Effect of Combustor Swirl on Transonic High Pressure Turbine Efficiency

2013 ◽  
Vol 136 (1) ◽  
Author(s):  
Paul F. Beard ◽  
Andy D. Smith ◽  
Thomas Povey
Keyword(s):  
High Pressure ◽  
Computational Study ◽  
Pressure Ratio ◽  
High Pressure Turbine ◽  
Turbine Efficiency ◽  
Baseline Case ◽  
Inlet Swirl ◽  
Computational Fluid Dynamics Cfd ◽  
External Flows ◽  
The Eu

This paper presents an experimental and computational study of the effect of inlet swirl on the efficiency of a transonic turbine stage. The efficiency penalty is approximately 1%, but it is argued that this could be recovered by correct design. There are attendant changes in capacity, work function, and stage total-to-total pressure ratio, which are discussed in detail. Experiments were performed using the unshrouded MT1 high-pressure turbine installed in the Oxford Turbine Research Facility (OTRF) (formerly at QinetiQ Farnborough): an engine scale, short duration, rotating transonic facility, in which M, Re, Tgas/Twall, and N/T01 are matched to engine conditions. The research was conducted under the EU Turbine Aero-Thermal External Flows (TATEF II) program. Turbine efficiency was experimentally determined to within bias and precision uncertainties of approximately ±1.4% and ±0.2%, respectively, to 95% confidence. The stage mass flow rate was metered upstream of the turbine nozzle, and the turbine power was measured directly using an accurate strain-gauge based torque measurement system. The turbine efficiency was measured experimentally for a condition with uniform inlet flow and a condition with pronounced inlet swirl. Full stage computational fluid dynamics (CFD) was performed using the Rolls-Royce Hydra solver. Steady and unsteady solutions were conducted for both the uniform inlet baseline case and a case with inlet swirl. The simulations are largely in agreement with the experimental results. A discussion of discrepancies is given.

Impact of Severe Temperature Distortion on Turbine Efficiency

2012 ◽  
Vol 135 (1) ◽  
Author(s):  
Paul F. Beard ◽  
Andy Smith ◽  
Thomas Povey
Keyword(s):  
Computational Study ◽  
Measurement Techniques ◽  
Inlet Temperature ◽  
Turbine Efficiency ◽  
Computational Fluid Dynamics Cfd ◽  
External Flows ◽  
Torque Transducer ◽  
Formed Part ◽  
Low Uncertainty ◽  
The Eu

This paper presents an experimental and computational study of the effect of severe inlet temperature distortion (hot streaks) on the efficiency of the MT1 HP turbine, which is a highly-loaded unshrouded transonic design. The experiments were performed in the Oxford Turbine Research Facility (OTRF) (formerly the TTF at QinetiQ Farnborough): an engine scale, short duration, rotating transonic facility, in which M, Re, Tgas/Twall and N/T01 are matched to engine conditions. The research formed part of the EU Turbine Aero-Thermal External Flows (TATEF II) program. An advanced second generation temperature distortion simulator was developed for this investigation, which allows both radial and circumferential temperature profiles to be simulated. A pronounced profile was used for this study. The system was novel in that it was designed to be compatible with an efficiency measurement system which was also developed for this study. To achieve low uncertainty (bias and precision errors of approximately 1.5% and 0.2% respectively, to 95% confidence), the mass flow rate of the hot and cold streams used to simulate temperature distortion were independently metered upstream of the turbine nozzle using traceable measurement techniques. Turbine power was measured directly with an accurate torque transducer. The efficiency of the test turbine was evaluated experimentally for a uniform inlet temperature condition, and with pronounced temperature distortion. Mechanisms for observed changes in the turbine exit flow field and efficiency are discussed. The data are compared in terms of flow structure to full stage computational fluid dynamics (CFD) performed using the Rolls Royce Hydra code.

Numerical Investigation of High-Pressure Turbine Environment Effects on the Prediction of Aerothermal Performances

2012 ◽  
Author(s):  
Fabien Wlassow ◽  
Francis Leboeuf ◽  
Gilles Leroy ◽  
Nicolas Gourdain ◽  
Ghislaine Ngo Boum
Keyword(s):  
High Pressure ◽  
Entropy Production ◽  
Rotor Blade ◽  
Suction Side ◽  
Thermal Coupling ◽  
High Pressure Turbine ◽  
Turbulent Dissipation ◽  
Turbine Efficiency ◽  
Baseline Case ◽  
Hot Streak

