Steady State and Transient CFD Studies on Aerodynamic Performance Validation of a High Pressure Turbine

2012 ◽  
Author(s):  
Sridhar Murari ◽  
Sathish Sunnam ◽  
Jong S. Liu
Keyword(s):  
High Pressure ◽  
Total Pressure ◽  
Pressure Ratio ◽  
Aerodynamic Performance ◽  
Detached Eddy Simulation ◽  
High Pressure Turbine ◽  
Predictive Capacity ◽  
Flow Angle ◽  
Analysis And Design ◽  
Eddy Simulation

With the advent of fast computers and availability of less costly memory resources, computational fluid dynamics (CFD) has emerged as a powerful tool for the design and analysis of flow and heat transfer of high pressure turbine stages. CFD gives an insight in to flow patterns that are difficult, expensive or impossible to study using experimental techniques. However, the application of CFD depends on its accuracy and reliability. This requires the CFD code to be validated with laboratory measurements to ensure its predictive capacity. In the continual effort to improve analysis and design techniques, Honeywell has been investigating in the use of CFD to predict the aerodynamic performance of a high pressure turbine. Reynolds Averaged Navier Stokes (RANS), unsteady models like detached eddy simulation (DES), large eddy simulation (LES), and Scale Adaptive Simulation (SAS) are used to predict the aerodynamic performance of a high pressure turbine. Mixing plane approach is used to address the flow data transport across the stationary interface in RANS simulation. The film holes on blade surface and end walls for all the analysis are modeled by using actual film hole modeling technique. The validation is accomplished with the test results of a high pressure turbine, Energy Efficient Engine (E3). The aerodynamic performance data at design point, typical off-design points are taken as test cases for the validation study. One dimensional performance parameters such as corrected mass flow rate, total pressure ratio, cycle efficiency, and two dimensional spanwise distributions of total pressure, total temperature and flow angle that are obtained from CFD results are compared with test data. Streamlines and flow field results at different measurement planes are presented to understand the aerodynamic behavior.

CFD Aerodynamic Performance Validation of a Two-Stage High Pressure Turbine

2011 ◽  
Author(s):  
Murari Sridhar ◽  
Sathish Sunnam ◽  
Shraman Goswami ◽  
Jong S. Liu
Keyword(s):  
High Pressure ◽  
Total Pressure ◽  
Pressure Ratio ◽  
Aerodynamic Performance ◽  
High Pressure Turbine ◽  
Two Stage ◽  
Design Point ◽  
Analysis And Design ◽  
Improve Analysis ◽  
Performance Validation

In the continual effort to improve analysis and design techniques, Honeywell is investigating on the use of CFD to predict the aerodynamic performance of a high pressure turbine. The present study has a two fold objective. The first objective is to validate the commercially available CFD codes for aerodynamic performance prediction of a two-stage high pressure turbine at design and off-design points. The other objective is to establish guidelines to help the designer to successfully.set-up and execute the suitable CFD model analysis. The validation to model the stage interfaces is performed with three different types of approaches such as Mixing Plane approach, Frozen Rotor approach and NonLinear Harmonic approach. The film holes on the blade surface, hub and the shroud walls are modeled by using source term cooling and actual film hole modeling techniques for all the analysis. The validation is accomplished with the test results of a two-stage high pressure turbine, Energy Efficient Engine (E3). The aerodynamic performance data at a design point and typical off-design point are taken as test cases for the validation study. One dimensional performance parameters such as corrected mass flow rate, total pressure ratio, cycle efficiency along with two dimensional spanwise distribution of total pressure, total temperature which are obtained from CFD results are compared with test data. Flow field results are presented to understand the aerodynamic behavior.

DDES Analysis of Wake Vortex Related Unsteadiness and Losses in the Environment of High-Pressure Turbine Stage

2017 ◽  
Author(s):  
Dun Lin ◽  
Xinrong Su ◽  
Xin Yuan
Keyword(s):  
High Pressure ◽  
Boundary Layer Transition ◽  
Wake Vortex ◽  
High Fidelity ◽  
Strong Impact ◽  
Detached Eddy Simulation ◽  
High Pressure Turbine ◽  
Layer Transition ◽  
Eddy Simulation ◽  
Delayed Detached Eddy Simulation

