Wake Passage Research Articles

Clocking effects on aerodynamics of a gas turbine low pressure axial turbine, part 2: Unsteady simulation

Unsteady, viscous compressible flow is numerically simulated within first two stages of a low pressure turbine of a gas turbine engine under different clocking of its stator blades rows. Zonal DES turbulence modeling has been used for flow simulations. Time-dependent wake flow trajectory is modeled and visualized within the blades passages. All characteristics of the passage wake flow, including its V-shape motion, re-orientation, elongation, expansion, and stretching, are properly simulated. Unsteady flow field results together with those of general aerodynamic performance of the optimum and worst clocking cases are presented and compared with each other. Analyses of the flow simulation results showed that the optimum clocking of the blades rows occurs while the upstream wake flow impinges on the downstream stator blade leading edge region. Final results demonstrated that under the optimum clocking of the second stator, the inlet total pressure of the second rotor blades row and its output power increase by 0.1% and 0.336%, respectively. Consequently, efficiency of the second stage increases by 0.35%. In addition, total output power of the whole two stages increases by 0.237%.

Modeling of Wake Effects in Steady State Mixing Plane Simulations of a High Lift Turbine Cascade with Different Combinations of Wake Passing Frequency and Wake Orientation

Due to operation at low Reynolds numbers, low pressure turbines of aircraft engines mostly show large laminar boundary layers and transitional separation bubbles which considerably change their viscous losses when interacting with impinging wakes. The change of loss depends on several wake parameters, among others on wake passing frequency and wake orientation. In the present work, these parameters are expressed in terms of Strouhal number and flow coefficient and their influence is investigated by means of unsteady Reynolds-averaged Navier-Stokes (RANS) simulations. Different combinations of both wake parameters which are typical of aircraft engine conditions, are prescribed upstream of a high lift turbine cascade, while the Reynolds number and Mach number are kept constant. The solver TRACE by DLR and MTU Aero Engines together with the γ − Re Θ transition model by Langtry and Menter has been used. Further, the wake profile is representative for upstream turbine profiles and is prescribed by a correlation framework which has been calibrated in previous work. A newly developed quasi-unsteady wake model (QUWM) is applied in order to model the effects of periodically passing wakes in steady state simulations involving mixing plane interfaces. It is shown that the gap between unsteady and steady state simulations is narrowed significantly by the QUWM while still maintaining quick turnaround times that are crucial in industrial flow solver applications.

Tower shadow induced blade loads for an extreme‐scale downwind turbine

AbstractThe downwind rotor configuration provides a structural advantage compared with an upwind design. However, tower shadow has long been a concern for downwind systems. The tower shadow negatively affects the blade by introducing a load impulse during the wake passage. An aerodynamic fairing could shroud the tower reducing the wake. However, there is no clear consensus on the importance of a tower shadow for utility‐scale wind turbines. Simulations were conducted in FAST to determine the general parameters that influence the importance of the tower shadow effect for the differently sized wind turbines. The lock number of the blade was a significant driving quantity. Lower lock numbers (typical of small‐scale wind turbines) lead to greater relative fatigue damage from tower shadow effects. It was determined that a fairing is very helpful for small‐scale wind turbines operating in a low‐turbulence environment (such as a subscale wind tunnel test). However, the tower shadow increased the damage equivalent loading on an extreme scale blade by less than 5% in a turbulent environment. These results indicate that the cost of a tower fairing is likely unnecessary for utility‐scale wind turbines in operation.

Influence of Blade Loading Profile on Wake Dynamics in High-Pressure Turbine Cascades

The influences of blade loading profile on wake convection and wake/wake interaction were studied in two different blade designs for high-pressure (HP) turbines (front-loaded (FL) and aft-loaded (AL)), installed in linear cascades. A high-speed moving bar (HSMB) apparatus replicated wake shedding, and a closed loop wind tunnel produced engine-relevant Mach numbers (Ma = 0.7) and Reynolds numbers (Re = 3 × 105). The FL blades had approximately 10% greater total pressure loss when operated with unsteady wake passage. Phase conditioned particle image velocimetry (PIV) measurements were made in the aft portion of the blade channel and downstream of the blade trailing edge. The turbulence kinetic energy (TKE) in the wake was approximately 30% higher for the FL blades when the wake entered the measurement field-of-view. The pressure field in the upstream region of the FL blade design is believed to induce high magnitude strain rates—leading to increased TKE production—and more aggressively turn and dilate the unmixed wake—leading to increased mixing related losses. The higher TKE for the FL blades largely dissipated, being approximately equal to the AL wake by the time the wake reached the end of the blade passage. The interaction of the convected wake with the wake from the blade trailing edge caused periodic vortex shedding at the second harmonic of the convected wake frequency. This interaction also modulated the strength of the trailing edge wake. However, little difference was found in the modulation amplitudes between different cases due to similar strengths of the convected wakes in this region. The higher wake TKE in the upstream portion of the blade channel for the FL blades, therefore, is expected to be the cause of the higher total pressure loss.