Aerothermal prediction for the high-pressure turbine is challenging because of the complex environment that interacts with the turbine: hot-streak migration, unsteady flow phenomena, fluid/solid thermal coupling and technological details (squealer tip, coolant ejections, fillets, etc.). There is a need to compare their relative impacts on the blade temperature and turbine efficiency prediction. This is the main purpose of this paper. URANS simulations of the flow have been performed with a structured flow solver in a one stage high-pressure turbine. The baseline simulation takes into account the squealer tip and an inlet condition representative of a hot streak generated by the combustion chamber. Other technological details (coolant ejections and fillets) and fluid/solid thermal coupling on the rotor blade are alternatively considered in the simulation in order to quantify their relative contribution. The Chimera technique is used to ease the integration of technological details. The conjugate heat transfer (CHT) problem is solved by means of a code coupling where fluxes and temperatures are exchanged at the blade surface between the fluid dynamics solver and the solid thermal code. Results shows that rotor blade fillets have a little impact on both the blade temperature and the turbine efficiency (less than 1%). On the contrary, taking into account external cooling leads to a modification of radial distribution of loss and loading coefficients and reduces the efficiency by 2%. The blade temperature is also impacted, mainly on the suction side where differences of several per cent with the baseline case are observed. Fluid/solid coupling mainly affects the blade temperature prediction by homogenizing it which induces differences around 3% with the baseline case. To complete the analysis, a post-processing that includes a computation of local entropy production terms is used. It shows that the entropy production is mainly due to turbulent dissipation and allows to identify the reduction of efficiency of the case with cooling as an additional production of entropy where the cooling flow mixes with the main flow.

Impact of Severe Temperature Distortion on Turbine Efficiency

2011 ◽  
Author(s):  
Paul F. Beard ◽  
Andy Smith ◽  
Thomas Povey
Keyword(s):  
Computational Study ◽  
Measurement Techniques ◽  
Inlet Temperature ◽  
Temperature Profiles ◽  
Turbine Efficiency ◽  
External Flows ◽  
Torque Transducer ◽  
Formed Part ◽  
Low Uncertainty ◽  
The Eu

This paper presents an experimental and computational study of the effect of severe inlet temperature distortion (hot streaks) on the efficiency of the MT1 HP turbine, which is a highly-loaded unshrouded transonic design. The experiments were performed in the Oxford Turbine Research Facility (OTRF) (formerly the TTF at QinetiQ Farnborough): an engine scale, short duration, rotating transonic facility, in which M, Re, and Tgas/Twall and N/T01 are matched to engine conditions. The research formed part of the EU Turbine Aero-Thermal External Flows (TATEF II) programme. An advanced second generation temperature distortion simulator was developed for this investigation, which allows both radial and circumferential temperature profiles to be simulated. A pronounced profile was used for this study. The system was novel in that it was designed to be compatible with an efficiency measurement system which was also developed for this study. To achieve low uncertainty (bias and precision errors of approximately 1.5 per cent and 0.2 per cent respectively, to 95 per cent confidence), the mass flow rate of the hot and cold streams used to simulate temperature distortion were independently metered upstream of the turbine nozzle using traceable measurement techniques. Turbine power was measured directly with an accurate torque transducer. The efficiency of the test turbine was evaluated experimentally for a uniform inlet temperature condition, and with pronounced temperature distortion. Mechanisms for observed changes in the turbine exit flow field and efficiency are discussed. The data are compared in terms of flow structure to full stage CFD performed using the Rolls Royce Hydra code.

Experimental and computational fluid dynamics investigation of the efficiency of an unshrouded transonic high pressure turbine

2011 ◽  
Vol 225 (8) ◽  
pp. 1166-1179 ◽  
Author(s):  
P F Beard ◽  
A D Smith ◽  
T Povey
Keyword(s):  
Fluid Dynamics ◽  
Computational Fluid Dynamics ◽  
Short Duration ◽  
Computational Study ◽  
Experimental Result ◽  
Test Facility ◽  
Turbine Efficiency ◽  
External Flows ◽  
Formed Part ◽  
The Eu

This article presents an experimental and computational study of the efficiency of an unshrouded transonic turbine. This research formed part of the EU Turbine Aero-Thermal External Flows II programme. The experiments were performed in the Oxford Turbine Research Facility (previously the Turbine Test Facility at QinetiQ, Farnborough). This facility is an engine scale, short duration, rotating transonic facility, in which M, Re, [Formula: see text], and [Formula: see text] are matched to engine conditions. For these experiments, the MT1 turbine stage was installed. Historically, turbine efficiency measurements are conducted in steady state adiabatic facilities. However, short-duration facilities allow simultaneous aerodynamic and heat transfer measurements with a significant reduction in cost. An efficiency measurement system was developed for this investigation, and this is briefly described. The system allows efficiency to be evaluated to bias and precision errors of approximately ±1.45 per cent and ±0.16 per cent, respectively, to 95 per cent confidence. The results of accurate area surveys of the turbine inlet and exit flows are presented and discussed. At the turbine exit, data were taken at two traverse planes, approximately 0.5 and 4.5 rotor axial chords downstream of the rotor. The turbine efficiency was experimentally evaluated based on the data at both planes, using a number of mixing models, which are discussed and compared. The experimental result of turbine efficiency is also compared to that estimated from a mean-line prediction. Full-stage steady and unsteady computational fluid dynamics of the experiment using the Rolls-Royce HYDRA code was conducted and is also presented. The predicted and measured rotor exit flow-fields are compared at both downstream traverse planes.

