scholarly journals Development and Aerothermal Investigation of Integrated Combustor Vane Concept

2015 ◽  
Vol 138 (1) ◽  
Author(s):  
Simon Jacobi ◽  
Budimir Rosic
Keyword(s):  
Heat Transfer ◽  
Film Cooling ◽  
Gas Turbines ◽  
High Speed ◽  
Leading Edge ◽  
Cfd Simulations ◽  
Pressure Loss Coefficient ◽  
Novel Concept ◽  
Nozzle Guide ◽  
Stage Efficiency

This paper presents the development and aerothermal investigation of the integrated combustor vane concept for power generation gas turbines with individual can combustors. In this novel concept, first introduced in 2010, the conventional nozzle guide vanes (NGVs) are removed and flow turning is achieved by vanes that extend the combustor walls. The concept was developed using the in-house computational fluid dyanamics (CFD) code TBLOCK. Aerothermal experiments were conducted using a modular high-speed linear cascade, designed to model the flow at the combustor–vane interface. The facility is comprised of two can combustor transition ducts and either four conventional vanes (CVs) or two integrated vanes (IVs). The experimental study validates the linear CFD simulations of the IV development. Annular full-stage CFD simulations, used to evaluate aerodynamics, heat transfer, and stage efficiency, confirm the trends of the linear numerical and experimental results, and thus demonstrate the concept's potential for real gas turbine applications. Results show a reduction of the total pressure loss coefficient at the exit of the stator vanes by more than 25% due to a reduction in profile and endwall loss. Combined with an improved rotor performance demonstrated by unsteady stage simulations, these aerodynamic benefits result in a gain in stage efficiency of above 1%. A distinct reduction in heat transfer coefficient (HTC) levels on vane surfaces, on the order of 25–50%, and endwalls is observed and attributed to an altered state of boundary layer (BL) thickness. The development of IV's endwall- and leading edge (LE)-cooling geometry shows a superior surface coverage of cooling effectiveness, and the cooling requirements for the first vane are expected to be halved. Moreover, by halving the number of vanes, simplifying the design and eliminating the need for vane LE film cooling, manufacturing and development costs can be significantly reduced.

scholarly journals Development and Aerothermal Investigation of Integrated Combustor Vane Concept

2015 ◽  
Author(s):  
Simon Jacobi ◽  
Budimir Rosic
Keyword(s):  
Film Cooling ◽  
Gas Turbines ◽  
High Speed ◽  
Cfd Simulations ◽  
Pressure Loss Coefficient ◽  
Development Costs ◽  
Superior Surface ◽  
Novel Concept ◽  
Nozzle Guide ◽  
Stage Efficiency

This paper presents the development and aerothermal investigation of the Integrated Combustor Vane concept for power generation gas turbines with individual can combustors. In this novel concept, first introduced in 2010 [1], the conventional Nozzle Guide Vanes (NGVs) are removed and flow turning is achieved by vanes that extend the combustor walls. The concept is developed using the inhouse CFD code TBLOCK. Aerothermal experiments are conducted using a modular high speed linear cascade, designed to model the flow at the combustor-vane interface. The facility comprises two can combustor transition ducts and either four Conventional Vanes (CVs) or two Integrated Vanes (IVs). The experimental study validates the linear CFD-simulations of the IV development. Annular full stage CFD-simulations, used to evaluate aerodynamics, heat transfer and stage efficiency, confirm the trends of the linear numerical and experimental results and thus demonstrate the concept’s potential for real gas turbine applications. Results show a reduction of the total pressure loss coefficient at the exit of the stator vanes by more than 25% due to a reduction in profile- and endwall-loss. Combined with an improved rotor performance these aerodynamic benefits result in a gain in stage efficiency of above 1%, illustrated by unsteady stage simulations. A distinct reduction in HTC levels on vane surfaces, in the order of 25%–50%, and endwalls is observed and attributed to an altered state of boundary layer thickness. The development of IV’s endwall- and LE-cooling geometry shows a superior surface coverage of cooling effectiveness, and the cooling requirements for the first vane are expected to be halved. Moreover, by halving the number of vanes, simplifying the design and eliminating the need for vane LE film cooling, manufacturing and development costs can be significantly reduced.