A POD-Based Procedure for the Split of Unsteady Losses of an LPT Cascade

A time-resolved particle image velocimetry (TR-PIV) system has been employed to investigate the unsteady propagation of upstream wakes in a low-pressure turbine cascade. Data are obtained in the steady state condition and for two passing wake reduced frequencies. The study is focused on the identification and split of the different dynamics responsible for deterministic and random oscillations, thus loss generation by means of a new procedure based on proper orthogonal decomposition (POD). The paper takes advantage of the properties of POD that reduce the data set to a low number of modes that represent the most energetic dynamics of the system. It is clearly shown that the phase averaged flow field can be represented by a few number of POD modes related to the wake passing event for the unsteady cases. Proper orthogonal decomposition is also able to capture flow features affecting the instantaneous flow field not directly related to the wake passage (i.e., the vortex shedding phenomenon induced by the intermittent separation developing between adjacent wakes), which are smeared out in the phase averaged results. A procedure exploiting the biorthogonality condition of the POD modes, and the related temporal coefficients, has been developed for the quantification of the contribution due to the different POD modes to the overall turbulence kinetic energy production, or, equivalently, the mean flow energy dissipation rate. Results into the paper clearly show that losses due to wake migration, boundary layer and vortex shedding related phenomena can be distinguished and separately quantified for the different tested conditions.

Coherent Structures Formation During Wake-Boundary Layer Interaction on a LP Turbine Blade

Particle Image Velocimetry (PIV) measurements have been analyzed in order to characterize the dynamics of coherent structures (eddies and streaks) within the suction side boundary layer of a low pressure turbine cascade perturbed by impinging wakes. To this end, the instantaneous flow fields at low Reynolds number and elevated free-stream turbulence intensity level (simulating the real condition of the blade row within the engine) were investigated in two orthogonal planes (a blade-to-blade and a wall-parallel plane). Proper Orthogonal Decomposition (POD) has been employed to filter the instantaneous flow maps allowing a better visualization of the structures involved in the transition process of the boundary layer. For the unsteady case properly selected POD modes have been also used to sort the instantaneous PIV images in the wake passage period. This procedure allows computing phase-averaged data and visualizing structures size and intensity in the different parts of the boundary layer during the different wake passage phases. The contributions to the whole shear stress due to the largest spanwise oriented scales at the leading and trailing boundaries of the wake-jet structures and those associated with streaky structures observed in the bulk of the wake are discussed. Instantaneous images in the wall-parallel plane are filtered with POD and they allow us to further highlight the occurrence of low and high speed traveling streaks (Klebanoff mode). The periodic advection along the suction side of the high turbulent content regions carried by the wakes anticipates both formation and sinuous instability of the streaks inside the boundary layer as compared with the steady case. The dynamics driving the breakdown of the streaks and the consequent formation of nuclei with high wall-normal vorticity have been found to be almost the same in the steady and the unsteady cases. Auto-correlation of the instantaneous images are also presented in order to highlight analogies and differences in the size and spacing of streaks in the two cases. These results are also compared with the available literature concerning simplified geometries (i.e flat plate) operating under steady inflow.

