Heat Transfer in Turbine Hub Cavities Adjacent to the Main Gas Path

2010 ◽  
Author(s):  
Jeffrey A. Dixon ◽  
Antonio Guijarro ◽  
Andreas Bauknecht ◽  
Daniel Coren ◽  
Nick Atkins
Keyword(s):  
Heat Transfer ◽  
Gas Turbines ◽  
Research Programme ◽  
Fe Modelling ◽  
Turbine Stator ◽  
Turbine Efficiency ◽  
Fuel Burn ◽  
Air Supply ◽  
Modelling Techniques ◽  
Cooling Air

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 interim summary of the results of a four-year research programme 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 of a turbine stator well cavity, including the interaction of cooling air supply with the main annulus gas (see Figure 1). The objective of the study has been to provide a means of optimising the design of such cavities for maintaining a safe environment for critical parts, such as disc rims and blade fixings, whilst maximising the turbine efficiency, and minimising 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 is also to be tested. Comparisons are provided between the predictions and measurements of the turbine stator well component temperature.

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.

Heat Transfer in Turbine Hub Cavities Adjacent to the Main Gas Path

2012 ◽  
Vol 135 (2) ◽  
Author(s):  
Jeffrey A. Dixon ◽  
Antonio Guijarro Valencia ◽  
Andreas Bauknecht ◽  
Daniel Coren ◽  
Nick Atkins
Keyword(s):  
Heat Transfer ◽  
Gas Turbines ◽  
The European Union ◽  
Turbine Stator ◽  
Turbine Efficiency ◽  
Fuel Burn ◽  
Air Supply ◽  
Computational Fluid Dynamics Cfd ◽  
Cooling Air ◽  
Component Temperature

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 interim summary of the results of a five-year research program sponsored by the European Union (EU) and several leading gas turbine manufacturers and universities will be presented. Extensive use is made of computational fluid dynamics (CFD) and finite element (FE) modeling techniques to understand the thermo-mechanical behavior of a turbine stator well cavity, including the interaction of cooling air supply with the main annulus gas. The objective of the study has been to provide a means of optimizing the design of such cavities for maintaining a safe environment for critical parts, such as disc rims and blade fixings, while maximizing the turbine efficiency and minimizing the fuel burn and emissions penalties associated with the secondary airflow system. The modeling 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 is also to be tested. Comparisons are provided between the predictions and measurements of the turbine stator well component temperature.

An Investigation Into Numerical Analysis Alternatives for Predicting Re-Ingestion in Turbine Disc Rim Cavities

2012 ◽  
Author(s):  
Antonio Guijarro Valencia ◽  
Jeffrey A. Dixon ◽  
Riccardo Da Soghe ◽  
Bruno Facchini ◽  
Peter E. J. Smith ◽  
...  
Keyword(s):  
Gas Turbines ◽  
Turbulence Models ◽  
Research Programme ◽  
Paper Analysis ◽  
Main Stream ◽  
Cfd Modelling ◽  
Cooling Flow ◽  
Air Supply ◽  
Modelling Techniques ◽  
Cooling Air

Reliable means of predicting ingestion in cavities adjacent to the main gas path are increasingly being sought by engineers involved in the design of gas turbines. In this paper, analysis is to be presented that results from an extended research programme, MAGPI, sponsored by the EU and several leading gas turbine manufactures and universities. Extensive use is made of CFD modelling techniques to understand the aerodynamic behaviour of a turbine stator well cavity, focusing on the interaction of cooling air supply with the main annulus gas. The objective of the study has been to benchmark a number of CFD codes and numerical techniques covering RANS and URANS calculations with different turbulence models in order to assess the suitability of the standard settings used in the industry for calculating the mechanics of the flow travelling between cavities in a turbine through the main gas path. The modelling methods employed have been compared making use of experimental 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 limitations of the numerical methods in calculating the interaction of the cooling flow egress and the main stream gas, and subsequent ingestion into downstream cavities in the engine (i.e. re-ingestion), have been exposed. This has been done without losing sight of the validation of the CFD for its use for predicting heat transfer, which was the main objective of the partners of the MAGPI Work-Package 1 consortium.

Turbine Stator Well CFD Studies: Effects of Cavity Cooling Air Flow

2008 ◽  
Author(s):  
Antonio Andreini ◽  
Riccardo Da Soghe ◽  
Bruno Facchini ◽  
Stefano Zecchi
Keyword(s):  
Heat Transfer ◽  
Gas Turbines ◽  
Numerical Models ◽  
Engine Performance ◽  
Research Programme ◽  
Experimental Tests ◽  
Air Cooling ◽  
Manufacturing Companies ◽  
Secondary Air ◽  
Cooling Air

