scholarly journals Analysis of the effect of intermittency in a high-pressure turbine blade

2020 ◽  
Vol 32 (9) ◽  
pp. 095101
Author(s):  
D. Dupuy ◽  
L. Gicquel ◽  
N. Odier ◽  
F. Duchaine ◽  
T. Arts
Keyword(s):  
High Pressure ◽  
Turbine Blade ◽  
High Pressure Turbine

scholarly journals Machine Learning for Turbulence Model Development Using a High-Fidelity HPT Cascade Simulation

2017 ◽  
Author(s):  
Jack Weatheritt ◽  
Richard Pichler ◽  
Richard D. Sandberg ◽  
Gregory Laskowski ◽  
Vittorio Michelassi
Keyword(s):  
High Pressure ◽  
Evolutionary Algorithm ◽  
Turbine Blade ◽  
A Priori ◽  
Model Development ◽  
Boussinesq Approximation ◽  
High Pressure Turbine ◽  
Stress Strain ◽  
Non Linear ◽  
Anisotropy Tensor

The validity of the Boussinesq approximation in the wake behind a high-pressure turbine blade is explored. We probe the mathematical assumptions of such a relationship by employing a least-squares technique. Next, we use an evolutionary algorithm to modify the anisotropy tensor a priori using highly resolved LES data. In the latter case we build a non-linear stress-strain relationship. Results show that the standard eddy-viscosity assumption underpredicts turbulent diffusion and is theoretically invalid. By increasing the coefficient of the linear term, the farwake prediction shows minor improvement. By using additional non-linear terms in the stress-strain coupling relationship, created by the evolutionary algorithm, the near-wake can also be improved upon. Terms created by the algorithm are scrutinized and the discussion is closed by suggesting a tentative non-linear expression for the Reynolds stress, suitable for the wake behind a high-pressure turbine blade.

Influence of Different Parametrizations on the Optimum Design of a High Pressure Turbine Blade Firtree

2016 ◽  
Author(s):  
Frank Wagner ◽  
Arnold Kühhorn ◽  
Thomas Weiss ◽  
Dierk Otto
Keyword(s):  
High Pressure ◽  
Turbine Blade ◽  
Complex Geometry ◽  
Three Dimensional ◽  
Parametric Models ◽  
Limiting Factor ◽  
High Pressure Turbine ◽  
The Creation ◽  
High Flexibility ◽  
Critical Regions

Today the design processes in the aero industry face many challenges. Apart from automation itself, a suitable parametric geometry setup plays a significant role in making workflows usable for optimization. At the same time there are tough requirements against the parametric model. For the lowest number of possible parameters, which should be intuitively ascertainable, a high flexibility has to be ensured. Within the parameter range an acceptable stability is necessary. Under these constraints the creation of such parametric models is a challenge, which should not be underestimated especially for a complex geometry. In this work different kinds of parametrization with different levels of complexity will be introduced and compared. Thereby several geometry elements will be used to handle the critical regions of the geometry. In the simplest case a combination of lines and arcs will be applied. These will be replaced by superior elements like a double arc construct or different formulations of b-splines. There will be an additional focus on the variation of spline degree and control points. To guarantee consistency a set of general parameters will be used next to the specific ones at the critical regions. The different parameter boundaries have a influence on the possible geometries and should therefore be tested separately before an optimization run. The analysis of the particular parametrization should be compared against the following points: • effort for the creation of the parametrization in theory • required time for the implementation in the CAD software • error-proneness/robustness of the parametrization • flexibility of the possible geometries • accuracy of the results • influence of the number of runs on the optimization • comparison of the best results Even though this assessment matrix is only valid for the considered case, it should show the general trend for the creation of these kinds of parametric models. This case takes a look at a firtree of a high pressure turbine blade, which is a scaled version of the first row from a small to medium aero engine. The failure of such a component can lead to a critical engine failure. For that reason, the modeling/meshing must be done very carefully and the contact between the blade and the disc is of crucial importance. It is possible to use scaling factors for three dimensional effects to reduce the problem to a two dimensional problem. Therefore the contact description is shortened from face-to-line to line-to-point. The main aim of the optimization is the minimization of the tension (notch stress) at the inner bends of the blade respectively at the outer bends of the disc. This has been the limiting factor in previous investigations. At this part of the geometry the biggest improvement are expected from a superior parametrization. Another important constraint in the optimization is the pressure contact (crushing stress) between blade and disc. Additionally the geometry is restricted with measurements of the lowest diameter at specific fillets to fulfill manufacturing requirements.