Film Cooling Parameter Waveforms on a Turbine Blade Leading Edge Model With Oscillating Stagnation Line

It is necessary to understand how film cooling influences the external convective boundary condition involving both the adiabatic wall temperature and the heat transfer coefficient in order to predict the thermal durability of a gas turbine hot gas path component. Most studies in the past have considered only steady flow, but studies of the unsteadiness naturally present in turbine flow have become more prevalent. One source of unsteadiness is wake passage from upstream components which can cause fluctuations in the stagnation location on turbine airfoils. This in turn causes unsteadiness in the behavior of the leading edge coolant jets and thus fluctuations in both the adiabatic effectiveness and heat transfer coefficient. The dynamics of h and η are now quantifiable with modern inverse heat transfer methods and nonintrusive infrared thermography. The present study involved the application of a novel inverse heat transfer methodology to determine time-resolved adiabatic effectiveness and heat transfer coefficient waveforms on a simulated turbine blade leading edge with an oscillating stagnation position. The leading edge geometry was simulated with a circular cylinder with a coolant hole located 21.5 deg downstream from the leading edge stagnation line, angled 20 deg to the surface and 90 deg to the streamwise direction. The coolant plume is shown to shift in response to the stagnation line movement. These oscillations thus influence the film cooling coverage, and the time-averaged benefit of film cooling is influenced by the oscillation.

J0520203 周期的後流通過の影響を受ける翼面境界層の流動解析

J0520203 周期的後流通過の影響を受ける翼面境界層の流動解析

Experimental investigation of the interaction between incoming wakes and instability mechanisms in a laminar separation bubble

The present paper reports the results of a detailed experimental study on the interaction process between incoming wakes and a laminar separated boundary layer. Experimental investigations have been carried out, for a low Reynolds number case, over a flat plate installed within a double contoured test section designed to produce an adverse pressure gradient typical of Ultra-High-Lift turbine blade profiles. Measurements have been performed by means of a single-sensor hot-wire anemometer. The phase-locked ensemble averaging technique, synchronized with the wake frequency, has been adopted to reconstruct the boundary layer space–time evolution in terms of ensemble-averaged velocity and velocity root mean square. These experimental data have been exploited in order to investigate how the unsteady incoming flow interacts with the instability mechanisms of the boundary layer to drive transition. Two main effects of wake passage were found. The low frequency disturbance associated with the wake passage triggers the Kelvin–Helmholtz instability process developing in the shear layer in the time interval between wakes. Moreover, the temporary reduction/suppression of the separation bubble observed when the incoming wake reaches the separated flow region has been found to be driven by linear stability mechanisms, which promote a quick amplification of the high frequency velocity fluctuations carried by wakes.

Wake-Induced Bypass Transition over a Flat Plate under Favorable and Adverse Pressure Gradients

The present study investigates wake-induced bypass transition of boundary layers on a flat plate subjected to favorable and adverse pressure gradients. The aim is to exploit unsteady effects in order to design an aft-loaded turbine blade without increasing the profile loss, as has been achieved for low pressure turbine blades. First of all, this fundamental study is to reveal the effect of the Strouhal number, which changed by using different numbers of wake generating bars. Detailed boundary layer measurements were conducted using two hot-wire probes. A passage-contouring device was employed to generate a pressure gradient on the test model, which was typical to that generated by an aft-loaded turbine blade. A spoked-wheel-type wake generator was used to create periodic wakes in front of the flat plate. It was found that the wake passage induces a significant change in the flow structure downstream of the flow acceleration region.

J055033 平板翼面上を通過する周期的後流の速度計測に関する実験的研究(〔J055-03〕流体機械の研究開発におけるEFD/CFD(3))

The present study investigates wake-induced bypass transition of boundary layers on a flat plate subjected to favorable and adverse pressure gradients. The aim is to exploit unsteady effects in order to design a turbine blade without increasing the profile loss, as has been achieved for low pressure turbine blades. First of all, this fundamental study is to reveal the effect of wake passing frequency. Detailed boundary layer measurements were conducted using hot-wire probe. A passage-contouring device was employed to generate a pressure gradient on the test model, which was typical to that generated by an turbine blade. A wake generating squirrel cage was used to create periodic wakes in front of the flat plate. It was found that the wake passage induces a temporary turbulence promoting in the flow over a flat plate surface.

