (CFD) and finite element (FE) thermo-mechanical modelling codes. The main objective of the methodology is to help decide on optimum cooling configurations for disc temperature, stress and life considerations. The new capability also gives us an effective means of validating the method by direct use of disc temperature measurements, where otherwise, additional and difficult to obtain parameters, such as reliable heat flux measurements, would be considered necessary for validation of the use of CFD for convective heat transfer. A two-stage turbine test rig has been developed and improved to provide good quality thermal boundary condition data with which to validate the analysis methods. A cooling flow optimisation study has also been performed to support a re-design of the turbine stator well cavity, to maximise the effectiveness of cooling air supplied to the disc rim region. The benefits of this design change have also been demonstrated on the rig. A brief description of the test rig facility will be provided together with some insights into the successful completion of the test programme. Comparisons will be provided of disc rim cooling performance, for a range of cooling flows and geometry configurations. The new elements of this work are the presentation of additional test data and validation of the automatically coupled analysis method applied to a partially cooled stator well cavity, (i.e. including some local gas ingestion); also the extension of the cavity cooling design optimisation study to other new geometries.

Heat Transfer in Turbine Hub Cavities Adjacent to the Main Gas Path Including FE-CFD Coupled Thermal Analysis

2011 ◽  
Author(s):  
Antonio Guijarro Valencia ◽  
Jeffrey A. Dixon ◽  
Attilio Guardini ◽  
Daniel D. Coren ◽  
Daniel Eastwood
Keyword(s):  
Heat Transfer ◽  
Gas Turbines ◽  
Flow Distribution ◽  
Research Programme ◽  
Coupled Analysis ◽  
Analysis Method ◽  
Fe Modelling ◽  
Turbine Stator ◽  
Fuel Burn ◽  
Air Supply

Reliable means of predicting heat transfer in cavities adjacent to the main gas path are increasingly being sought by engineers involved in the design of gas turbines. In this paper an up-dated analysis of the interim results from an extended research programme, MAGPI, sponsored by the EU and several leading gas turbine manufactures and universities, will be presented. Extensive use is made of CFD and FE modelling techniques to understand the thermo-mechanical behaviour and convective heat transfer of a turbine stator well cavity, including the interaction of cooling air supply with the main annulus gas. It is also important to establish the hot running seal clearances for a full understanding of the cooling flow distribution and heat transfer in the cavity. The objective of the study has been to provide a means of optimising the design of such cavities (see Figure 1) for maintaining a safe environment for critical parts, such as disc rims and blade fixings, whilst maximising the turbine efficiency by means of reducing the fuel burn and emissions penalties associated with the secondary airflow system. The modelling methods employed have been validated against data gathered from a dedicated two-stage turbine rig, running at engine representative conditions. Extensive measurements are available for a range of flow conditions and alternative cooling arrangements. The analysis method has been used to inform a design change which will be tested in a second test phase. Data from this test will also be used to further benchmark the analysis method. Comparisons are provided between the predictions and measurements from the original configuration, turbine stator well component temperature survey, including the use of a coupled analysis technique between FE and CFD solutions.

Turbine Stator Well Heat Transfer and Cooling Flow Optimisation

2006 ◽  
Author(s):  
Jeffrey A. Dixon ◽  
Ivan L. Brunton ◽  
Timothy J. Scanlon ◽  
Grzegorz Wojciechowski ◽  
Vassilis Stefanis ◽  
...  
Keyword(s):  
Heat Transfer ◽  
System Analysis ◽  
Flow Distribution ◽  
Test Facility ◽  
Analysis And Design ◽  
Cooling Flow ◽  
Turbine Stator ◽  
Temperature Levels ◽  
Area Of Concern ◽  
Cooling Air

CFD methods are increasingly being used in gas turbine secondary flow system analysis and design to establish flow distribution and convective heat transfer in internal cavities. A key area of concern is the complex flows adjacent to turbine disc rims, where undesirable levels of hot annulus gas would be ingested were it not for the cooling air supplied to limit its effects on disc rim and blade fixing temperature levels. This paper presents results from a study to investigate the practicality of applying this method to the flow distribution and heat transfer in the disc rim sealing cavity between two adjacent turbine stages, referred to here as a turbine stator well. Also described is the test facility designed to validate the CFD analysis and some preliminary results from comparisons of 3D flow solutions, with measured test data.

