Design of the Purdue Experimental Turbine Aerothermal Laboratory for Optical and Surface Aero-Thermal Measurements

Following three decades of research in short duration facilities, Purdue University has developed an alternative turbine facility in view of the modern technology in computational fluid mechanics, structural analysis, manufacturing, heating, control and electronics. The proposed turbine facility can perform both short transients and long duration tests, suited for precise heat flux, efficiency and optical measurement techniques to advance turbine aero-thermo-structural engineering. The facility has two different test sections, linear and annular, to service both fundamental and applied research. The linear test section is completely transparent for visible spectra, aimed at TRL 1 and 2. The annular test section was designed with optical access to perform proof of concepts as well as validation of turbine components at the relevant non-dimensional parameters in small engine cores, TRL 3 to 4. The large mass flow (28 kg/s) combined with a minimum hub radius to tip radius of 0.85 allows high spatial resolution. The Reynolds (Re) number extends from 60,000 to 3,000,000, based on the vane outlet flow with an axial chord of 0.06 m and a turning angle of 72 deg. The pressure ratio can be independently adjusted, allowing for testing from low subsonic to Mach 3.2. To ensure that the thermal boundary layer is fully developed the test duration can range from milliseconds to minutes. The manuscript provides a detailed description of the sequential design methodology from zero-dimensional to three-dimensional unsteady analysis as well as of the measurement techniques available in this turbine facility.

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Design of the Purdue Experimental Turbine Aerothermal Laboratory for Optical and Surface Aerothermal Measurements

Journal of Engineering for Gas Turbines and Power ◽

10.1115/1.4040683 ◽

2018 ◽

Vol 141 (1) ◽

Cited By ~ 3

Author(s):

G. Paniagua ◽

D. Cuadrado ◽

J. Saavedra ◽

V. Andreoli ◽

T. Meyer ◽

...

Keyword(s):

Test Section ◽

Structural Engineering ◽

Optical Measurement ◽

Pressure Ratio ◽

Measurement Techniques ◽

Three Dimensional ◽

Large Mass ◽

Modern Technology ◽

Computational Fluid Mechanics ◽

Imaging And Spectroscopy

Following three decades of research in short duration facilities, Purdue University has developed an alternative turbine facility in view of the modern technology in computational fluid mechanics, structural analysis, manufacturing, heating, control, and electronics. The proposed turbine facility can operate continuously and also perform transients, suited for precise heat flux, efficiency, and optical measurement techniques to advance turbine aerothermo-structural engineering. The facility has two different test sections, linear and annular, to service both fundamental and applied research. The linear test section is completely transparent for optical imaging and spectroscopy, aimed at technology readiness levels (TRLs) of 1–2. The annular test section was designed with optical access to perform proof of concepts as well as validation of turbine component performance for relevant nondimensional parameters at TRLs of 3–4. The large mass flow rate (28 kg/s) combined with a minimum hub to tip ratio of 0.85 allows high spatial resolution. The Reynolds number (Re) extends from 60,000 to 3,000,000, based on the vane outlet flow properties with an axial chord of 0.06 m and a turning angle of 72 deg. The pressure ratio can be independently adjusted, enabling testing from low subsonic to Mach 3.2. This paper provides a detailed description of the sequential design methodology from zero-dimensional to three-dimensional (3D) unsteady analysis as well as of the measurement techniques available in this turbine facility.

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Vortex Tracking of Purge-Mainstream Interactions in a Rotating Turbine Stage

10.1115/gt2021-59701 ◽

2021 ◽

Author(s):

Alex W. Mesny ◽

Mark A. Glozier ◽

Oliver J. Pountney ◽

James A. Scobie ◽

Yan Sheng Li ◽

...

