Wang, Zhuo (2003)
Numerical Analysis of Massive Separation Control on Turbomachine Blades Using Synthetic Jet.
Technische Universität Darmstadt
Ph.D. Thesis, Primary publication
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Item Type: | Ph.D. Thesis | ||||||
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Type of entry: | Primary publication | ||||||
Title: | Numerical Analysis of Massive Separation Control on Turbomachine Blades Using Synthetic Jet | ||||||
Language: | English | ||||||
Referees: | Schäfer, Prof. Dr. Michael | ||||||
Advisors: | Stoffel, Prof. Dr.- Bernd | ||||||
Date: | 19 March 2003 | ||||||
Place of Publication: | Darmstadt | ||||||
Date of oral examination: | 21 January 2003 | ||||||
Abstract: | The study of massive separation control using synthetic jet based on the computation of RANS equations is carried out in this work. Above of all, the performance of turbulence models is discussed. A revised k-e model is proposed as the known turbulence models perform poor in reproducing the flow of airfoil at pre-stall or stall angle of attack. The modified turbulence model is validated on an NACA633-018 airfoil under the Reynolds number of 300,000. Good agreement with the experimental data is obtained. Therefore, the modified turbulence model is adopted to simulate the excitation of synthetic jet. The systematical investigation of the synthetic jet is conducted on the same NACA633-018 airfoil at stall angle of attack. The result shows that the jet is effective in controlling the massive separation. The large separation region cannot be completely removed by the synthetic jet. However, the flow structure can be regularized. The airfoil drag can be reduced by 22% when the frequency of excitation has a value between 1.5 and 2 times the characteristic frequency of fc=u?/(Ccosa), where u? is the free stream velocity, C the chord, and a the angle of attack. The characteristic frequency relates to a time scale of the main flow passing through the airfoil in flow direction. The jet intensity has little influence on the frequency range of efficient excitation. But the extent of the variations of lift and drag is large with intensive jet. Moreover, the best effect of excitation can be achieved when the synthetic jet locates at the natural separation point. The behavior of synthetic jet in controlling the massive separation on turbomachine blades is studied through an unconventional axial stator-rotor arrangement. The stator and rotor blades are constructed from NACA633-018 airfoil with stagger angles of 50 degrees. The result shows that the synthetic jet is efficient in controlling the massive separation in cascade flow when the frequency of excitation has a value between 1.5 and 2 times the characteristic frequency. The large separation can be transformed into several small separation bubbles. The drag of stator and rotor blades can be reduced by 50% and the loss of total pressure can be reduced to about one-third. |
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Uncontrolled Keywords: | Beeinflussung der Ablösung, künstlich erzeugter Strahl, RANS-Gleichungen, Turbulenzmodell, k-epsilon Modell | ||||||
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URN: | urn:nbn:de:tuda-tuprints-3082 | ||||||
Classification DDC: | 600 Technology, medicine, applied sciences > 620 Engineering and machine engineering | ||||||
Divisions: | 16 Department of Mechanical Engineering | ||||||
Date Deposited: | 17 Oct 2008 09:21 | ||||||
Last Modified: | 08 Jul 2020 22:45 | ||||||
URI: | https://tuprints.ulb.tu-darmstadt.de/id/eprint/308 | ||||||
PPN: | |||||||
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