Comparison of 3D Unsteady Transient Conjugate Heat Transfer Analysis on a High Pressure Cooled Turbine Stage With Experimental Data

2017 ◽  
Author(s):  
Jong-Shang Liu ◽  
Mark C. Morris ◽  
Malak F. Malak ◽  
Randall M. Mathison ◽  
Michael G. Dunn
Keyword(s):  
Heat Transfer ◽  
Experimental Data ◽  
Heat Flux ◽  
High Pressure ◽  
High Temperature ◽  
Gas Turbine ◽  
Conjugate Heat Transfer ◽  
Turbine Rotor ◽  
Turbine Stage ◽  
Cooling Flow

In order to have higher power to weight ratio and higher efficiency gas turbine engines, turbine inlet temperatures continue to rise. State-of-the-art turbine inlet temperatures now exceed the turbine rotor material capability. Accordingly, one of the best methods to protect turbine airfoil surfaces is to use film cooling on the airfoil external surfaces. In general, sizable amounts of expensive cooling flow delivered from the core compressor are used to cool the high temperature surfaces. That sizable cooling flow, on the order of 20% of the compressor core flow, adversely impacts the overall engine performance and hence the engine power density. With better understanding of the cooling flow and accurate prediction of the heat transfer distribution on airfoil surfaces, heat transfer designers can have a more efficient design to reduce the cooling flow needed for high temperature components and improve turbine efficiency. This in turn lowers the overall specific fuel consumption (SFC) for the engine. Accurate prediction of rotor metal temperature is also critical for calculations of cyclic thermal stress, oxidation, and component life. The utilization of three-dimensional computational fluid dynamics (3D CFD) codes for turbomachinery aerodynamic design and analysis is now a routine practice in the gas turbine industry. The accurate heat-transfer and metal-temperature prediction capability of any CFD code, however, remains challenging. This difficulty is primarily due to the complex flow environment of the high-pressure turbine, which features high speed rotating flow, coupling of internal and external unsteady flows, and film-cooled, heat transfer enhancement schemes. In this study, conjugate heat transfer (CHT) simulations are performed on a high-pressure cooled turbine stage, and the heat flux results at mid span are compared to experimental data obtained at The Ohio State University Gas Turbine Laboratory (OSUGTL). Due to the large difference in time scales between fluid and solid, the fluid domain is simulated as steady state while the solid domain is simulated as transient in CHT simulation. This paper compares the unsteady and transient results of the heat flux on a high-pressure cooled turbine rotor with measurements obtained at OSUGTL.

Heat Transfer Measurements of Oblong Pins

2014 ◽  
Author(s):  
Kathryn L. Kirsch ◽  
Karen A. Thole
Keyword(s):  
Heat Transfer ◽  
Gas Turbine ◽  
Flow Direction ◽  
Effective Means ◽  
Transfer Enhancement ◽  
Pin Fin ◽  
The Third ◽  
Pin Fins ◽  
Two Peaks ◽  
Pin Fin Arrays

Pin fin arrays are employed as an effective means for heat transfer enhancement in the internal passages of a gas turbine blade, specifically in the blade’s trailing edge. Various shapes of the pin itself have been used in such arrays. In this study, oblong pin fins are investigated whereby their long axis is perpendicular to the flow direction. Heat transfer measurements were taken at the pin mid-span with unheated endwalls to isolate the pin heat transfer. Results show important differences in the heat transfer patterns between a pin in the first row and a pin in the third row. In the third row, wider spanwise spacing allows for two peaks in heat transfer over the pin surface. Additionally, closer streamwise spacing leads to consistently higher heat transfer for the same spanwise spacing. Due to the blunt orientation of the pins, the peak in heat transfer occurs off the stagnation point.

The Application of Convective Cooling Enhancement of Span-Wise Cooling Holes in a Typical First Stage Turbine Blade

1991 ◽  
Author(s):  
D. J. Stankiewicz ◽  
T. R. Kirkham
Keyword(s):  
Heat Transfer ◽  
Heat Transfer Enhancement ◽  
Gas Turbine ◽  
Turbine Blade ◽  
Reynolds Numbers ◽  
Transfer Enhancement ◽  
Test Rig ◽  
Heated Oil ◽  
Cooling Enhancement ◽  
Mach And Reynolds Numbers

A technique of heat transfer enhancement is investigated whereby the internal span-wise cooling passages of a typical first stage gas turbine blade are modified by the introduction of circumferential ribs. The technique is verified by the use of a test rig incorporating a heated internally ribbed tube operating at the same range of Mach and Reynolds numbers as the turbine blade as well as by a test rig incorporating actual production blades immersed in a heated oil bath.