Modeling and Impact of High-pressure Turbine Blade Trailing Edge Film Cooling Hole Variations

2020 ◽  
Author(s):  
Jan Kamenik ◽  
David J. Toal ◽  
Andy Keane ◽  
Lars Högner ◽  
Marcus Meyer ◽  
...  
Keyword(s):  
High Pressure ◽  
Turbine Blade ◽  
Film Cooling ◽  
High Pressure Turbine ◽  
Trailing Edge ◽  
Cooling Hole

Using CFD to Reduce Resonant Stresses on a Single-Stage, High-Pressure Turbine Blade

2002 ◽  
Author(s):  
J. P. Clark ◽  
A. S. Aggarwala ◽  
M. A. Velonis ◽  
R. E. Gacek ◽  
S. S. Magge ◽  
...  
Keyword(s):  
High Pressure ◽  
Turbine Blade ◽  
Guide Vane ◽  
Turbine Blades ◽  
Suction Side ◽  
Lessons Learned ◽  
Single Stage ◽  
Navier Stokes ◽  
High Pressure Turbine ◽  
Time Resolved

The ability to predict levels of unsteady forcing on high-pressure turbine blades is critical to avoid high-cycle fatigue failures. In this study, 3D time-resolved computational fluid dynamics is used within the design cycle to predict accurately the levels of unsteady forcing on a single-stage high-pressure turbine blade. Further, nozzle-guide-vane geometry changes including asymmetric circumferential spacing and suction-side modification are considered and rigorously analyzed to reduce levels of unsteady blade forcing. The latter is ultimately implemented in a development engine, and it is shown successfully to reduce resonant stresses on the blade. This investigation builds upon data that was recently obtained in a full-scale, transonic turbine rig to validate a Reynolds-Averaged Navier-Stokes (RANS) flow solver for the prediction of both the magnitude and phase of unsteady forcing in a single-stage HPT and the lessons learned in that study.

scholarly journals Erratum to: Dynamic probabilistic design approach of high-pressure turbine blade-tip radial running clearance

2016 ◽  
Vol 86 (1) ◽  
pp. 225-225
Author(s):  
Cheng-Wei Fei ◽  
Yat-Sze Choy ◽  
Dian-Yin Hu ◽  
Guang-Chen Bai ◽  
Wen-Zhong Tang
Keyword(s):  
High Pressure ◽  
Turbine Blade ◽  
Design Approach ◽  
Probabilistic Design ◽  
High Pressure Turbine ◽  
Blade Tip

Time-Averaged and Time-Accurate Aero-Dynamics for the Recessed Tip Cavity of a High-Pressure Turbine Blade and the Outer Stationary Shroud: Comparison of Computational and Experimental Results

2004 ◽  
Author(s):  
Brian R. Green ◽  
John W. Barter ◽  
Charles W. Haldeman ◽  
Michael G. Dunn
Keyword(s):  
High Pressure ◽  
Turbine Blade ◽  
Computational Models ◽  
Turbine Rotor ◽  
Single Stage ◽  
Cfd Modeling ◽  
Blade Surface ◽  
High Pressure Turbine ◽  
Pressure Transducers ◽  
Blade Tip

