Five-Hole Probes (FHP), being a dependable and accurate aerodynamic tool, are an excellent choice for measuring three-dimensional flow fields in turbomachinery. To improve spatial resolution, a subminiature FHP with a diameter of 1.68&#x2009;mm is employed. High length to diameter ratio of the tubing and manual pitch and yaw calibration cause increased uncertainty. A new FHP calibrator is designed and built to reduce the uncertainty by precise, computer controlled movements and reduced calibration time. The calibrated FHP is then placed downstream of the nozzle guide vane (NGV) assembly of a low-speed, large-scale, axial flow turbine. The cold flow HP turbine stage contains 29 vanes and 36 blades. A fast and computer controllable traversing system is implemented using an adaptive grid method for the refinement of measurements in regions such as vane wake, secondary flows, and boundary layers. The current approach increases the possible number of measurement points in a two-hour period by 160&#x25;. Flow structures behind the NGV measurement plane are identified with high spatial resolution and reduced uncertainty. The automated pitch and yaw calibration and the adaptive grid approach introduced in this study are shown to be a highly effective way of measuring complex flow fields in the research turbine.

Jason Town

Cengiz Camci

A Time Efficient Adaptive Gridding Approach and Improved Calibrations in Five-Hole Probe Measurements

Blade row interactions in turbomachinery can lead to blade vibrations and even high cycle fatigue. Forced response conditions occur when a forcing function (such as impingement of stator wakes) occurs at a frequency that matches the natural frequency of a blade. The objective of this research is to develop the data processing techniques needed to detect rotor blade vibration in a forced response condition from stationary fast-response pressure transducers to allow for detection of rotor vibration from transient data and lead to techniques for vibration monitoring in gas turbines. This paper marks the first time in the open literature that engine-order resonant response of an embedded bladed disk in a 3-stage intermediate-speed axial compressor was detected using stationary pressure transducers. Experiments were performed in a stage axial research compressor focusing on the embedded rotor of blisk construction. Fourier waterfall graphs from a laser tip timing system were used to detect the vibrations after applying signal processing methods to uncover these pressure waves associated with blade vibration. Individual blade response was investigated using cross covariance to compare blade passage pressure signatures through resonance. Both methods agree with NSMS data that provide a measure of the exact compressor speeds at which individual blades enter resonance.

William L. Murray

Nicole L. Key

Detection of Rotor Forced Response Vibrations Using Stationary Pressure Transducers in a Multistage Axial Compressor