First lunar wake passage of ARTEMIS: Discrimination of wake effects and solar wind fluctuations by 3D hybrid simulations

The spacecraft P1 of the new ARTEMIS (Acceleration, Reconnection, Turbulence, and Electrodynamics of the Moon's Interaction with the Sun) mission passed the lunar wake for the first time on February 13, 2010. We present magnetic field and plasma data of this event and results of 3D hybrid simulations. As the solar wind magnetic field was highly dynamic during the passage, a simulation with stationary solar wind input cannot distinguish whether distortions were caused by these solar wind variations or by the lunar wake; therefore, a dynamic real-time simulation of the flyby has been performed. The input values of this simulation are taken from NASA OMNI data and adapted to the P1 data, resulting in a good agreement between simulation and measurements. Combined with the stationary simulation showing non-transient lunar wake structures, a separation of solar wind and wake effects is achieved. An anisotropy in the magnitude of the plasma bulk flow velocity caused by a non-vanishing magnetic field component parallel to the solar wind flow and perturbations created by counterstreaming ions in the lunar wake are observed in data and simulations. The simulations help to interpret the data granting us the opportunity to examine the entire lunar plasma environment and, thus, extending the possibilities of measurements alone: A comparison of a simulation cross section to theoretical predictions of MHD wave propagation shows that all three basic MHD modes are present in the lunar wake and that their expansion governs the lunar wake refilling process.

Comparison of Steady and Unsteady RANS Heat Transfer Simulations of Hub and Endwall of a Turbine Blade Passage

The necessity of performing an unsteady simulation for the purpose of predicting the heat transfer on the endwall surfaces of a turbine passage is addressed. This is measured by the difference between the two solutions obtained from a steady simulation and the time average of an unsteady simulation. The heat transfer coefficient (Nusselt number) based on the adiabatic wall temperature is used as the basis of the comparison. As there is no film cooling in the proposed case, a computed heat transfer coefficient should be a better measure of such difference than, say, a wall heat flux. Results show that the effect of unsteadiness due to wake passage on the pressures and recovery temperatures on both hub and casing is negligible. Heat transfer on the endwalls, however, is affected by the unsteady wake; the time-averaged results yield higher heat transfer; in some regions, up to 15% higher. The results for the endwall heat transfer were compared with results in open literature and were found to be comparable.

“Little Old Joyce From Pasadena”: The XXII North American James Joyce Conference, San Marino-Pasadena, 12–16 June 2011

“Little Old Joyce From Pasadena”: The XXII North American James Joyce Conference, San Marino-Pasadena, 12–16 June 2011 Dermot Kelly For the latest news about Joyce and the world of Joyce studies, visit the JJQ blog “Raising the Wind” at <http://jjqblog.wordpress.com>. The XXII North American James Joyce Conference opened with, among five concurrent sessions, the “Rock Reads Joyce” panel, a searching hour-and-a-quarter on versions, references, and echoes of the famous Dubliner in the voices of Syd Barrett, the lost singer and guitarist of Pink Floyd, memorialized in “Shine On You Crazy Diamond,” who actually recorded “Lean Out of the Window, Goldenhair” from Chamber Music; Van Morrison, who has included the name of his southern countryman in songs at least twice; and Bruce Springsteen, whose “Thunder Road” bears comparison with “Araby” in terms of Mariolatry. Cheryl Herr led the exploration of the Syd Barrett connection, using sound and video to tantalizing effect, while Lauren Onkey, from the Rock and Roll Hall of Fame, unable to attend due to a family emergency, sent in her thought-provoking discourse on a video that included footage of the Belfast cowboy in performance, and I sang parts of “Thunder Road” interspersed with moments of reverie over Mangan’s sister. As if the proposed intersections could not get more spectral and fugitive, the next hour included a session in which the imagery of fellatio in “Lotus Eaters” was elaborated on by Anna Finn and the resonance of Benjamin Franklin among the “Irish heroes” of “Cyclops” was amplified by Thomas Jackson Rice. Suitably inspired conversation flowed over lunch at the Huntington mausoleum, and events gusted to a cosmic scale afterwards during a plenary talk by Jeffrey Drouin entitled “The Einstein of English Fiction.” Some participants carried on the dialogue at a more psychodramatic level in an hour devoted to the strange language of “Circe,” ably presided over by Alexander Starkweather Fobes and Tabatha Hibbs. That happy Monday ended with interested members of the public welcomed into the Huntington to hear the poets Eavan Boland, Sinead Morrissey, and Paul Muldoon read as part of the Arroyo Literary Festival. The involvement of the public engendered a congenial atmosphere pervading the Tuesday and Wednesday afternoons in the aptly named [End Page 7] Friends’ Hall as Fionnula Flanagan delivered an electrifying reading of “Counterparts” that gave rise to an impassioned discussion the next day led by Austin Briggs and Margot Norris. The conference organizers, along with their partners in “Imagine Ireland,” an initiative of “Culture Ireland” and the Pasadena Public Library, deserve the highest praise for fostering such a uniquely engaging and welcoming atmosphere. These events both broadened and narrowed the focus wonderfully, lending credence to Camille Paglia’s assertion, in Sexual Personae, that “Joyce has only one subject—Ireland.”1 In that spirit, the “Irish History” panel chaired by Sean Latham achieved both global reach and local grounding as Robert Colson, Seokmoo Choi, and Srinivas Venkata tackled the two-sided attack on nationalism in “Cyclops,” Ireland’s partnership in empire, and the wounding reverberations of the Charles Stewart Parnell affair in A Portrait respectively. Wednesday morning’s “Letters, Codes, and Notebooks” panel, featuring William Brockman, Rodney Sharkey, and Anthony Fusco, lured its audience into the pursuits of handwritten correspondence, conspiratorial codes, and the genesis of a Finnegans Wake passage. In this way, three inspirational days went by in what seemed the blink of an eye with hardly a moment spared to glance at the wonders of the Ellesmeer Chaucer manuscript, open to the “Cook’s Tale,” the Gutenberg Bible, and the Botanical Gardens. Early Thursday found intrepid delegates in the Beckman Institute Auditorium at Cal Tech hearing Peter Quadrino adumbrate Salvador Dali’s haunting of A Portrait of the Artist and Akira Tamura trace links between Ulysses and Irish Impressionists. Then it was time for those remaining to scale the dizzying heights of “Lacan, Badiou, and the Inconsistent Multiplicity of Ulysses” in a plenary session with Tony Thwaites and Shelly Brivic, who made a beguiling pair applying the lessons of French psychoanalysis and philosophy to the book that brought so many pilgrims to southern California, the former navigating “On the Edge of the...

