Results 261 to 270 of about 93,460 (307)

Influence of Casing Roughness on the Tip-Leakage Loss in a Linear Turbine Cascade

Volume 13B: Turbomachinery — Axial Flow Turbine Aerodynamics, 2023
Abstract The present experimental study was intended to investigate the impact of casing roughness on the tip leakage flow and the loss in a linear turbine cascade. Detailed flow measurements utilizing a five-hole probe, namely the so-called Oxford probe, and a miniaturized Pitot probe were made upstream and downstream of a row of steam ...
Lukas Huser, Stefan aus der Wiesche, Markus Schatz   +2 more
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Turbulence Characteristic and Loss of Transonic Turbine Tip Leakage Vortex With Endwall Motion Effect

Volume 10D: Turbomachinery — Multidisciplinary Design Approaches, Optimization, and Uncertainty Quantification; Turbomachinery General Interest; Unsteady Flows in Turbomachinery, 2022
Abstract Tip leakage flow is considered as an essential loss source within unshrouded high-pressure turbines. This work numerically investigated the flow physics associated with the prediction of the tip leakage loss in a transonic turbine cascade at a high Reynolds number.
Kai Zhou, Chao Zhou
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Vortical Structures and Loss Mechanism of Tip Leakage Flow In Subsonic and Transonic Turbine Stages

Volume 10B: Turbomachinery — Axial Flow Turbine Aerodynamics; Deposition, Erosion, Fouling, and Icing; Radial Turbomachinery Aerodynamics, 2022
Abstract Aerothermal behavior and performance of turbine blade squealer tip has been extensively studied, but previously mainly confined to very low speed flows. Some recent research efforts have revealed some distinctive tip heat transfer as well as aerodynamic characteristics in a transonic flow, many of which are confined to a linear ...
P. H. Duan, L. He
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Effects of inclined squealer rims on tip leakage vortex and loss in a transonic axial turbine

Proceedings of the Institution of Mechanical Engineers, Part A: Journal of Power and Energy, 2022
In this paper, to investigate the effects of inclined squealer rims on tip leakage flow and loss, numerical simulations have been performed on a transonic high-pressure turbine. Based on the geometry of prototype with conventional cavity tip, six modifications with different inclined rims are constructed.
Yufan Wang, Weihao Zhang, Yumo Mu, Shoumin Jiang, Yun Chen, Guangjian Ma   +5 more
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Optimization of Rotor Tip Cavity Shapes for Mitigating Aerodynamic Tip Leakage Losses

Journal of Propulsion and Power
Rotor blade tip leakage loss influences turbine stage efficiency. A parametric optimization method based on five design variables combined with Non-Linear Programming by Quadratic Lagrangian to optimize the turbine efficiency estimated from computational fluid dynamics analysis has been used to obtain estimates of the optimal cavity depth and split ...
Yingjie Chen, Le Cai, Yiyi Li, Songtao Wang, Murali Damodaran, Boo Cheong Khoo   +5 more
openaire   +1 more source

Blade Tip Leakage Loss Reduction by Means of Passive Tip Injection: Linear Cascade Wind Tunnel Results

Volume 2A: Turbomachinery, 2017
In the open literature, an innovative concept for turbine blade tip leakage loss reduction by means of passive tip injection was recently proposed. The present paper presents experimental results obtained for an unshrouded turbine blade corresponding to a 50 % reaction stage.
Rejek, Jonas, aus der Wiesche, Stefan, Willinger, Reinhard   +2 more
openaire   +2 more sources

Effects of blade rotation on axial turbine tip leakage vortex breakdown and loss

Proceedings of the Institution of Mechanical Engineers, Part G: Journal of Aerospace Engineering, 2016
The tip leakage vortex breakdown occurs under a few conditions in modern turbines, which leads to extra vortex breakdown losses, but the mechanisms of vortex breakdown and its influencing factors still remain unclear. This paper is a continuation of the previous effort and focuses on the effect of blade rotation on the leakage vortex dynamics in an ...
Jie Gao, Qun Zheng, Yunning Liu, Ping Dong   +3 more
openaire   +1 more source

Unsteady effects of vortex interaction on tip leakage vortex breakdown and its loss mechanism

Aerospace Science and Technology, 2018
Abstract In an unshrouded high-pressure turbine, tip leakage flow causes a loss of efficiency. The loss mechanisms of tip leakage flow were investigated mostly with steady uniform incoming conditions in previous studies. This paper investigated the unsteady aerodynamic performance of the tip leakage flow in a turbine stage by solving Unsteady ...
Kai Zhou, Chao Zhou
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Analysis of the relationship between turbulence characteristics and loss mechanism in the tip leakage flow of turbine blade

Proceedings of the Institution of Mechanical Engineers, Part A: Journal of Power and Energy, 2021
The tip leakage flow passed over the tip clearance makes the flow very complicated near the tip gap, and the interaction of the tip leakage vortex and endwall vortex enhances the instability of the flow. Accurately capturing detailed flow structures and investigating the relationship between the flow structures and loss are beneficial for ...
Hui Li, Xinrong Su, Xin Yuan
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Flow Mechanism and Loss Analysis of Tip Leakage Flow With Delayed Detached Eddy Simulation

Volume 2A: Turbomachinery, 2019
Abstract The complex leakage flow structure in the tip region of unshrouded rotor is a main source of turbine aerodynamic loss. Due to the complex turbulence characteristics of the tip leakage flow, the widely used Reynolds Averaged Navier-Stokes (RANS) approach may fail to accurately predict the multi-scale turbulent flow and the ...
Hui Li, Xiutao Bian, Xinrong Su, Xin Yuan   +3 more
openaire   +1 more source