A computational and experimental study is carried out on the leading edge region of a typical gas turbine NGV, cooled by a combination of impingement and showerhead film cooling. A detailed flow and conjugate heat transfer study has revealed the complex flow structure owing to the coolant-mainstream interaction and the influence of vane material thermal conductivity. The local effectiveness values obtained by the computations agreed well with the experimental data from IR thermography. The effect of blowing ratio on the overall effectiveness is found to be strongly dependent on the vane material conductivity. The effect of blowing ratio is also found to be different towards the pressure and suction sides of the stagnation region. However, the overall effectiveness is found to decrease by about 12&#x25; and 6&#x25; for low and high conducting materials, respectively, with an increase in mainstream Reynolds number from <svg xmlns:xlink="http://www.w3.org/1999/xlink" xmlns="http://www.w3.org/2000/svg" style="vertical-align:-0.3629999pt" id="M1" height="11.9296pt" version="1.1" viewBox="-0.0498162 -11.5666 76.4226 11.9296" width="76.4226pt"><g transform="matrix(.013,0,0,-0.013,0,0)"><path id="g190-83" d="M631 18C609 24 585 35 559 65C534 91 514 117 478 169C448 214 406 281 389 313C462 346 516 399 516 485C516 545 490 590 449 616C412 641 363 650 290 650H42V622C120 615 128 612 128 527V125C128 40 120 34 38 28V0H300V28C221 34 212 40 212 125V284H244C295 284 312 272 329 244C359 195 395 133 430 84C475 19 516 -3 592 -7C603 -8 615 -8 627 -8L631 18ZM212 316V563C212 591 215 602 223 607C231 613 248 617 277 617C352 617 423 577 423 469C423 415 407 375 368 345C343 324 310 316 260 316H212Z"/></g><g transform="matrix(.013,0,0,-0.013,8.112,0)"><path id="g190-102" d="M380 106C343 72 306 56 265 56C195 56 116 112 115 248C235 252 361 262 377 265C396 269 400 277 400 297C400 374 333 449 250 449H249C198 449 144 421 103 376S37 269 37 201C37 88 109 -12 232 -12C263 -12 332 6 395 84L380 106ZM225 412C281 412 315 364 314 312C314 297 308 292 290 292C232 290 176 289 120 289C135 370 180 412 225 412Z"/></g><g transform="matrix(.013,0,0,-0.013,17.364,0)"><path id="g54-34" d="M556 331V384H55V331H556ZM556 140V193H55V140H556Z"/></g><g transform="matrix(.013,0,0,-0.013,28.982,0)"><path id="g50-53" d="M462 177V227H365V632H320C217 496 116 350 21 208V177H284V109C284 43 280 38 190 31V0H451V31C369 38 365 43 365 108V177H462ZM284 227H88C155 336 218 430 282 519H284V227Z"/></g><g transform="matrix(.013,0,0,-0.013,35.313,0)"><path id="g50-47" d="M117 -12C153 -12 178 12 178 50C178 84 153 110 118 110C84 110 59 84 59 50C59 12 84 -12 117 -12Z"/></g><g transform="matrix(.013,0,0,-0.013,38.394,0)"><path id="g50-57" d="M253 635C142 635 71 555 71 471C71 401 113 353 178 316C144 294 106 267 91 252C70 231 46 202 46 157C46 51 132 -12 241 -12C328 -12 442 52 442 168C442 257 379 305 311 343C354 373 380 398 388 407C406 428 417 458 417 487C417 568 348 635 253 635ZM240 600C288 600 340 563 340 481C340 423 313 387 279 360C207 394 148 427 148 499C148 549 182 600 240 600ZM252 23C188 23 129 73 129 163C129 217 162 266 211 298C289 260 360 217 360 144C360 69 312 23 252 23Z"/></g><g transform="matrix(.013,0,0,-0.013,47.665,0)"><path id="g54-42" d="M547 55L345 261L547 468L508 508L306 301L104 508L65 468L267 261L65 55L104 14L306 221L508 14L547 55Z"/></g><g transform="matrix(.013,0,0,-0.013,58.549,0)"><path id="g50-50" d="M389 0V32C297 38 291 46 291 118V635C234 613 175 595 109 583V556L161 554C203 552 207 547 207 497V118C207 46 201 38 110 32V0H389Z"/></g><g transform="matrix(.013,0,0,-0.013,64.88,0)"><path id="g50-49" d="M245 635C92 635 37 457 37 312C37 149 91 -12 244 -12C395 -12 449 166 449 312C449 469 395 635 245 635ZM243 598C332 598 358 454 358 312C358 173 334 26 245 26C158 26 128 174 128 313S152 598 243 598Z"/></g><g transform="matrix(.0091,0,0,-0.0091,71.258,-5.872)"><path id="g50-54" d="M158 548H390L417 615L410 623H122L83 318C105 326 143 337 185 337C296 337 350 275 350 188C350 116 308 42 225 42C164 42 122 74 100 93C90 101 82 99 72 92C60 82 51 68 50 59C48 46 52 38 66 24C82 9 125 -12 172 -12C225 -11 292 15 346 59C408 108 437 166 437 226C437 309 371 397 242 397C214 397 170 382 133 369L158 548Z"/></g></svg> to <svg xmlns:xlink="http://www.w3.org/1999/xlink" xmlns="http://www.w3.org/2000/svg" style="vertical-align:-0.3629999pt" id="M2" height="11.9296pt" version="1.1" viewBox="-0.0498162 -11.5666 53.7657 11.9296" width="53.7657pt"><g transform="matrix(.013,0,0,-0.013,0,0)"><use xlink:href="#g50-50"/></g><g transform="matrix(.013,0,0,-0.013,6.331,0)"><use xlink:href="#g50-53"/></g><g transform="matrix(.013,0,0,-0.013,12.662,0)"><use xlink:href="#g50-47"/></g><g transform="matrix(.013,0,0,-0.013,15.743,0)"><use xlink:href="#g50-53"/></g><g transform="matrix(.013,0,0,-0.013,25.015,0)"><use xlink:href="#g54-42"/></g><g transform="matrix(.013,0,0,-0.013,35.898,0)"><use xlink:href="#g50-50"/></g><g transform="matrix(.013,0,0,-0.013,42.229,0)"><use xlink:href="#g50-49"/></g><g transform="matrix(.0091,0,0,-0.0091,48.608,-5.872)"><use xlink:href="#g50-54"/></g></svg>.