Upstream wake–secondary flow interactions in the endwall region of high-loaded turbines

A detailed experimental and numerical investigation of the unsteady interaction of secondary flow vortices in turbine endwall region was performed with the effect of upstream periodic wakes. The flow field was investigated respectively in a linear turbine cascade and a turbine rotor. The study revealed the physical mechanisms of unsteady interaction between upstream wake and secondary vortices. The influence of the upstream wake on the performance of turbine endwall region was also discussed. The flow field at the exit of the turbine blade row showed a decrease in passage vortex strength and loss due to the upstream wake transport. Two interaction mechanisms are proposed whereby passage vortex loss decreases. They are the upstream wake–pressure side leg of the horseshoe vortex interaction and the upstream wake–passage vortex interaction. The transport of upstream wake can suppress the development of pressure side leg of the horseshoe vortex and passage vortex because of the “negative jet” influence of the wake.

The Music of Joyce's Vernacular Voices

The Music of Joyce's Vernacular Voices Margot Norris (bio) Correction: In the this issue of *Modernism/Modernity* (16.2, April 2009) the titles of the essays by Margot Norris (pp. 377–382) and Maud Ellmann (pp. 383–390) were inadvertently switched—in the table of contents as well as in the essays themselves. The correct title for Margot Norris’s essay is “The Music of Joyce’s Vernacular Voices”; and the correct title for Maud Ellmann’s essay is “Joyce’s Noises.” We regret this error. This error has been fixed on the Project MUSE HTML version of the article. "[M]aybe the most beautiful extant recording of an unaccompanied speaking voice." That is how Douglas Wolk in a January 21, 2004 article in The Seattle Weekly describes the famous 1929 recording that James Joyce made of a section of "Anna Livia Plurabelle." He goes on to say, "For eight minutes, a liquid-voiced Joyce impersonates the sound of the world talking to itself: Two washerwomen chat on the banks of a river as night falls, and they turn into a tree and a stone. His Irish accent, in fact, is so thick that it's hard for an American, 75 years later, to hear the crackling recording as language, rather than as water and music."1 This description of Joyce's prose language as sonic, as simulating the sound of music, has, of course, inspired a huge number of composers to transform it into musical compositions. Scott Klein in a superb essay on "James Joyce and Avant-garde Music" points out that Joyce's influence, as an author, on the world of modern music may be unprecedented.2 The early works, especially Joyce's poems, stimulated tonal and Romantic arrangements, and Klein cites Myra Russell as counting 140 composers who have set the poems to music. Samuel Barber not only set such poems as "I Hear an Army" to music, but in 1947, eight years after the publication of Finnegans Wake, he produced Nuvoletta, inspired by the sounds of the Wake. However, as Klein discusses at length, Finnegans Wake chiefly influenced avant-garde composers, and John Cage's Roaratorio, An Irish Circus on 'Finnegans Wake' produced in 1979, is clearly the most famous of these productions. But I would like to point to a different feature of that beautiful Finnegans Wake passage Joyce recorded in his thick Irish accent in 1929, and relate its aural qualities to an entirely different set of early twentieth-century [End Page 377] poetic practices and aesthetic concerns. Like Molly Bloom's famous soliloquy at the end of Ulysses, the dialogue of the washerwomen in "Anna Livia Plurabelle" underlines the aesthetic qualities of ordinary conversational speech, that is, the beauty of vernacular language. And in its heavily accented Irish