The unsteady aero-dynamics of a single-stage high-pressure turbine blade operating at design corrected conditions has been the subject of a thorough study involving detailed measurements and computations. The experimental configuration consisted of a single-stage high-pressure turbine and the adjacent, downstream, low-pressure turbine nozzle row. All three blade-rows were instrumented at three spanwise locations with flush-mounted, high frequency response pressure transducers. The rotor was also instrumented with the same transducers on the blade tip and platform and the stationary shroud was instrumented with pressure transducers at specific locations above the rotating blade. Predictions of the time-dependent flow field around the rotor were obtained using MSU-TURBO, a 3D, non-linear, computational fluid dynamics (CFD) code. Using an isolated blade-row unsteady analysis method, the unsteady surface pressure for the high-pressure turbine rotor due to the upstream high-pressure turbine nozzle was calculated. The predicted unsteady pressure on the rotor surface was compared to the measurements at selected spanwise locations on the blade, in the recessed cavity, and on the shroud. The rig and computational models included a flat and recessed blade tip geometry and were used for the comparisons presented in the paper. Comparisons of the measured and predicted static pressure loading on the blade surface show excellent correlation from both a time-average and time-accurate standpoint. This paper concentrates on the tip and shroud comparisons between the experiments and the predictions and these results also show good correlation with the time-resolved data. These data comparisons provide confidence in the CFD modeling and its ability to capture unsteady flow physics on the blade surface, in the flat and recessed tip regions of the blade, and on the stationary shroud.

Morphology of γ' Precipitates in Second Stage High Pressure Turbine Blade of Single Crystal Nickel-Based Superalloy after Serviced

2010 ◽  
Vol 638-642 ◽  
pp. 2291-2296 ◽  
Author(s):  
N. Miura ◽  
K. Nakata ◽  
M. Miyazaki ◽  
Y. Hayashi ◽  
Y. Kondo
Keyword(s):  
High Pressure ◽  
Single Crystal ◽  
Turbine Blade ◽  
Leading Edge ◽  
Aircraft Engine ◽  
Pressure Side ◽  
High Pressure Turbine ◽  
Second Stage ◽  
Nickel Based Superalloy ◽  
The Matrix

The morphology of the ’ precipitates in the single crystal nickel-based superalloy serviced as the second stage high pressure turbine blade of the aircraft engine was examined. The aim of this work was to estimate the temperature and the stress distribution, and the stress direction of the blade in service. The blade was cut into three parts parallel to (001) plane at 8, 40 and 64mm from the tip. These parts were named as the tip, middle and root parts. Furthermore, these three parts were cut into six parts parallel to {100} which were almost normal to the surface from the leading to the trailing edge at interval of 6mm. Microstructure observations by a FE-SEM were carried out on the thirty portions of each part parallel to (001) and {100} planes at the vicinity of the interface between the coating layer and the matrix in the suction and pressure sides. Most of the ’ precipitates contacted each other toward almost parallel to the surface at the vicinity of the interface in the blade. Especially, at the leading edge of the pressure side of the tip and middle parts, the rafted /’ structures start to collapse. Consequently, the blade in service, at the leading edge of the pressure side of the tip and middle parts were exposed to the highest temperature and stress conditions. And the multi-axial compressive stresses parallel to the blade surface were expected to act on the blade in service.

Numerical investigation of high-pressure turbine blade tip flows: analysis of aerodynamics

2011 ◽  
Vol 225 (7) ◽  
pp. 940-953 ◽  
Author(s):  
P Vass ◽  
T Arts
Keyword(s):  
High Pressure ◽  
Turbine Blade ◽  
Three Dimensional ◽  
Suction Side ◽  
Point Of View ◽  
Internal Cooling ◽  
High Pressure Turbine ◽  
Blade Tip ◽  
Design Solutions ◽  
Exit Mach Number

The current contribution reports on the validation and analysis of three-dimensional computational results of the flow around four distinct high-pressure turbine blade tip geometries (TG1, 2, 3, and 4 hereinafter), taking into account the effect of the entire internal cooling setup inside the blade, at design exit Mach number: M = 0.8, and high exit Reynolds number: Re C = 900 000. Three of the four geometries represent different tip design solutions – TG1: full squealer rim; TG2: single squealer on the suction side; TG3: partial suction and pressure side squealer, and one (TG4) models TG1 in worn condition. This article provides a comparison between the different geometries from the aerodynamic point of view, analyses the losses, and evaluates the distinct design solutions. An assessment of the effect of the uneven rubbing of the blade tip was performed as well. TG1 was found to be the top performer followed by TG3 and TG2. According to the investigations, the effect of rubbing increased the kinetic loss coefficient by 10–15 per cent.

Sign in / Sign up

Export Citation Format

Share Document