In this work, the flows inside the high pressure turbine (HPT) vane and stage are studied with the help of a high-fidelity delayed detached eddy simulation (DDES) code. This work intends to study the fundamental nozzle/blade interaction with special attention paid to the development and transportation of the vane wake vortex. There are two motivations for this work. On the one hand, the high pressure turbine operates at both transonic Mach numbers and high Reynolds numbers, which imposes a great challenge to modern computational fluid dynamics (CFD), especially for scale-resolved simulation methods. An accurate and efficient high-fidelity CFD solver is very important for a thorough understanding of the flow physics and the design of more efficient HPT. On the other hand, the periodic wake vortex shedding is an important origin of turbine losses and unsteadiness. The wake and vortex not only cause losses themselves, but also interact with the shock wave (under transonic working condition), pressure waves, and have a strong impact on the downstream blade surface (affecting boundary layer transition and heat transfer). Built on one of our previous DDES simulations of a HPT vane VKI LS89, this work further investigates the development and length characteristics of the wake vortex, provides explanations of the length characteristics and reveals the transportation of the wake vortex into the downstream rotor passage along with its impact on the downstream aero-thermal performance.

Design and Test Results of a Ultra High Loaded Single Stage High Pressure Turbine

2013 ◽  
Author(s):  
Harjit S. Hura ◽  
Scott Carson ◽  
Rob Saeidi ◽  
Hyoun-Woo Shin ◽  
Paul Giel
Keyword(s):  
High Pressure ◽  
Total Pressure ◽  
High Speed ◽  
Pressure Ratio ◽  
Single Stage ◽  
Test Results ◽  
High Pressure Turbine ◽  
Technology Program ◽  
High Pressure Ratio ◽  
Expected Performance

This paper describes the engine and rig design, and test results of an ultra-highly loaded single stage high pressure turbine. In service aviation single stage HPTs typically operate at a total-to-total pressure ratio of less than 4.0. At higher pressure ratios or energy extraction the nozzle and blade both have regions of supersonic flow and shock structures which, if not mitigated, can result in a large loss in efficiency both in the turbine itself and due to interaction with the downstream component which may be a turbine center frame or a low pressure turbine. Extending the viability of the single stage HPT to higher pressure ratios is attractive as it enables a compact engine with less weight, and lower initial and maintenance costs as compared to a two stage HPT. The present work was performed as part of the NASA UEET (Ultra-Efficient Engine Technology) program from 2002 through 2005. The goal of the program was to design and rig test a cooled single stage HPT with a pressure ratio of 5.5 with an efficiency at least two points higher than the state of the art. Preliminary design tools and a design of experiments approach were used to design the flow path. Stage loading and through-flow were set at appropriate levels based on prior experience on high pressure ratio single stage turbines. Appropriate choices of blade aspect ratio, count, and reaction were made based on comparison with similar HPT designs. A low shock blading design approach was used to minimize the shock strength in the blade during design iterations. CFD calculations were made to assess performance. The HPT aerodynamics and cooling design was replicated and tested in a high speed rig at design point and off-design conditions. The turbine met or exceeded the expected performance level based on both steady state and radial/circumferential traverse data. High frequency dynamic total pressure measurements were made to understand the presence of unsteadiness that persists in the exhaust of a transonic turbine.

Delayed Detached Eddy Simulation of a Full 3-Dimensional High-Pressure Turbine Stage: Part I — Flow Topology

2018 ◽  
Author(s):  
Dun Lin ◽  
Xiutao Bian ◽  
Xin Yuan ◽  
Xinrong Su
Keyword(s):  
High Pressure ◽  
Horseshoe Vortex ◽  
Wake Vortex ◽  
High Fidelity ◽  
Detached Eddy Simulation ◽  
Tip Leakage Flow ◽  
High Pressure Turbine ◽  
Flow Topology ◽  
Eddy Simulation ◽  
Delayed Detached Eddy Simulation

In this work, the flow inside a high pressure turbine (HPT) stage is studied with the help of a high-fidelity delayed detached eddy simulation (DDES) code. This work intends to study the flow topology in the HPT stage. There are two motivations for this work: On the one hand, high pressure turbines operates at both transonic Mach numbers and high Reynolds numbers, which imposes a challenge to modern computational fluid dynamics (CFD), especially for scale-resolved simulation methods. An accurate and efficient high-fidelity CFD solver is very important for a thorough understanding of the flow physics and the design of higher-efficient HPT. On the other hand, the wake vortex shedding and tip-leakage flow are important origins of turbine losses and unsteadiness. Built on our previous DDES simulations of HPT vane and stage, this work further investigates the flow in a full 3-dimension HPT stage. The flow topology in the HPT stage is delineated by Q-criterion iso-surfaces. The development of the horseshoe vortex and its interaction with induced vortex and wake vortex is discussed. The wake vortex transportation especially its interaction with the rotor horseshoe vortex is investigated. The flow structures in the tip clearance region are also revealed.