CFD Heat Transfer Predictions for a High-Pressure Turbine Stage

2004 ◽  
Author(s):  
James A. Tallman
Keyword(s):  
Heat Transfer ◽  
High Pressure ◽  
Turbulence Modeling ◽  
Pressure Ratio ◽  
Numerical Procedure ◽  
Navier Stokes ◽  
Turbine Stage ◽  
Temperature Ratio ◽  
High Pressure Turbine ◽  
Computational Fluid Dynamics Cfd

Computational Fluid Dynamics (CFD) was used to predict the turbine airfoil heat transfer for the high-pressure vane and high-pressure blade of a modern, one and one half stage turbine at its correct scale. Airfoil pressure and heat transfer measurements were recently obtained for the turbine in a transient shock tunnel facility, which allows for the replication of the actual engine turbine’s design corrected speed, pressure ratio, and gas-to-metal temperature ratio. A 3-D, compressible, Reynolds-averaged Navier-Stokes CFD solver with k-ω turbulence modeling was used for the CFD predictions. The turbulence model’s implementation into the numerical procedure was modified slightly, in order to better capture the model’s intended near-wall behavior and resolve the heat transfer prediction. Both the high-pressure vane and high-pressure blade were computed as steady-state flows and for two different turbine Reynolds number settings. Overall, the predictions compare very favorably with the measurement for both pressure and heat transfer at the mid-span location. A discussion of the features of the airfoil heat transfer distribution is included.

Time-Averaged and Time-Accurate Aerodynamic Effects of Forward Rotor Cavity Purge Flow for a High-Pressure Turbine: Part I—Analytical and Experimental Comparisons

2012 ◽  
Author(s):  
Brian R. Green ◽  
Randall M. Mathison ◽  
Michael G. Dunn
Keyword(s):  
High Pressure ◽  
Flow Field ◽  
Film Cooling ◽  
Pressure Ratio ◽  
Three Dimensional ◽  
Unsteady Aerodynamics ◽  
Flow Path ◽  
Field Analysis ◽  
High Pressure Turbine ◽  
Purge Flow

The effect of rotor purge flow on the unsteady aerodynamics of a high-pressure turbine stage operating at design corrected conditions has been investigated both experimentally and computationally. The experimental configuration consisted of a single-stage high-pressure turbine with a modern film-cooling configuration on the vane airfoil as well as the inner and outer end-wall surfaces. Purge flow was introduced into the cavity located between the high-pressure vane and the high-pressure disk. The high-pressure blades and the downstream low-pressure turbine nozzle row were not cooled. All hardware featured an aerodynamic design typical of a commercial high-pressure ratio turbine, and the flow path geometry was representative of the actual engine hardware. In addition to instrumentation in the main flow path, the stationary and rotating seals of the purge flow cavity were instrumented with high frequency response, flush-mounted pressure transducers and miniature thermocouples to measure flow field parameters above and below the angel wing. Predictions of the time-dependent flow field in the turbine flow path were obtained using FINE/Turbo, a three-dimensional, Reynolds-Averaged Navier-Stokes CFD code that had the capability to perform both steady and unsteady analysis. The steady and unsteady flow fields throughout the turbine were predicted using a three blade-row computational model that incorporated the purge flow cavity between the high-pressure vane and disk. The predictions were performed in an effort to mimic the design process with no adjustment of boundary conditions to better match the experimental data. The time-accurate predictions were generated using the harmonic method. Part I of this paper concentrates on the comparison of the time-averaged and time-accurate predictions with measurements in and around the purge flow cavity. The degree of agreement between the measured and predicted parameters is described in detail, providing confidence in the predictions for flow field analysis that will be provided in Part II.

scholarly journals The Design and Evaluation of a High Pressure Ratio Radial Turbine

1992 ◽  
Author(s):  
K. R. Pullen ◽  
N. C. Baines ◽  
S. H. Hill
Keyword(s):  
High Pressure ◽  
High Speed ◽  
Pressure Ratio ◽  
Performance Measurements ◽  
Turbine Engine ◽  
High Pressure Ratio ◽  
Turbine Efficiency ◽  
Wide Range ◽  
Dimensional Parameters ◽  
Very High