Dileep Chandran

Bhamidi Prasad

Conjugate Heat Transfer Study of Combined Impingement and Showerhead Film Cooling Near NGV Leading Edge

An analysis of compressor rotor tip clearance measurements using capacitance probe instrumentation is discussed for a three-stage axial compressor. Thermal variations and centrifugal effects related to rotational speed changes affect clearance heights relative to the assembled configuration. These two primary contributions to measured changes are discussed both independently and in combination. Emphasis is given to tip clearance changes due to changing loading condition and at several compressor operating speeds. Measurements show a tip clearance change approaching 0.1&#x2009;mm (0.2&#x25; rotor span) when comparing a near-choke operating condition to a near-stall operating condition for the third stage. Additional consideration is given to environmental contributions such as ambient temperature, for which changes in tip clearance height on the order of 0.05&#x2009;mm (0.1&#x25; rotor span) were noted for temperature variations of 15&#xb0;C. Experimental compressor operating clearances are presented for several temperatures, operating speeds, and loading conditions, and comparisons are drawn between these measured variations and predicted changes under the same conditions.

Reid A. Berdanier

Experimental Investigation of Factors Influencing Operating Rotor Tip Clearance in Multistage Compressors

This paper reviews some experimental measurements of convective heat transfer coefficient distributions which are connected with the cooling of gas turbines, performed by the authors&#x2019; research group at the University of Naples Federico II with infrared thermography. Measurements concern impinging jets, cooling of rotating disks, and gas turbine blades, which are either stationary or rotating. The heated thin foil sensor, associated with the detection of surface temperature by means of infrared thermography, is exploited to accurately measure detailed convective heat transfer coefficient maps. The paper also intends to show how to correctly apply the infrared technique in a variety of gas turbines cooling problems.

T. Astarita

G. Cardone

L. de Luca

G. M. Carlomagno

Some Experimental Investigations on Gas Turbine Cooling Performed with Infrared Thermography at Federico II