Thermal Investigation of Integrated Combustor Vane Concept Under Engine-Realistic Conditions

2016 ◽  
Author(s):  
Simon Jacobi ◽  
Budimir Rosic
Keyword(s):  
Heat Transfer ◽  
Heat Transfer Coefficient ◽  
Transfer Coefficient ◽  
Gas Turbines ◽  
High Speed ◽  
Secondary Flows ◽  
Experimental Measurements ◽  
Thermal Investigation ◽  
Nozzle Guide ◽  
The Heat Transfer Coefficient

This paper presents a thermal investigation of the Integrated Combustor Vane concept for power generation gas turbines with individual can combustors. This concept has the potential to replace the high-pressure turbine’s first vanes by prolonged combustor walls. Experimental measurements are performed on a linear high-speed cascade consisting of two can combustors and two integrated vanes. The modularity of the facility allows for the testing at engine-realistic high turbulence levels, as well as swirl strengths with opposing swirl directions. The heat transfer characteristics of the integrated vanes are compared to conventional nozzle guide vanes. The experimental measurements are supported by detailed numerical simulations using the inhouse CFD code TBLOCK. Experimental as well as numerical results congruently indicate a considerable reduction of the heat transfer coefficient (HTC) on the integrated vanes surfaces and endwalls caused by a differing state of boundary layer thickness. The studies furthermore depict a slight, non-detrimental shift in the heat transfer coefficient distributions and the strength of the integrated vanes secondary flows as a result of engine-realistic combustor swirl.

A New Test Facility to Investigate Film Cooling on a Non-Axisymmetric Contoured Turbine Endwall: Part I — Introduction and Aerodynamic Measurements

2015 ◽  
Author(s):  
Franz Puetz ◽  
Johannes Kneer ◽  
Achmed Schulz ◽  
Hans-Joerg Bauer
Keyword(s):  
Heat Transfer ◽  
Flow Field ◽  
Pressure Distribution ◽  
Film Cooling ◽  
Gas Turbines ◽  
Guide Vane ◽  
Leading Edge ◽  
Suction Side ◽  
Test Facility ◽  
Endwall Contouring

An increased demand for lower emission of stationary gas turbines as well as civil aircraft engines has led to new, low emission combustor designs with less liner cooling and a flattened temperature profile at the outlet. As a consequence, the heat load on the endwall of the first nozzle guide vane is increased. The secondary flow field dominates the endwall heat transfer, which also contributes to aerodynamic losses. A promising approach to reduce these losses is non-axisymmetric endwall contouring. The effects of non-axisymmetric endwall contouring on heat transfer and film cooling are yet to be investigated. Therefore, a new cascade test rig has been set up in order to investigate endwall heat transfer and film cooling on both a flat and a non-axisymmetric contoured endwall. Aerodynamic measurements that have been made prior to the upcoming heat transfer investigation are shown. Periodicity and detailed vane Mach number distributions ranging from 0 to 50% span together with the static pressure distribution on the endwall give detailed information about the aerodynamic behavior and influence of the endwall contouring. The aerodynamic study is backed by an oil paint study, which reveals qualitative information on the effect of the contouring on the endwall flow field. Results show that the contouring has a pronounced effect on vane and endwall pressure distribution and on the endwall flow field. The local increase and decrease of velocity and the reduced blade loading towards the endwall is the expected behavior of the 3d contouring. So are the results of the oil paint visualization, which show a strong change of flow field in the leading edge region as well as that the contouring delays the horse shoe vortex hitting the suction side.

Aerothermal Performance of Shielded Vane Design

2017 ◽  
Vol 139 (11) ◽  
Author(s):  
Ioanna Aslanidou ◽  
Budimir Rosic
Keyword(s):  
Heat Transfer ◽  
Total Pressure ◽  
High Speed ◽  
Guide Vane ◽  
Leading Edge ◽  
Experimental Facility ◽  
Numerical Studies ◽  
Nozzle Guide Vane ◽  
Inlet Conditions ◽  
Nozzle Guide

This paper presents an experimental investigation of the concept of using the combustor transition duct wall to shield the nozzle guide vane leading edge. The new vane is tested in a high-speed experimental facility, demonstrating the improved aerodynamic and thermal performance of the shielded vane. The new design is shown to have a lower average total pressure loss than the original vane, and the heat transfer on the vane surface is overall reduced. The peak heat transfer on the vane leading edge–endwall junction is moved further upstream, to a region that can be effectively cooled as shown in previously published numerical studies. Experimental results under engine-representative inlet conditions showed that the better performance of the shielded vane is maintained under a variety of inlet conditions.