A numerical approach to the heat transfer and thermal stress in a gas turbine stator blade made of HfB2

2019 ◽  
Vol 45 (18) ◽  
pp. 24060-24069 ◽  
Author(s):  
Sahar Nekahi ◽  
Kourosh Vaferi ◽  
Mohammad Vajdi ◽  
Farhad Sadegh Moghanlou ◽  
Mehdi Shahedi Asl ◽  
...  
Keyword(s):  
Heat Transfer ◽  
Thermal Stress ◽  
Gas Turbine ◽  
Numerical Approach ◽  
Turbine Stator ◽  
Stator Blade

Turbine Stator Well CFD Studies: Effect of Upstream Egress Ingestion

2007 ◽  
Author(s):  
C. Georgakis ◽  
C. Whitney ◽  
G. Woollatt ◽  
V. Stefanis ◽  
P. Childs
Keyword(s):  
Heat Transfer ◽  
New Product Development ◽  
Engine Performance ◽  
Detailed Knowledge ◽  
Internal Cooling ◽  
Turbine Stator ◽  
Flow And Heat Transfer ◽  
Coolant Injection ◽  
Mainstream Flow ◽  
Overall Performance

There is a constant demand in the turbomachinery industry to improve engine performance, meet stringent environmental and safety regulations, and reduce the time and cost of new product development. As improvements in component efficiencies become increasingly difficult to achieve and new material development has become more expensive over the years, more attention is focusing on other areas of gas turbine technology. Internal cooling air systems, in particular, have been subject to significant research, in order to reduce the effect of parasitic losses on the overall engine performance. Often, part of the compressor flow passes directly into turbine inter-stage cavities primarily for rotor disc cooling. The advantages such a concept offers are (a) better thermal effectiveness on the rotor disc by having lower wall temperature (b) preventing, to some degree, the ingestion of mainstream hot gases into the cavity. These enhancements have to be integrated into the turbine stage without, of course, sacrificing the overall performance. Detailed knowledge of the flow and heat transfer within these cavities is needed if such improvements are to be further pursued. The material presented in this paper investigates the effect of upstream coolant injection into the mainstream flow being ingested into a turbine stator well. The coolant injection comes from an upstream rim seal, and so called egress. The CFD domain modelled includes both the main gas path and stator well. CFD studies have been performed to predict the flow physics in the cavity, and this has included an investigation of both steady and unsteady effects. This study is extended beyond the cavity flows, and it gives an insight of the mainstream flow particularly behind the blade rows. The CFD results are compared with dedicated aerodynamic 3D-blade design codes. These CFD studies have contributed significantly in understanding the effect on flow and heat transfer of upstream turbine coolant injection being subsequently ingested into a downstream stator well. Most importantly, these CFD studies enhanced the optimisation of turbine stator well design and limited the coolant flow ingested into the rotating cavities whilst maintaining overall performance.

scholarly journals Conjugate Heat Transfer of an Internally Air-Cooled Nozzle Guide Vane and Shrouds

2014 ◽  
Vol 6 ◽  
pp. 146523 ◽  
Author(s):  
Leiyong Jiang ◽  
Xijia Wu ◽  
Zhong Zhang
Keyword(s):  
Heat Transfer ◽  
Gas Turbine ◽  
Conjugate Heat Transfer ◽  
Guide Vane ◽  
Operating Conditions ◽  
Temperature Fields ◽  
Pressure Side ◽  
Cooling Flow ◽  
Nozzle Guide Vane ◽  
Nozzle Guide

In order to assess the life of gas turbine critical components, it is essential to adequately specify their aerothermodynamic working environments. Steady-state analyses of the flow field and conjugate heat transfer of an internally air-cooled nozzle guide vane (NGV) and shrouds of a gas turbine engine at baseline operating conditions are numerically investigated. A high-fidelity CFD model is generated and the simulations are carried out with properly defined boundary conditions. The features of the complicated flow and temperature fields are revealed. In general, the Mach number is lower and the temperature is higher on the NGV pressure side than those on the suction side. There are two high temperature regions on the pressure side, and the temperature across the middle section is relatively low. These findings are closely related to the locations of the holes and outlets of the cooling flow passage, and consistent with the field observations of damaged NGVs. As a technology demonstration, the results provide required information for the life analysis of the NGV/shrouds assembly and improvement of the cooling flow arrangement.

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