Keyword(s):

Secondary Flow ◽

Gas Turbines ◽

Optical Measurement ◽

Measurement Techniques ◽

Three Dimensional ◽

Horseshoe Vortex ◽

Suction Surface ◽

Vortex Filaments ◽

Passage Vortex ◽

Purge Flow

Abstract The use of purge flow in gas turbines allows for high turbine entry temperatures, which are essential to produce high cycle efficiency. Purge air is bled from the compressor and reintroduced in the turbine to cool vulnerable components. Wheel-spaces are formed between adjacent rotating and stationary discs, with purge air supplied at low radius before exiting into the mainstream gas-path through a rim-seal at the disc periphery. An aerodynamic penalty is incurred as the purge flow egress interacts with the mainstream. This study presents unparalleled three-dimensional velocity data from a single-stage turbine test rig, specifically designed to investigate egress-mainstream interaction using optical measurement techniques. Volumetric Velocimetry is applied to the rotating environment with phase-locked measurements used to identify and track the vortical secondary flow features through the blade passage. A baseline case without purge flow is compared to experiments with a 1.7% purge mass fraction; the latter was chosen to ensure a fully sealed wheel-space. A non-localised vortex tracking function is applied to the data to identify the position of the core centroids. The strength of the secondary-flow vortices was determined by using a circulation criterion on rotated planes aligned to the vortex filaments. The pressure-side leg of the horseshoe vortex and a second vortex associated with the egress flow were identified by the experimental campaign. In the absence of purge flow the two vortices merged, forming the passage vortex. With the addition of purge flow, the two cores remained independent to 40% of the blade axial chord, while also demonstrating an increased radial migration and intensification of the passage vortex. The egress core was shown to remain closer to the suction-surface with purge flow. Importantly, where the vortex filaments demonstrated strong radial or tangential components of velocity, the circulation level calculated from axial planes underpredicted the true circulation by up to 50%.

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Near-Wall Stereo PIV Investigation of the Turbulent Channel Flow Over Rough-Walls

Volume 1: Symposia, Parts A and B ◽

10.1115/fedsm2008-55197 ◽

2008 ◽

Author(s):

Jiarong Hong ◽

Joseph Katz ◽

Michael Schultz

Keyword(s):

Channel Flow ◽

Optical Measurement ◽

Measurement Techniques ◽

Three Dimensional ◽

Turbulent Channel Flow ◽

Mean Velocity ◽

Roughness Elements ◽

Sample Data ◽

Near Wall

The near-wall turbulent flow in the rough-wall channel is of great significance in engineering applications, but remains a challenge for both experimental measurement and numerical modeling due to the complexity of the roughness geometry. For optical measurement techniques, e.g. PIV, obstruction by the roughness elements and reflection from the surface adversely affect the quality of near wall data. Our present study utilizes a facility containing a fluid with the same refractive index as the rough acrylic wall, making the interface almost invisible, and employs Stereo PIV to obtain the three-dimensional flow field in the vicinity of the roughness elements. The roughness shape is a uniformly distributed and closely packed, 0.5 mm high pyramid, corresponding to 95 wall units, with a pitch angle of 22.5 degrees. The length of the rough surface is sufficiently long to obtain self-similar roughness boundary layer, turbulent channel flow at a mean velocity of 3.8 m/s, with a clearly defined log layer. Results will include sample data of the complete flow, both around and above the roughness elements. Issues related to implementation of Stereo PIV in an index-matched facility will be discussed.

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VORTEX TRACKING OF PURGE-MAINSTREAM INTERACTIONS IN A ROTATING TURBINE STAGE

Journal of Turbomachinery ◽

10.1115/1.4052690 ◽

2021 ◽

pp. 1-22

Author(s):

Alex Mesny ◽

Mark Glozier ◽

Oliver J Pountney ◽

James Scobie ◽

Yansheng Li ◽

...

