Hot Streak and Vane Coolant Migration in a Downstream Rotor

Ong, Jonathan; Miller, Robert J.

doi:10.1115/1.4003832

Cited by 47 publications

(27 citation statements)

References 21 publications

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“…The hot streak migrates downstream and through the vane passage, causing a 12 local increase in the adiabatic vane surface temperatures near the hot streak core. The hot streak remains coherent through the passage until the exit plane, in agreement with [17] and [19]. Figure 5 shows the hot streak migration through the vane passage for the first clocking position.…”

Section: A Solutionsupporting

confidence: 72%

“…Povey et al [18] numerically and experimentally studied how the hot streak affected heat transfer on turbine vanes. Ong and Miller [19] numerically studied the migration of the combustor hot streak through a vane and rotor passage and suggested cooling schemes to improve component cooling. The circumferential size of the hot streak and its effects were analyzed be He et al [20].…”

Section: Figure 1 -Volcanic Ash Deposition On Turbine Vanesmentioning

confidence: 99%

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Effect of Hot Streaks on Ash Deposition in an Uncooled Turbine Vane Passage

Casaday

Ameri

Bons

2012

50th AIAA Aerospace Sciences Meeting Including the New Horizons Forum and Aerospace Exposition

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Coal ash deposition was numerically modeled on an uncooled GE-E 3 high pressure turbine vane passage. A model was developed, in conjunction with Fluent™ software, to track individual particles through the turbine passage. Particles that strike the adiabatic surface become deposits if their viscosity drops below a predetermined value based on temperature. The computational model incorporated non-uniform inlet temperature conditions to account for the existence of a hot streak. The distribution of the temperature non-uniformity affects the location and amount of deposition measured on the nozzle guide vanes. Using a periodic condition that simulates one combustor nozzle per two nozzle guide vanes, the computational model predicts the optimal location for the combustor nozzle location to minimize total deposition rates in the vane passage. The deposition rates are strongly correlated to the average surface temperature of the vanes, but the clocking position with minimum deposition does not correlate to the clocking position with lowest average surface temperatures. The effect of particle size, or Stokes number, on deposition is studied and discussed. Nomenclature A = constant used to define critical viscosity model B = constant used to define critical viscosity model d P = diameter of particle 2 d le = vane leading edge diameter P S = probability of particle sticking St k = Stokes number, T P = temperature of particle V i = Velocity scale in Stokes number equation = capture efficiency = density of particle = viscosity of fluid = viscosity of particle  crit = viscosity of particle at critical sticking temperature

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Section: A Solutionsupporting

confidence: 72%

Section: Figure 1 -Volcanic Ash Deposition On Turbine Vanesmentioning

confidence: 99%

Effect of Hot Streaks on Ash Deposition in an Uncooled Turbine Vane Passage

Casaday

Ameri

Bons

2012

50th AIAA Aerospace Sciences Meeting Including the New Horizons Forum and Aerospace Exposition

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“…These results, obtained by simulation and also confirmed experimentally, reinforce the importance of understanding the behaviour of the fluid entering the vanes. Ong and Miller [26] numerically examined the effect of hot streaks in a turbine in which hot streaks were aligned with half of the vanes in an alternating fashion by solving the URANS equations and a mixing length model. They reported that the hot streaks enhanced the secondary flows in the rotor domain and caused an increase of the temperature on the blade pressure side.…”

Section: Literature Reviewmentioning

confidence: 99%

Effects of Non-Uniform Inlet Temperature Distribution on High-Pressure Turbine Blade Loading

Smith

Chang

Tavoularis³

2012

Int. J. Turbo Jet-Engines

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The effects of a non-uniform inlet field on the performance of a commercial, transonic, single-stage, high-pressure, axial turbine with a curved inlet duct have been investigated numerically by solving the unsteady Reynolds-averaged Navier-Stokes equations with the shear stress transport (SST) turbulence model. By adjusting the alignment of the experimentally-based inlet temperature field with respect to the stator vanes, two clocking configurations were generated: a Vane-Impinging (VI) case, in which each hot streak impinged on a vane and a Mid-Pitch (MP) case, in which each hot streak passed between two vanes. An additional case with a purely radial (PR) variation of inlet temperature was also investigated. In the VI case, it was observed that, as the hot streaks impinged on the stator vanes, they spread spanwise due to the actions of the casing passage vortices and the radial pressure gradient; this resulted in a stream entering the rotor with relatively low temperature variations. In the MP case, the hot streaks were convected undisturbed past the relatively cool vane section. Relatively high time-averaged enthalpy values were found to occur on the pressure side of the blades in the MP configuration.

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“…Hot streaks amongst other non-uniformities cause varying thermal stresses on turbine blades. These hot streaks are responsible for enhancing the secondary flows in the rotor domain and cause an increase of the temperature on the blade pressure side [14]. Authors [1] studied the effects of six hot streak circumferential positions relative to vane leading edge in a single-stage subsonic high-pressure turbine with 40 vanes and 82 blades and observed that surface pressure fluctuations on the rotor blade for the non-uniform total inlet temperature cases were increased as compared with the uniform case.…”

Section: Introductionmentioning

confidence: 98%

Experimental study of novel passive control methods to improve combustor exit temperature uniformity

2014

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The effect of non-uniform temperature flow which comes in contact with the turbine blades is of paramount importance since the thermal damage that occur to the blade during its operation, is governed by the non-uniformities present in the oncoming flow. This thermal damage leads to increased maintenance cost and reduced life-span of the turbine blades. This paper investigates the effectiveness of some novel passive control techniques to improve the temperature uniformity of the combustor exit flow to address the need to reduce the thermal damage and hence decrease the overall maintenance cost of the gas turbine system. The novel passive control techniques tested in this study include the use of streamlined body or guide vanes in the dilution zone of the combustor. For the guide vanes four different orientations were tested-0°, 30°, 60°, 90°. Extensive experimentation was conducted under different flow conditions. The deviation of the exit temperature from the equilibrium mixing temperature was used to compare the effectiveness of different passive control techniques. It was found that the 30 o guide vanes gave the most uniform temperature flow under majority of cases considered. On an average, the flow with 30 o guide vanes was about 15 % more uniform in temperature as compared to the staggered holes geometry with only 1 % higher pressure loss. The possible reason for this improvement is the combination of swirl and depth to which the dilution flow can enter the dilution zone and mix with the primary hot flow. The streamlined body came second with an improvement in pressure losses. Based on these experimental findings, the use of these guide vanes and streamlined body has potential in the gas turbine industry to deal with the high maintenance cost involved in these systems.

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Hot Streak and Vane Coolant Migration in a Downstream Rotor

Cited by 47 publications

References 21 publications

Effect of Hot Streaks on Ash Deposition in an Uncooled Turbine Vane Passage

Effect of Hot Streaks on Ash Deposition in an Uncooled Turbine Vane Passage

Effects of Non-Uniform Inlet Temperature Distribution on High-Pressure Turbine Blade Loading

Experimental study of novel passive control methods to improve combustor exit temperature uniformity

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