Migration of Combustor Exit Profiles Through High Pressure Turbine Vanes

2007 ◽  
Author(s):  
M. D. Barringer ◽  
M. D. Polanka ◽  
J. P. Clark ◽  
P. J. Koch ◽  
K. A. Thole
Keyword(s):  
High Pressure ◽  
Secondary Flow ◽  
Total Pressure ◽  
Secondary Flows ◽  
Working Fluid ◽  
Outer Diameter ◽  
High Pressure Turbine ◽  
Flow Angle ◽  
Radial Temperature ◽  
Turbine Vane

The high pressure turbine stage within gas turbine engines is exposed to combustor exit flows that are nonuniform in both stagnation pressure and temperature. These highly turbulent flows typically enter the first stage vanes with significant spatial gradients near the inner and outer diameter endwalls. These gradients can result in secondary flow development within the vane passage that is different than what classical secondary flow models predict. The heat transfer between the working fluid and the turbine vane surface and endwalls is directly related to the secondary flows. The goal of the current study was to examine the migration of different inlet radial temperature and pressure profiles through the high turbine vane of a modern turbine engine. The tests were performed using an inlet profile generator located in the Turbine Research Facility (TRF) at the Air Force Research Laboratory (AFRL). Comparisons of area-averaged radial exit profiles are reported as well as profiles at three vane pitch locations to document the circumferential variation in the profiles. The results show that the shape of the total pressure profile near the endwalls at the inlet of the vane can alter the redistribution of stagnation enthalpy through the airfoil passage significantly. Total pressure loss and exit flow angle variations are also examined for the different inlet profiles.

Single Passage Detached Eddy Simulation of a Centrifugal Compressor Stage Using the Time Transformation Method

2015 ◽  
Author(s):  
Jason A. Bourgeois ◽  
Jason C. Nichols ◽  
Guilherme H. Watson ◽  
Robert J. Martinuzzi
Keyword(s):  
Centrifugal Compressor ◽  
Total Pressure ◽  
Pressure Ratio ◽  
Compressor Stage ◽  
Detached Eddy Simulation ◽  
Trailing Edge ◽  
Single Passage ◽  
Eddy Simulation ◽  
Pressure Distributions ◽  
Total Pressure Ratio

A subsonic rear stage centrifugal compressor (designed as the last compressor stage of an aero-engine following a multi-stage axial compressor) was simulated as a single passage using Detached Eddy Simulation (DES) and circumferential time-inclination to enforce periodic boundary conditions according to the machine rotor-stator pitch ratio. The transient averaged statistics obtained with DES are compared to those of a standard steady mixing plane SST RANS simulation, an unsteady circumferential time-inclination SST URANS simulation and two-component non-intrusive Laser Doppler Velocimetry (LDV) measurements conducted in a centrifugal compressor test rig. The LDV and DES were carried out at the design point of the compressor. Significant discrepancies were found particularly in the unloading at the trailing edge of the impeller and the balancing of the diffusion throughout the stage, however the overall stage performance predictions were strikingly similar between the various turbulence modelling methods indicating that they are not particularly sensitive to the observed aerodynamic differences. The discrepancies observed do affect the ratio of loading between the impeller and diffuser, and could become exaggerated particularly at off-design conditions when components are not as well matched. At design, the DES showed a 1.6% lower total-to-total pressure ratio in the impeller compared to RANS (1.4% compared to URANS), and 0.9% lower in stage total-to-total pressure ratio (0.2% compared to URANS). Trailing edge base pressure distributions show a larger deficit in the RANS wake in comparison to the DES, and pressure distributions show strong blade-to-blade variations in the steady RANS results in the near-trailing edge region, whereas the averaged DES results show a much faster diffusion of the blade-to-blade and spanwise gradients which was found to be in agreement with LDV velocity field measurements. The higher diffusion in the DES is due to higher Reynolds stresses predicted in this area compared to standard RANS.