Keyword(s):

Secondary Flow ◽

Gas Turbines ◽

Optical Measurement ◽

Measurement Techniques ◽

Three Dimensional ◽

Turbine Stage ◽

Baseline Case ◽

Flow Features ◽

Purge Flow ◽

Cycle Efficiency

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Comparison of Two Methods for Sensitivity Analysis of Compressor Blades

Journal of Turbomachinery ◽

10.1115/1.4037127 ◽

2017 ◽

Vol 139 (11) ◽

Author(s):

Robin Schmidt ◽

Matthias Voigt ◽

Konrad Vogeler ◽

Marcus Meyer

Keyword(s):

Sensitivity Analysis ◽

Monte Carlo ◽

Polynomial Regression ◽

Optical Measurement ◽

Measurement Techniques ◽

Three Dimensional ◽

Sampling Strategy ◽

Initial Flow ◽

Efficient Sampling ◽

The Impact

This paper will compare two approaches of sensitivity analysis, namely (i) the adjoint method which is used to obtain an initial estimate of the geometric sensitivity of the gas-washed surfaces to aerodynamic quantities of interest and (ii) a Monte Carlo type simulation with an efficient sampling strategy. For both approaches, the geometry is parameterized using a modified NACA parameterization. First, the sensitivity of those parameters is calculated using the linear (first-order) adjoint model. Since the effort of the adjoint computational fluid dynamics (CFD) solution is comparable to that of the initial flow CFD solution and the sensitivity calculation is simply a postprocessing step, this approach yields fast results. However, it relies on a linear model which may not be adequate to describe the relationship between relevant aerodynamic quantities and actual geometric shape variations for the derived amplitudes of shape variations. Second, in order to better capture nonlinear and interaction effects, a Monte Carlo type simulation with an efficient sampling strategy is used to carry out the sensitivity analysis. The sensitivities are expressed by means of the coefficient of importance (CoI), which is calculated based on modified polynomial regression and therefore able to describe relationships of higher order. The methods are applied to a typical high-pressure compressor (HPC) stage. The impact of a variable rotor geometry is calculated by three-dimensional (3D) CFD simulations using a steady Reynolds-averaged Navier–Stokes model. The geometric variability of the rotor is based on the analysis of a set of 400 blades which have been measured using high-precision 3D optical measurement techniques.

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Optical Measurement Techniques Using Laser Diodes (Part 2)

Measurement and Control ◽

10.1177/002029408301601203 ◽

1983 ◽

Vol 16 (12) ◽

pp. 468-470

Author(s):

Malcolm Fabian

Keyword(s):

Optical Measurement ◽

Measurement Techniques ◽

Laser Diodes

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On the forces that cable webs under tension can support and how to design cable webs to channel stresses

Proceedings of The Royal Society A Mathematical Physical and Engineering Sciences ◽

10.1098/rspa.2018.0781 ◽

2019 ◽

Vol 475 (2223) ◽

pp. 20180781 ◽

Cited By ~ 5

Author(s):

Guy Bouchitté ◽

Ornella Mattei ◽

Graeme W. Milton ◽

Pierre Seppecher

Keyword(s):

Linear Programming ◽

Convex Hull ◽

Structural Engineering ◽

Three Dimensional ◽

Two Dimensions ◽

Three Dimensions ◽

Sufficient Condition ◽

Necessary And Sufficient Condition ◽

Finite Dimensional ◽

Necessary And Sufficient

In many applications of structural engineering, the following question arises: given a set of forces f 1 , f 2 , …, f N applied at prescribed points x 1 , x 2 , …, x N , under what constraints on the forces does there exist a truss structure (or wire web) with all elements under tension that supports these forces? Here we provide answer to such a question for any configuration of the terminal points x 1 , x 2 , …, x N in the two- and three-dimensional cases. Specifically, the existence of a web is guaranteed by a necessary and sufficient condition on the loading which corresponds to a finite dimensional linear programming problem. In two dimensions, we show that any such web can be replaced by one in which there are at most P elementary loops, where elementary means that the loop cannot be subdivided into subloops, and where P is the number of forces f 1 , f 2 , …, f N applied at points strictly within the convex hull of x 1 , x 2 , …, x N . In three dimensions, we show that, by slightly perturbing f 1 , f 2 , …, f N , there exists a uniloadable web supporting this loading. Uniloadable means it supports this loading and all positive multiples of it, but not any other loading. Uniloadable webs provide a mechanism for channelling stress in desired ways.