The improvement of the aerodynamic efficiency of gas turbine components is becoming more and more difficult to achieve. Nevertheless there are still some devices that could be improved to enhance engine performance. Further investigations on the internal air cooling systems, for instance, may lead to a reduction of cavities cooling air with a direct beneficial effect on engine performance. At the same time, further investigations on heat transfer mechanisms within turbine cavities may help to optimize cooling air flows saving engine life duration. This paper presents some CFD preliminary studies conducted on an two-stage axial turbine rig developed in a research programme on internal air systems funded by EU, named the Main Annulus Gas Path Interactions (MAGPI). Each turbine stage consists of 39 vanes and 78 rotating blades and the modelled domain includes both the main gas path of the two turbine stages and the second stator well. Pre experimental tests CFD computations were planned in order to point out the reliability of numerical models in the description of the flow patterns in the main annulus and in the cavities. Several computational meshes were considered with steady and unsteady approaches in order to assess the sensitivity to computational approach regarding the evaluation of the interactions between main annulus and disk cavities flows. Results were obtained for several cavities cooling air mass-flow rates and data were further analyzed to investigate the influence of the sealing flow inside the main annulus. MAGPI project is a 4 years Specific-Targeted-Research-Project (2007–2011) and its consortium includes six universities and nine gas turbines manufacturing companies. The project is focused on the analysis of interactions between primary and secondary air systems achieving a novel approach as these systems have, up to now, only been considered separately. In particular one of the tasks of the project will focus on heat transfer phenomena and delivering experimental data which will be used to validate the advanced design tools used by industries (CFD codes and correlative formulations).

ICAS-GT: A European Collaborative Research Programme on Internal Cooling Air Systems for Gas Turbines

2002 ◽  
Author(s):  
Peter D. Smout ◽  
John W. Chew ◽  
Peter R. N. Childs
Keyword(s):  
Heat Transfer ◽  
Gas Turbines ◽  
Research Programme ◽  
Cavity Flow ◽  
Internal Cooling ◽  
Manufacturing Companies ◽  
Flow And Heat Transfer ◽  
Rotating Cavity ◽  
Internal Fluid Flow ◽  
Cooling Air

The Internal Cooling Air Systems for Gas Turbines (ICAS-GT) research programme, sponsored by the European Commission, ran from January 1998 to December 2000, and was undertaken by a consortium of ten gas turbine manufacturing companies and four universities. Research was concentrated in five discrete but related areas of the air system including turbine rim seals, rotating cavity flow and heat transfer, and turbine pre-swirl system effectiveness. In each case, experiments were conducted to extend the database of pressure, temperature, flow and heat transfer measurements to engine representative non-dimensional conditions. The data was used to develop correlations, and to validate CFD and FE calculation methods, for internal fluid flow and heat transfer. This paper summarises the outcome of the project by presenting a sample of experimental results from each technical work package. Examples of the associated CFD calculations are included to illustrate the progress made in developing validated tools for predicting rotating cavity flow and heat transfer over an engine representative range of flow conditions.

Structural Deflection’s Impact in Turbine Stator Well Heat Transfer

2016 ◽  
Author(s):  
Julien Pohl ◽  
Harvey Thompson ◽  
Antonio Guijarro Valencia ◽  
Gregorio López Juste ◽  
Vincenzo Fico ◽  
...  
Keyword(s):  
Heat Transfer ◽  
Test Data ◽  
Internal Flow ◽  
Research Programme ◽  
Turbine Stator ◽  
Air Temperatures ◽  
Air Supply ◽  
Flow Interactions ◽  
Commercial Solver ◽  
The Impact

In the most evolved designs, it is common practice to expose engine components to main annulus air temperatures exceeding the thermal material limit in order to increase the overall performance and to minimise the engine specific fuel consumption (SFC). To prevent overheating of the materials and thus the reduction of the component life, an internal flow system is required to cool the critical engine parts and to protect them. This paper shows a practical application and extension of the methodology developed during the five year research programme MAGPI. Extensive use was made of FEA (solids) and CFD (fluid) modelling techniques to understand the thermo-mechanical behaviour of a dedicated turbine stator well cavity rig, due to the interaction of cooling air supply with the main annulus. Previous work based on the same rig showed difficulties in matching predictions to thermocouple measurements near the rim seal gap. In this investigation, two different types of turbine stator well geometries were analysed, where further use was made of existing measurements of hot running seal clearances in the rig. The structural deflections were applied to the existing models to evaluate the impact in flow interactions and heat transfer. Additionally to the already evaluated test cases without net ingestion, cases simulating engine deterioration with net ingestion were validated against the available test data, also taking into account cold and hot running seal clearances. 3D CFD simulations were conducted using the commercial solver FLUENT coupled to the in-house FEA tool SC03 to validate against available test data of the dedicated rig.