Incompressible large eddy simulation and direct numerical simulation of a low-pressure turbine at <svg xmlns:xlink="http://www.w3.org/1999/xlink" xmlns="http://www.w3.org/2000/svg" style="vertical-align:-0.3625994pt" id="M1" height="12.4407pt" version="1.1" viewBox="-0.0498162 -12.0781 84.7875 12.4407" width="84.7875pt"><g transform="matrix(.0135,0,0,-0.0135,0,0)"><path id="g190-83" d="M631 18C609 24 585 35 559 65C534 91 514 117 478 169C448 214 406 281 389 313C462 346 516 399 516 485C516 545 490 590 449 616C412 641 363 650 290 650H42V622C120 615 128 612 128 527V125C128 40 120 34 38 28V0H300V28C221 34 212 40 212 125V284H244C295 284 312 272 329 244C359 195 395 133 430 84C475 19 516 -3 592 -7C603 -8 615 -8 627 -8L631 18ZM212 316V563C212 591 215 602 223 607C231 613 248 617 277 617C352 617 423 577 423 469C423 415 407 375 368 345C343 324 310 316 260 316H212Z"/></g><g transform="matrix(.0135,0,0,-0.0135,8.445,0)"><path id="g190-102" d="M380 106C343 72 306 56 265 56C195 56 116 112 115 248C235 252 361 262 377 265C396 269 400 277 400 297C400 374 333 449 250 449H249C198 449 144 421 103 376S37 269 37 201C37 88 109 -12 232 -12C263 -12 332 6 395 84L380 106ZM225 412C281 412 315 364 314 312C314 297 308 292 290 292C232 290 176 289 120 289C135 370 180 412 225 412Z"/></g><g transform="matrix(.0135,0,0,-0.0135,18.01,0)"><path id="g117-34" d="M535 323V373H52V323H535ZM535 138V188H52V138H535Z"/></g><g transform="matrix(.0135,0,0,-0.0135,29.747,0)"><path id="g113-54" d="M153 550H386L412 615L406 623H120L82 318C104 327 142 338 184 338C294 338 347 275 347 187C347 112 305 39 221 39C160 39 119 71 97 89C88 97 80 96 71 90C59 80 50 67 49 57C48 45 52 36 66 23C80 9 123 -12 169 -12C221 -11 288 15 342 59C403 109 431 165 431 225C431 308 366 395 238 395C212 395 165 379 127 364L153 550Z"/></g><g transform="matrix(.0135,0,0,-0.0135,36.251,0)"><path id="g113-47" d="M113 -12C146 -12 170 11 170 46C170 78 146 103 114 103S58 78 58 46C58 11 82 -12 113 -12Z"/></g><g transform="matrix(.0135,0,0,-0.0135,39.34,0)"><path id="g113-50" d="M384 0V27C293 34 287 42 287 114V635C232 613 172 594 109 583V559L157 557C201 555 205 550 205 499V114C205 42 199 34 109 27V0H384Z"/></g><g transform="matrix(.0135,0,0,-0.0135,45.843,0)"><path id="g113-57" d="M249 635C141 635 70 555 70 471C70 401 114 353 179 316C143 294 106 267 90 252C68 231 45 202 45 157C45 50 130 -12 237 -12C322 -12 435 52 435 169C435 256 372 304 303 343C349 374 375 398 383 407C401 429 411 458 411 487C411 569 344 635 249 635ZM238 603C285 603 337 567 337 482C337 422 310 385 276 358C205 393 145 426 145 500C145 552 179 603 238 603ZM248 20C183 20 125 70 125 163C125 218 158 268 206 300C284 261 355 217 355 143C355 66 308 20 248 20Z"/></g><g transform="matrix(.0135,0,0,-0.0135,55.374,0)"><path id="g117-42" d="M528 54L331 254L528 455L492 493L294 291L96 493L60 455L257 254L60 54L96 16L294 217L492 16L528 54Z"/></g><g transform="matrix(.0135,0,0,-0.0135,66.355,0)"><use xlink:href="#g113-50"/></g><g transform="matrix(.0135,0,0,-0.0135,72.858,0)"><path id="g113-49" d="M241 635C89 635 35 457 35 312C35 153 89 -12 240 -12C390 -12 443 166 443 312C443 466 390 635 241 635ZM238 602C329 602 354 454 354 312C354 172 330 22 240 22C152 22 124 173 124 313S148 602 238 602Z"/></g><g transform="matrix(.0095,0,0,-0.0095,79.41,-5.984)"><path id="g50-53" d="M462 177V227H365V632H320C217 496 116 350 21 208V177H284V109C284 43 280 38 190 31V0H451V31C369 38 365 43 365 108V177H462ZM284 227H88C155 336 218 430 282 519H284V227Z"/></g></svg> and <svg xmlns:xlink="http://www.w3.org/1999/xlink" xmlns="http://www.w3.org/2000/svg" style="vertical-align:-0.3625002pt" id="M2" height="12.2788pt" version="1.1" viewBox="-0.0498162 -11.9163 55.0104 12.2788" width="55.0104pt"><g