scholarly journals Data Adaptive Spectral Analysis of Unsteady Leakage Flow in an Axial Turbine

2012 ◽  
Vol 2012 ◽  
pp. 1-7
Author(s):  
Konstantinos G. Barmpalias ◽  
Ndaona Chokani ◽  
Anestis I. Kalfas ◽  
Reza S. Abhari

A data adaptive spectral analysis method is applied to characterize the unsteady loss generation in the leakage flow of an axial turbine. Unlike conventional spectral analysis, this method adapts a model dataset to the actual data. The method is illustrated from the analysis of the unsteady wall pressures in the labyrinth seal of an axial turbine. Spectra from the method are shown to be in good agreement with conventional spectral estimates. Furthermore, the spectra using the method are obtained with data records that are 16 times shorter than for conventional spectral analysis, indicating that the unsteady processes in turbomachines can be studied with substantially shorter measurement schedules than is presently the norm.

2019 ◽  
Vol 19 (5) ◽  
pp. 1884-1896 ◽  
Author(s):  
Shanzhi Xu ◽  
Hai Hu ◽  
Linhong Ji ◽  
Peng Wang

2019 ◽  
Vol 15 (11) ◽  
pp. 3090
Author(s):  
Wu Sai ◽  
Wang Zhihui ◽  
Meng Sachura ◽  
Zheng Weijun ◽  
Shao Weiping

Author(s):  
Jan E. Anker ◽  
Ju¨rgen F. Mayer

This paper presents the simulation of the flow in a 1.5 stage low-speed axial turbine with shrouded rotor blades and focuses on the interaction of the labyrinth seal leakage flow with the main flow. The presented results were obtained using the Navier-Stokes code ITSM3D developed at University of Stuttgart. A comparison of the computational results with experimental data of this test case gained at Ruhr-Universita¨t Bochum verifies that the flow solver is capable of reproducing the leakage flow effects to a sufficient extent. The computational results are used to examine the influence of the leakage flow on the flow field of the turbine. By varying the clearance height of the labyrinth in the simulations, the impact of the re-entering leakage flow on the main flow is studied. As demonstrated in this paper, leakage flow not only introduces mixing losses but can also dominate the secondary flow and induce severe losses. In agreement with the experimental data the computational results show that at realistic clearance heights the leakage flow gives rise to negative incidence over a considerable part of the downstream stator which causes the flow to separate.


2018 ◽  
Vol 15 (4) ◽  
pp. 1460-1469 ◽  
Author(s):  
Rafael R Manenti ◽  
Wilker E Souza ◽  
Milton J Porsani

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