A single stage, high speed, high pressure ratio radial inflow turbine was designed for a single shaft gas turbine engine in the 200 kW power range. A model turbine has been tested in a cold rig facility with correct simulation of the important non-dimensional parameters. Performance measurements over a wide range of operation were made, together with extensive volute and exhaust traverses, so that gas velocities and incidence and deviation angles could be deduced. The turbine efficiency was lower than expected at all but the lowest speed. The rotor incidence and exit swirl angles, as obtained from the rig test data, were very similar to the design assumptions. However, evidence was found of a region of separation in the nozzle vane passages, presumably caused by a very high curvature in the endwall just upstream of the vane leading edges. The effects of such a separation are shown to be consistent with the observed performance.

Development of New Single and High-Density Heat-Flux Gauges for Unsteady Heat Transfer Measurements for a Rotating Transonic Turbine

2020 ◽  
Author(s):  
Richard Celestina ◽  
Spencer Sperling ◽  
Louis Christensen ◽  
Randall Mathison ◽  
Hakan Aksoy ◽  
...  
Keyword(s):  
Heat Transfer ◽  
Heat Flux ◽  
High Pressure ◽  
Pressure Ratio ◽  
High Density ◽  
Secondary Flows ◽  
Single Stage ◽  
High Pressure Turbine ◽  
Transonic Turbine ◽  
New Generation

Abstract This paper presents the development and implementation of a new generation of double-sided heat-flux gauges at The Ohio State University Gas Turbine Laboratory (GTL) along with heat transfer measurements for film-cooled airfoils in a single-stage high-pressure transonic turbine operating at design corrected conditions. Double-sided heat flux gauges are a critical part of turbine cooling studies, and the new generation improves upon the durability and stability of previous designs while also introducing high-density layouts that provide better spatial resolution. These new customizable high-density double-sided heat flux gauges allow for multiple heat transfer measurements in a small geometric area such as immediately downstream of a row of cooling holes on an airfoil. Two high-density designs are utilized: Type A consists of 9 gauges laid out within a 5 mm by 2.6 mm (0.20 inch by 0.10 inch) area on the pressure surface of an airfoil, and Type B consists of 7 gauges located at points of predicted interest on the suction surface. Both individual and high-density heat flux gauges are installed on the blades of a transonic turbine experiment for the second build of the High-Pressure Turbine Innovative Cooling program (HPTIC2). Run in a short duration facility, the single-stage high-pressure turbine operated at design-corrected conditions (matching corrected speed, flow function, and pressure ratio) with forward and aft purge flow and film-cooled blades. Gauges are placed at repeated locations across different cooling schemes in a rainbow rotor configuration. Airfoil film-cooling schemes include round, fan, and advanced shaped cooling holes in addition to uncooled airfoils. Both the pressure and suction surfaces of the airfoils are instrumented at multiple wetted distance locations and percent spans from roughly 10% to 90%. Results from these tests are presented as both time-average values and time-accurate ensemble averages in order to capture unsteady motion and heat transfer distribution created by strong secondary flows and cooling flows.

A Novel Hybrid Seal: Design and Experimental Validation on a High Pressure Rotordynamic Test Rig

2021 ◽  
Author(s):  
Giuseppe Vannini ◽  
Benjamin Defoy ◽  
Manjush Ganiger ◽  
Carlo Mazzali
Keyword(s):  
High Pressure ◽  
Pressure Ratio ◽  
Test Rig ◽  
Rotordynamic Coefficients ◽  
Experimental Activity ◽  
Seal Design ◽  
Piston Seal ◽  
Delivery Pressure ◽  
Inlet Swirl ◽  
Primary Focus

Abstract The design and experimental activity presented in this paper is related to a novel hybrid seal which is intended to work as a balance piston seal in an AMBs levitated high-pressure (about 300 bar delivery pressure) motor-compressor. The typical solution adopted for balance piston application is a damper seal (e.g. honeycomb seal), as the rotordynamic stability is a primary focus. However, due to interactions between the AMB controller and seal high stiffness level, the aforementioned selection is not so straightforward. After a review of the state of the art it was found that a combination of some conventional geometries (e.g. labyrinth and honeycomb) can be adopted to achieve the desired target. The design was done using a novel tool combining the validated bulk flow codes for each geometry. Moreover, a CFD analysis, based on some literature references, was carried out as a final verification of the design. The experimental activity was then performed at the Authors’ internal seal test rig. As in typical rotordynamic seal testing activity, the operating parameters leveraged to explore performance sensitivity are rotational speed, inlet pressure, pressure ratio and inlet swirl level. The outcome was satisfactory both in terms of leakage and rotordynamic coefficients.

Sign in / Sign up

Export Citation Format

Share Document