Effect of pre-swirl nozzle closure modes on unsteady flow and heat transfer characteristics in a pre-swirl system of aero-engine

2021 ◽  
pp. 095441002110191
Author(s):  
Gaowen Liu ◽  
Zhao Lei ◽  
Aqiang Lin ◽  
Qing Feng ◽  
Yan Chen
Keyword(s):  
Heat Transfer ◽  
Mass Flow Rate ◽  
Mass Flow ◽  
Flow Rate ◽  
Temperature Drop ◽  
Thermodynamic Characteristics ◽  
Circumferential Direction ◽  
Temperature Changes ◽  
Air Supply ◽  
Cooling Air

The pre-swirl system is of great importance for temperature drop and cooling air supply. This study aims to investigate the influencing mechanism of heat transfer, nonuniform thermodynamic characteristics, and cooling air supply sensitivity in a pre-swirl system by the application of the flow control method of the pre-swirl nozzle. A novel test rig was proposed to actively control the supplied cooling air mass flow rate by three adjustable pre-swirl nozzles. Then, the transient problem of the pre-swirl system was numerically conducted by comparison with 60°, 120°, and 180° rotating disk cavity cases, which were verified with the experiment results. Results show that the partial nozzle closure will aggravate the fluctuation of air supply mass flow rate and temperature. When three parts of nozzles are closed evenly at 120° in the circumferential direction, the maximum value of the nonuniformity coefficient of air supply mass flow rate changes to 3.1% and that of temperature changes to 0.25%. When six parts of nozzles are closed evenly at 60° in the circumferential direction, the maximum nonuniformity coefficient of air supply mass flow rate changes to 1.4% and that of temperature changes to 0.20%. However, different partial nozzle closure modes have little effect on the average air supply parameters. Closing 14.3% of the nozzle area will reduce the air supply mass flow rate by 9.9% and the average air supply temperature by about 1 K.

Flow and Heat Transfer in a Preswirl Rotor–Stator System

1997 ◽  
Vol 119 (2) ◽  
pp. 364-373 ◽  
Author(s):  
M. Wilson ◽  
R. Pilbrow ◽  
J. M. Owen
Keyword(s):  
Heat Transfer ◽  
Gas Turbines ◽  
Heat Fluxes ◽  
Valuable Insight ◽  
Swirl Ratio ◽  
Blade Cooling ◽  
Nusselt Numbers ◽  
Air Temperatures ◽  
Via Holes ◽  
Cooling Air

Conditions in the internal-air system of a high-pressure turbine stage are modeled using a rig comprising an outer preswirl chamber separated by a seal from an inner rotor-stator system. Preswirl nozzles in the stator supply the “blade-cooling” air, which leaves the system via holes in the rotor, and disk-cooling air enters at the center of the system and leaves through clearances in the peripheral seals. The experimental rig is instrumented with thermocouples, fluxmeters, pitot tubes, and pressure taps, enabling temperatures, heat fluxes, velocities, and pressures to be measured at a number of radial locations. For rotational Reynolds numbers of Reφ ≃ 1.2 × 106, the swirl ratio and the ratios of disk-cooling and blade-cooling flow rates are chosen to be representative of those found inside gas turbines. Measured radial distributions of velocity, temperature, and Nusselt number are compared with computations obtained from an axisymmetric elliptic solver, featuring a low-Reynolds-number k–ε turbulence model. For the inner rotor-stator system, the computed core temperatures and velocities are in good agreement with measured values, but the Nusselt numbers are underpredicted. For the outer preswirl chamber, it was possible to make comparisons between the measured and computed values for cooling-air temperatures but not for the Nusselt numbers. As expected, the temperature of the blade-cooling air decreases as the inlet swirl ratio increases, but the computed air temperatures are significantly lower than the measured ones. Overall, the results give valuable insight into some of the heat transfer characteristics of this complex system.

scholarly journals Aerothermal Analysis of a Turbine Casing Impingement Cooling System

2012 ◽  
Vol 2012 ◽  
pp. 1-10 ◽  
Author(s):  
Riccardo Da Soghe ◽  
Bruno Facchini ◽  
Mirko Micio ◽  
Antonio Andreini
Keyword(s):  
Heat Transfer ◽  
Pressure Drop ◽  
Cooling System ◽  
Control Valve ◽  
Impinging Jets ◽  
Present System ◽  
Air Supply ◽  
Supply Pipe ◽  
Turbine Casing ◽  
Cooling Air

Heat transfer and pressure drop for a representative part of a turbine active cooling system were numerically investigated by means of an in-house code. This code has been developed in the framework of an internal research program and has been validated by experiments and CFD. The analysed system represents the classical open bird cage arrangement that consists of an air supply pipe with a control valve and the present system with a collector box and pipes, which distribute cooling air in circumferential direction of the casing. The cooling air leaves the ACC system through small holes at the bottom of the tubes. These tubes extend at about 180° around the casing and may involve a huge number of impinging holes; as a consequence, the impinging jets mass flow rate may vary considerably along the feeding manifold with a direct impact on the achievable heat transfer levels. This study focuses on the performance, in terms of heat transfer coefficient and pressure drop, of several impinging tube geometries. As a result of this analysis, several design solutions have been compared and discussed.

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.

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