Parametric Surveys of the Effects of Wake Passing on High Lift LP Turbine Flows Using LES

Kunihiro, Tomikawa; Horie, Hiroyuki; Iida, Michihisa; Arakawa, Chuichi; Ooba, Yoshinori

doi:10.1115/fedsm2007-37208

Cited by 5 publications

(1 citation statement)

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“…The dumping factor and Smagorinsky constant are set as 25 and 0.1, respectively. As shown in previous studies, 31,32 these settings can accurately simulate the unsteady flow of an LPT suction side boundary layer at a low Reynolds number. The central difference method and the secondorder accurate backward Euler integral method are used to discretize the spatial derivatives.…”

Section: Simulation Settingmentioning

confidence: 65%

Study of the influence of multiple factors on the boundary layer of a high-lift LPT with the RBF-GA method

Sun,

Huang,

Kang

et al. 2023

Proceedings of the Institution of Mechanical Engineers, Part G:

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In a high-altitude cruising state, boundary layer separation exists in high-lift low-pressure turbines, and inflow conditions corresponding to different blade designs can directly affect the working efficiency of low-pressure turbines. In particular, the reduced frequency of wake and free-stream turbulence intensity in an inlet flow can greatly influence boundary layer separation and transition development. In this paper, the influence of different inflow turbulence intensities and reduced wake frequencies on the development of suction surface boundary layers in high-lift low-pressure turbines under the influence of upstream wakes is studied by numerical simulations and experiments. Due to the combination of inflow free-stream turbulence intensity and reduced wake frequency, many inflow conditions can be chosen in the design process, and the unsteady influence of upstream wakes complicates the boundary layer flow. In this paper, an RBF (radial basis function)-GA (genetic algorithm) machine learning method is used to explore the optimal inlet conditions corresponding to the minimum profile loss of the Pak-B profile. The search region of the free-stream turbulence intensity is 2%–4%, and the reduced frequency of the wake is changed by changing the flow coefficient, whose variation range is 0.7–1.3. It is found that the RBF-GA machine learning method can attain an inflow condition with a lower profile loss while using the same amount of computation and effort.

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Section: Simulation Settingmentioning

confidence: 65%

Study of the influence of multiple factors on the boundary layer of a high-lift LPT with the RBF-GA method

Sun,

Huang,

Kang

et al. 2023

Proceedings of the Institution of Mechanical Engineers, Part G:

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show abstract

Influence of the Upstream Wakes on the Boundary Layer of a High-Lift Low-Pressure Turbine at Positive Incidence

Sun

Tan

et al. 2020

J. Aerosp. Eng.

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A Comparison of the Wake Effects Generated by the Biased Triangle Bar and Traditional Cylinder Bar to the Boundary Layer on Suction Surface of LPT Blade

Sun

et al. 2020

International Journal of Turbo &Amp; Jet-Engines

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Considering the asymmetry of the low pressure turbine blade (LPT) wake at a low Reynolds number, the influence of asymmetric wakes which are similar to LPT wakes on the boundary layer of downstream blade rows in the near field is studied in the present paper, in order to increase wake flow prediction accuracy of the downstream blade without increasing the difficulty of the experiment or calculation load. Packb high-lift LPT airfoil was studied with CFX software. Following the analysis of the similarities between the wake generated by the cylinder bar and the triangle bar and the LPT blade wake in the near-field, the boundary layer flow characteristics on the suction surface under the different wakes were compared. In this research, it was found that the wakes of biased triangle bar shared more similarities with the LPT blade wake in the near field than the cylinder bar. Furthermore, the biased triangle bar wake was asymmetrical in terms of its centerline, and the separation bubble was suppressed while the calming effect was reduced after the wake-induced transition due to the asymmetry. And the time-averaged momentum thickness decreased by 7 % compared to the cylinder wake.

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Parametric Surveys of the Effects of Wake Passing on High Lift LP Turbine Flows Using LES

Cited by 5 publications

References 0 publications

Study of the influence of multiple factors on the boundary layer of a high-lift LPT with the RBF-GA method

Study of the influence of multiple factors on the boundary layer of a high-lift LPT with the RBF-GA method

Influence of the Upstream Wakes on the Boundary Layer of a High-Lift Low-Pressure Turbine at Positive Incidence

A Comparison of the Wake Effects Generated by the Biased Triangle Bar and Traditional Cylinder Bar to the Boundary Layer on Suction Surface of LPT Blade

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