tones, this female speech is inflected with a working class idiom and with Irish ethnicity. This semantic aspect of the sonic quality of the vernacular speech in Joyce's later work may be fruitfully related to a poetic consciousness and a poetic practice occurring across the Atlantic in Joyce's day, in the poetry of the Harlem Renaissance. Modernist studies in the last decade or two have begun to attend to the importance of looking at high modernism in relation to vernacular discourses. A 2004 University of Pennsylvania dissertation by Matthew Hart titled "Synthetic Vernacular Poetry and Transatlantic Modernism 1922–2002" treats twentieth-century vernacular poetry with its attention to race, region, and nation as a response to the privileging of the internationalist current in high modernism.3 And Michael North's 1994 study The Dialectic of Modernism: Race, Language, & Twentieth Century Literature draws attention to the "linguistic mimicry and racial masquerade" already in practice in the discourses of high modernists such as Eliot, Pound, Stein, and William Carlos Williams.4 These studies complicate T. S. Eliot's problematic positioning of vernacular speech—and particularly of its class markers—in the famous pub passage in The Waste Land. "When Lil's husband got demobbed, I said—/I didn't mince my words, I said to her myself [. . . .] Now Albert's coming back, make yourself a bit smart./ He'll want to know what you...

Turbulence measurements in the inlet plane of a centrifugal compressor vaneless diffuser

Detailed flow measurements at the inlet of a centrifugal compressor vaneless diffuser are presented. The mean 3-d velocities and six Reynolds stress components tensor are used to determine the turbulence production terms which lead to total pressure loss. High levels of turbulence kinetic energy were observed in both the blade and passage wakes, but these were only associated with high Reynolds stresses in the blade wakes. For this reason the blade wakes mixed out rapidly, whereas the passage wake maintained its size, but was redistributed across the full length of the shroud wall. Peak levels of Reynolds stress occurred in regions of high velocity shear and streamline curvature which would tend to destabilize the shear gradient. Four regions in the flow are identified as potential sources of loss - the blade wake, the shear layers between passage wake and jet, the thickened hub boundary layer and the interaction region between the secondary flow within the blade wake and the passage vortex. The blade wakes generate most turbulence, with smaller contributions from the hub boundary layer and secondary flows, but no significant contribution is apparent from the passage wake shear layers.

G1103 周期的後流と平板境界層との干渉現象に関する研究 : 圧力勾配の効果に関して(2)(GS11 干渉,乱流,一般セッション)

G1103 周期的後流と平板境界層との干渉現象に関する研究 : 圧力勾配の効果に関して(2)(GS11 干渉,乱流,一般セッション)

G1103 周期的後流と平板境界層との干渉現象に関する研究 : 圧力勾配の効果に関して(1)(GS11 干渉,乱流,一般セッション)

G1103 周期的後流と平板境界層との干渉現象に関する研究 : 圧力勾配の効果に関して(1)(GS11 干渉,乱流,一般セッション)

Influence of Wake Passing Frequency and Elevated Turbulence Intensity on Transition.

Experimental results from a study of the effects of passing wakes upon laminar-to-turbulent transition in a low-pressure turbine passage are presented. The test section simulates the effects of unsteady wakes resulting from rotor-stator interaction In turbine blade boundary layers and separated flow regions over suction surfaces. Single-wire thermal anemometry techniques are used to measure time-resolved and phase-averaged wall-normal profiles of streamwise velocity, turbulence intensity, and intermittency at multiple streamwise locations over the turbine airfoil suction surface. The Reynolds number based on suction surface length and stage exit velocity is 5 X 10 4 . This low Reynolds number would apply to small engines flying at high altitude