scholarly journals Investigation of Unsteady Flow Phenomena in First Vane Caused by Combustor Flow With Swirl

2016 ◽  
Author(s):  
Simon Jacobi ◽  
Cosimo Mazzoni ◽  
Krishan Chana ◽  
Budimir Rosic
Keyword(s):  
Gas Turbines ◽  
High Speed ◽  
Leading Edge ◽  
Transient Behavior ◽  
Horseshoe Vortex ◽  
Spanwise Direction ◽  
Flow Solver ◽  
Eddy Simulation ◽  
Flow Phenomena ◽  
Nozzle Guide

The flow at the combustor turbine interface of power generation gas turbines with can combustors is characterized by high and non-uniform turbulence levels, lengthscales and residual swirl. These complexities have a significant impact on the first vanes aerothermal performance and lead to challenges for an effective turbine design. To date, this design philosophy mostly assumed steady flow and thus largely disregards the intrinsic unsteadiness. This paper investigates the steady and unsteady effects of the combustor flow with swirl on the turbines first vanes. Experimental measurements are conducted on a high-speed linear cascade that comprises two can combustors and four nozzle guide vanes. The experimental results are supported by a Large Eddy Simulation performed with the inhouse CFD flow solver TBLOCK. The study reveals the highly unsteady nature of the flow in the first vane and its effect on the heat transfer. A persistent flow structure of concentrated vorticity is observed. It wraps around the unshielded vane’s leading edge at midspan and periodically oscillates in spanwise direction due to the interaction of the residual low-pressure swirl core and the vane’s potential field. Moreover, the transient behavior of the horseshoe-vortex system due to large fluctuations in incidence is demonstrated.

Influence of Combustor Flow With Swirl on Integrated Combustor Vane Concept Full-Stage Performance

2017 ◽  
Vol 140 (1) ◽  
Author(s):  
Simon Jacobi ◽  
Budimir Rosic
Keyword(s):  
Heat Transfer ◽  
Power Generation ◽  
Gas Turbines ◽  
Aerodynamic Loss ◽  
Inlet Swirl ◽  
Stage Performance ◽  
Performance Penalty ◽  
Nozzle Guide ◽  
Nozzle Guide Vanes ◽  
Stage Efficiency

The integrated combustor vane concept for power generation gas turbines with can combustors has been shown to have significant benefits compared to conventional nozzle guide vanes (NGV). Aerodynamic loss, heat transfer levels, and cooling requirements are reduced while stage efficiency is improved by approximately 1.5% (for a no-swirl scenario). Engine realistic combustor flow with swirl, however, leads to increased turning nonuniformity downstream of the integrated vanes. This paper thus illustrates the altered integrated vane stage performance caused by inlet swirl. The study shows a distinct performance penalty for the integrated vane rotor as a result of increased rotor incidence and the rotor's interaction with the residual swirl core. The stage efficiency advantage of the integrated combustor vane concept compared to the conventional design is thus reduced to 0.7%. It is furthermore illustrated how integrated vane profiling is suitable to reduce the turning variation across the span downstream of the vane, further improve stage efficiency (in this case by 0.23%) and thus mitigate the distinct impact of inlet swirl on integrated vane stage performance.

Effect of the Combustor Wall on the Aerothermal Field of a Nozzle Guide Vane

2018 ◽  
Vol 140 (5) ◽  
Author(s):  
Ioanna Aslanidou ◽  
Budimir Rosic
Keyword(s):  
Gas Turbines ◽  
High Speed ◽  
Guide Vane ◽  
Leading Edge ◽  
Flow Structures ◽  
Experimental Facility ◽  
Aerodynamic Loss ◽  
Nozzle Guide Vane ◽  
Nozzle Guide ◽  
Processing Techniques

In gas turbines with can combustors, the trailing edge (TE) of the combustor transition duct wall is found upstream of every second vane. This paper presents an experimental and numerical investigation of the effect of the combustor wall TE on the aerothermal performance of the nozzle guide vane. In the measurements carried out in a high-speed experimental facility, the wake of this wall is shown to increase the aerodynamic loss of the vane. On the other hand, the wall alters secondary flow structures and has a protective effect on the heat transfer in the leading edge-endwall junction, a critical region for component life. The different clocking positions of the vane relative to the combustor wall are tested experimentally and are shown to alter the aerothermal field. The experimental methods and processing techniques adopted in this work are used to highlight the differences between the different cases studied.

