...Dingxi Wang; Sen Zhang; Xiuquan Huang; Huang Huang The paper proposes a novel numerical method called coupled time and passage spectral method for an efficient resolution of far upstream wakes in an unsteady analysis of flow field within generic multiple blade rows. The proposed method is a very...

...Pawel J. Przytarski; Andrew P. S. Wheeler In this paper, we study the effect of rotor-stator axial gap on midspan compressor loss using high-fidelity scale-resolving simulations. For this purpose, we mimic the multi-stage environment using a new numerical method that recycles wake unsteadiness from...

...Jeffrey P. Bons; Jon Pluim; Kyle Gompertz; Matthew Bloxham; John P. Clark The synchronous application of flow control in the presence of unsteady wakes was studied on a highly loaded low pressure turbine blade. At low Reynolds numbers, the blade exhibits a nonreattaching separation bubble under...

... of blades with the same airfoil profiles. The CFD analysis was performed for the cascade at subsonic inlet and transonic exit conditions. Boundary layer growth, wake formation, and shock boundary layer interactions were observed in the two-dimensional computations. The flow field showed the presence...

... effects of the stator wake interaction, the secondary flow interaction, and the potential field interaction on the unsteady loss generation at the rotor exit. Furthermore, the impact on the turbine design of quantifying the loss in terms of the entropy loss coefficient, rather than the more familiar...

... the same Mach number level. Results showed that the vortex generators reduce the separation in the 2D-duct but have no distinct influence on the separation within the turbine duct due to wakes as well as strong secondary flow effects. Figure 1 shows the AIDA test setup with 5HP and static pressure...

... wake interaction, aft-rotor upstream influence, hub-endwall secondary flows, and front-rotor tip-vortices to interaction tone noise are dissected and quantified. Based on this investigation, the CRP was redesigned for reduced noise incorporating a clipped rear-rotor and increased rotor-rotor spacing...

...Mark G. Turner; Steven E. Gorrell; David Car This paper shows a comparison of an unsteady simulation using turbo and an average passage simulation for a two blade row configuration consisting of a wake generator followed by a transonic rotor. Two spacings were simulated, both close and far...

..., 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...

... and Reynolds numbers at engine relevant levels and of coolant mass flows. The results for steady and periodic unsteady inflows with highly turbulent wakes created by cylindrical bars moving upstream in a plane parallel to the cascade are compared as two-dimensional surface plots, laterally averaged film...

... wakes, circumferential pressure gradients, purge flows, and blade lead edge blockages. Part 1 of this study utilizes a wheelspace sector cascade rig for the purpose of gathering fundamental data on flow and thermal effects in a nonrotating environment. This experimental rig is a simplified screening...

...S. P. R. Nolan; B. B. Botros; C. S. Tan; J. J. Adamczyk; E. M. Greitzer; S. E. Gorrell The effect on rotor work of the phase of an upstream wake relative to the rotor is examined computationally and analytically for a transonic blade row. There can be an important impact on the time-mean...

... and vanes, a three component Doppler laser-two-focus velocimeter was used. The results of the time resolved pressure traverse measurements in the axial gaps as well as the analysis of the tip leakage flow show the propagation of the wakes and the potential upstream influence, which can be clearly detected...

...Sébastien Lemire; Huu Duc Vo This paper proposes a new technique to reduce the noise generated by rotor-stator interaction (tonal noise) in fans and compressors. The method involves the use of single dielectric barrier discharge (plasma) actuators near the blade trailing edge to reduce blade wakes...

...S. Olson; S. Sanitjai; K. Ghosh; R. J. Goldstein This study investigates the effect of wakes in the presence of varying levels of background freestream turbulence on the heat (mass) transfer from gas turbine blades. Measurements using the naphthalene sublimation technique provide local values...

...Francesco Soranna; Yi-Chih Chow; Oguz Uzol; Joseph Katz This paper examines the response of a rotor blade boundary layer and a rotor near-wake to an impinging wake of an inlet guide vane (IGV) located upstream of the rotor blade. Two-dimensional particle image velocimetry (PIV) measurements...

...Ali A. Ameri; David L. Rigby; Erlendur Steinthorsson; James Heidmann; John C. Fabian The effect of the upstream wake on the time averaged rotor blade heat transfer was numerically investigated. The geometry and flow conditions of the first stage turbine blade of GE’s E 3 engine with a tip clearance...

.... Unsteady wakes, inherent in real turbomachinery flows, were generated using a moving bar mechanism. A turbulence grid generated a freestream turbulence level that is believed to be typical of LP turbines. Measurements were taken across a Reynolds number range 50,000–220,000 at three reduced frequencies...

... magnitudes and the largest I A L are generally present at any particular wake location for the RR or SA configurations, regardless of the film cooling blowing ratio and number of holes. The SA holes also generally produce the highest local peak C p magnitudes. I A L magnitudes are generally lowest...

... Turbines,” ASME Paper No. GT2008-50589 ) on the design of high-lift airfoils, the profile is forward loaded. The separate and combined effects of roughness and wake passing are compared. On a front loaded blade, the effect of incidence becomes more important and the consequences in terms of cascade losses...