Migration of Combustor Exit Profiles Through High Pressure Turbine Vanes

2009 ◽  
Vol 131 (2) ◽  
Author(s):  
M. D. Barringer ◽  
K. A. Thole ◽  
M. D. Polanka ◽  
J. P. Clark ◽  
P. J. Koch
Keyword(s):  
High Pressure ◽  
Secondary Flow ◽  
Total Pressure ◽  
Secondary Flows ◽  
Working Fluid ◽  
Outer Diameter ◽  
High Pressure Turbine ◽  
Flow Angle ◽  
Radial Temperature ◽  
Turbine Vane

The high pressure turbine stage within gas turbine engines is exposed to combustor exit flows that are nonuniform in both stagnation pressure and temperature. These highly turbulent flows typically enter the first stage vanes with significant spatial gradients near the inner and outer diameter endwalls. These gradients can result in secondary flow development within the vane passage that is different than what classical secondary flow models predict. The heat transfer between the working fluid and the turbine vane surface and endwalls is directly related to the secondary flows. The goal of the current study was to examine the migration of different inlet radial temperature and pressure profiles through the high turbine vane of a modern turbine engine. The tests were performed using an inlet profile generator located in the Turbine Research Facility at the Air Force Research Laboratory. Comparisons of area-averaged radial exit profiles are reported as well as profiles at three vane pitch locations to document the circumferential variation in the profiles. The results show that the shape of the total pressure profile near the endwalls at the inlet of the vane can alter the redistribution of stagnation enthalpy through the airfoil passage significantly. Total pressure loss and exit flow angle variations are also examined for the different inlet profiles.

Zonal Detached-Eddy Simulation Approach vs. URANS for the Prediction of the Flow Field Through a Low Pressure Vane Located Downstream of a Transonic High Pressure Turbine

2015 ◽  
Author(s):  
Pierre Gougeon ◽  
Ghislaine Ngo Boum
Keyword(s):  
High Pressure ◽  
Flow Field ◽  
Computational Cost ◽  
Low Pressure ◽  
Good Alternative ◽  
Navier Stokes ◽  
Detached Eddy Simulation ◽  
High Pressure Turbine ◽  
Eddy Simulation ◽  
Numerical Predictions

The present work aims at studying the aerodynamic flow field within the first Low Pressure Vane (LPV) located downstream of a transonic High Pressure Turbine (HPT). A Zonal Detached-Eddy Simulation (ZDES) which is an hybrid URANS (Unsteady Reynolds Averaged Navier-Stokes)-DES approach, appears as a good alternative in terms of computational cost and quality of turbulent phenomena description when it comes to the capture of key parameters of losses generation in a LPV. ZDES is used on the LPV and the unsteady periodic flow field coming from the upstream HPT is modelled through a nonuniform rotating inlet boundary condition. The result is compared to a URANS simulation carried out with the same mesh and numerical parameters: this enables to quantify the differences and to state on the benefit of an advanced turbulent approach. Turbulent mechanisms are assessed with the computation of the power spectral density at different locations in the domain. To complete the analysis, the two numerical predictions are compared to experimental data. Wakes and vortices evolutions are studied in detail making it possible to put them into perspective with the aerodynamic losses generated in the LPV.

A dynamic probabilistic design method for blade-tip radial running clearance of aeroengine high-pressure turbine

2014 ◽  
Vol 229 (10) ◽  
pp. 1861-1872 ◽  
Author(s):  
Cheng-Wei Fei ◽  
Wen-Zhong Tang ◽  
Guang-chen Bai ◽  
Zhi-Ying Chen
Keyword(s):  
High Pressure ◽  
Response Surface ◽  
Response Surface Method ◽  
Probabilistic Analysis ◽  
High Reliability ◽  
Probabilistic Design ◽  
High Pressure Turbine ◽  
Analysis And Design ◽  
Surface Method ◽  
Blade Tip

Around the engineering background of the probabilistic design of high-pressure turbine (HPT) blade-tip radial running clearance (BTRRC) which conduces to the high-performance and high-reliability of aeroengine, a distributed collaborative extremum response surface method (DCERSM) was proposed for the dynamic probabilistic analysis of turbomachinery. On the basis of investigating extremum response surface method (ERSM), the mathematical model of DCERSM was established. The DCERSM was applied to the dynamic probabilistic analysis of BTRRC. The results show that the blade-tip radial static clearance δ = 1.82 mm is advisable synthetically considering the reliability and efficiency of gas turbine. As revealed by the comparison of three methods (DCERSM, ERSM, and Monte Carlo method), the DCERSM reshapes the possibility of the probabilistic analysis for turbomachinery and improves the computational efficiency while preserving computational accuracy. The DCERSM offers a useful insight for BTRRC dynamic probabilistic analysis and optimization. The present study enrichs mechanical reliability analysis and design theory.

Sign in / Sign up

Export Citation Format

Share Document