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Robotic motion compensation for bone movement, using ultrasound images

Industrial Robot the international journal of robotics research and application ◽

10.1108/ir-12-2014-0435 ◽

2015 ◽

Vol 42 (5) ◽

pp. 466-474 ◽

Cited By ~ 4

Author(s):

P.M.B. Torres ◽

P. J. S. Gonçalves ◽

J.M.M. Martins

Keyword(s):

Motion Compensation ◽

Optical Measurement ◽

Three Dimensional ◽

Point Clouds ◽

Robotic System ◽

Ultrasound Images ◽

Bone Drilling ◽

Content Type ◽

3D Point Clouds ◽

Robotic Motion

Purpose – The purpose of this paper is to present a robotic motion compensation system, using ultrasound images, to assist orthopedic surgery. The robotic system can compensate for femur movements during bone drilling procedures. Although it may have other applications, the system was thought to be used in hip resurfacing (HR) prosthesis surgery to implant the initial guide tool. The system requires no fiducial markers implanted in the patient, by using only non-invasive ultrasound images. Design/methodology/approach – The femur location in the operating room is obtained by processing ultrasound (USA) and computer tomography (CT) images, obtained, respectively, in the intra-operative and pre-operative scenarios. During surgery, the bone position and orientation is obtained by registration of USA and CT three-dimensional (3D) point clouds, using an optical measurement system and also passive markers attached to the USA probe and to the drill. The system description, image processing, calibration procedures and results with simulated and real experiments are presented and described to illustrate the system in operation. Findings – The robotic system can compensate for femur movements, during bone drilling procedures. In most experiments, the update was always validated, with errors of 2 mm/4°. Originality/value – The navigation system is based entirely on the information extracted from images obtained from CT pre-operatively and USA intra-operatively. Contrary to current surgical systems, it does not use any type of implant in the bone to track the femur movements.

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Automatic Three-Dimensional Optimisation of a Modern Tandem Compressor Vane

Volume 2B: Turbomachinery ◽

10.1115/gt2014-26762 ◽

2014 ◽

Cited By ~ 3

Author(s):

R. C. Schlaps ◽

S. Shahpar ◽

V. Gümmer

Keyword(s):

Pressure Ratio ◽

Three Dimensional ◽

Trust Region ◽

Automatic Generation ◽

Navier Stokes ◽

Design Parameters ◽

High Fidelity ◽

Stall Margin ◽

Design Choice ◽

Multipoint Approximation

In order to increase the performance of a modern gas turbine, compressors are required to provide higher pressure ratio and avoid incurring higher losses. The tandem aerofoil has the potential to achieve a higher blade loading in combination with lower losses compared to single vanes. The main reason for this is due to the fact that a new boundary layer is generated on the second blade surface and the turning can be achieved with smaller separation occurring. The lift split between the two vanes with respect to the overall turning is an important design choice. In this paper an automated three-dimensional optimisation of a highly loaded compressor stator is presented. For optimisation a novel methodology based on the Multipoint Approximation Method (MAM) is used. MAM makes use of an automatic design of experiments, response surface modelling and a trust region to represent the design space. The CFD solutions are obtained with the high-fidelity 3D Navier-Stokes solver HYDRA. In order to increase the stage performance the 3D shape of the tandem vane is modified changing both the front and rear aerofoils. Moreover the relative location of the two aerofoils is controlled modifying the axial and tangential relative positions. It is shown that the novel optimisation methodology is able to cope with a large number of design parameters and produce designs which performs better than its single vane counterpart in terms of efficiency and numerical stall margin. One of the key challenges in producing an automatic optimisation process has been the automatic generation of high-fidelity computational meshes. The multi block-structured, high-fidelity meshing tool PADRAM is enhanced to cope with the tandem blade topologies. The wakes of each aerofoil is properly resolved and the interaction and the mixing of the front aerofoil wake and the second tandem vane are adequately resolved.

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