An Internal Heat Transfer Study in a Cooled Nozzle Guide Vane of a Linear Cascade

2014 ◽  
Author(s):  
Arun Kumar Pujari ◽  
Prasad B. V. S. S. Subrahmanyaa ◽  
Sitaram Nekkanti
Keyword(s):  
Heat Transfer ◽  
Surface Temperature ◽  
Film Cooling ◽  
Guide Vane ◽  
Internal Heat ◽  
Leading Edge ◽  
Internal Surface ◽  
Structure Variation ◽  
Nozzle Guide Vane ◽  
Nozzle Guide

Experimental and computational heat transfer investigations are reported in the interior mid span of the pressure surface of a Nozzle Guide Vane (NGV) subjected to combined impingement and film cooling. The study is carried out by considering a two dimensional cascade domain having four passages formed between the five vane each has a chord length of 228 mm and spacing (between the blades) of 200 mm. The vane internal surface is cooled by two impingement inserts namely front and aft impingement tubes. The front impingement tube is used to cool the internal side of the leading edge of the NGV whereas the aft impingement tube is used to cool mainly the mid span of the internal surface. The mass flow through the impingement chamber is varied for a fixed target plate distance to jet diameter ratio of 1.12. The surface temperature at the mid chord region was measured by liquid crystal technique. The surface temperature obtained from both experiments and computations are compared and the computationally obtained average heat transfer coefficient distribution along chord reported. The flow structure variation along the chord and its effect on Nusselt number distribution is presented. The computation is carried out by using Shear stress transport (SST) k-ω turbulence model in the ANSY FLUENT-14 flow solver.

Numerical Prediction of Film Cooling and Heat Transfer on the Leading Edge of a Rotating Blade in a 1-1/2 Turbine Stage

2004 ◽  
Author(s):  
Huitao Yang ◽  
Hamn-Ching Chen ◽  
Je-Chin Han ◽  
Hee-Koo Moon
Keyword(s):  
Heat Transfer ◽  
Film Cooling ◽  
Gas Turbines ◽  
Turbine Blades ◽  
Leading Edge ◽  
High Heat ◽  
Turbine Stage ◽  
Film Cooling Effectiveness ◽  
Rotating Blade ◽  
High Heat Transfer

In modern gas turbines, the blade leading edge region is one area that experiences high heat transfer due to the stagnation flow. Many cooling techniques have been applied to blades, so they can withstand these high heat loads; one of the common methods in cooling turbine blades is to apply film cooling. In the present study, numerical simulations were performed to predict the film cooling effectiveness and heat transfer coefficient on the leading edge of a rotating blade in a 1-1/2 turbine stage using a Reynolds stress turbulence model together with a non-equilibrium wall function. In addition, the unsteady characteristics of the film cooling and heat transfer at different time phases during a passing period were also investigated.

Influence of Combustor Flow With Swirl on Integrated Combustor Vane Concept Full-Stage Performance

2017 ◽  
Author(s):  
Simon Jacobi ◽  
Budimir Rosic
Keyword(s):  
Heat Transfer ◽  
Power Generation ◽  
Gas Turbines ◽  
Aerodynamic Loss ◽  
Inlet Swirl ◽  
Stage Performance ◽  
Performance Penalty ◽  
Nozzle Guide ◽  
Nozzle Guide Vanes ◽  
Stage Efficiency

The integrated combustor vane concept for power generation gas turbines with can combustors has been shown to have significant benefits compared to conventional nozzle guide vanes. Aerodynamic loss, heat transfer levels and cooling requirements are reduced while stage efficiency is improved by approximately 1.5% (for a no-swirl scenario). Engine realistic combustor flow with swirl however leads to increased turning non-uniformity downstream of the integrated vanes. This paper thus illustrates the altered integrated vane stage performance caused by inlet swirl. The study shows a distinct performance penalty for the integrated vane rotor as a result of increased rotor incidence and the rotor’s interaction with the residual swirl core. The stage efficiency advantage of the integrated combustor vane concept compared to the conventional design is thus reduced to 0.7%. It is furthermore illustrated how integrated vane profiling is suitable to reduce the turning variation across the span downstream of the vane, further improve stage efficiency (in this case by 0.23%) and thus mitigate the distinct impact of inlet swirl on integrated vane stage performance.

Sign in / Sign up

Export Citation Format

Share Document