transform="matrix(.0135,0,0,-0.0135,0,0)"><use xlink:href="#g113-50"/></g><g transform="matrix(.0135,0,0,-0.0135,6.503,0)"><use xlink:href="#g113-47"/></g><g transform="matrix(.0135,0,0,-0.0135,9.592,0)"><path id="g113-53" d="M456 178V225H360V632H320C217 496 115 347 20 206V178H280V106C280 40 276 34 189 27V0H445V27C364 34 360 39 360 106V178H456ZM280 225H82C149 335 214 431 278 520H280V225Z"/></g><g transform="matrix(.0135,0,0,-0.0135,16.096,0)"><use xlink:href="#g113-57"/></g><g transform="matrix(.0135,0,0,-0.0135,25.627,0)"><use xlink:href="#g117-42"/></g><g transform="matrix(.0135,0,0,-0.0135,36.607,0)"><use xlink:href="#g113-50"/></g><g transform="matrix(.0135,0,0,-0.0135,43.111,0)"><use xlink:href="#g113-49"/></g><g transform="matrix(.0095,0,0,-0.0095,49.662,-5.984)"><path id="g50-54" d="M158 548H390L417 615L410 623H122L83 318C105 326 143 337 185 337C296 337 350 275 350 188C350 116 308 42 225 42C164 42 122 74 100 93C90 101 82 99 72 92C60 82 51 68 50 59C48 46 52 38 66 24C82 9 125 -12 172 -12C225 -11 292 15 346 59C408 108 437 166 437 226C437 309 371 397 242 397C214 397 170 382 133 369L158 548Z"/></g></svg> with discrete incoming wakes are analyzed to identify the turbulent kinetic energy generation mechanism outside of the blade boundary layer. The results highlight the growth of turbulent kinetic energy at the bow apex of the wake and correlate it to the stress-strain tensors relative orientation. The production rate is analytically split according to the principal axes, and then terms are computed by using the simulation results. The analysis of the turbulent kinetic energy is followed both along the discrete incoming wakes and in the stationary frame of reference. Both direct numerical and large eddy simulation concur in identifying the same production mechanism that is driven by both a growth of strain rate in the wake, first, followed by the growth of turbulent shear stress after. The peak of turbulent kinetic energy diffuses and can eventually reach the suction side boundary layer for the largest Reynolds number investigated here with higher incidence angle. As a consequence, the local turbulence intensity outside the boundary layer can grow significantly above the free-stream level with a potential impact on the suction side boundary layer transition mechanism.

V. Michelassi

J. G. Wissink

Turbulent Kinetic Energy Production in the Vane of a Low-Pressure Linear Turbine Cascade with Incoming Wakes

About this journal

<p><em>International Journal of Rotating Machinery </em>publishes original research articles as well as review articles on all types of rotating machinery employing gas, vapor, particle, liquid, and their mixtures (including slurry) as the working substances.</p>


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<p>Chief Editor, Professor Amano, is based at the University of Wisconsin–Milwaukee and his research concentrates on the enhancement of energy production using wind, biomass, alternate fuels, and fossil energy sources.</p>


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International Journal of Rotating Machinery - Table of contents 2015

International Journal of Rotating Machinery | Hindawi

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International Journal of Rotating Machinery publishes original research articles as well as review articles on all types of rotating machinery employing gas, vapor, particle, liquid, and their mixtures (including slurry) as the working substances.

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International Journal of Rotating Machinery

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International Journal of Rotating Machinery