Three-dimensional Navier-Stokes analysis of the tip clearance flow in linear turbine cascades

Liu, Jong-Shang; Bozzola, R.

doi:10.2514/6.1993-391

Cited by 3 publications

(4 citation statements)

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“…Moore and Moore (1991) performed an experiment where they eliminated the effect of endwall boundary layer by reducing the thickness to be less than the tip gap. Their measurements were used for code validation by Liu and Bozzola (1993) who incorporated the Baldwin-Lomax eddy viscosity model in their analysis of the tip clearance¯ow in linear turbine cascades. Choi (1992) resolved very well the tip leakage¯ow between rotating blades and stationary shroud, including ®ne-scale viscous motions such as vena contracta and separation on the blade tip.…”

Section: Introductionmentioning

confidence: 99%

Numerical simulation of turbulent cascade flows involving high turning angles

Lee

Yoo

1997

Computational Mechanics

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Numerical simulations of three dimensional turbulent incompressible¯ows through linear cascades of turbine rotor blades with high turning angles have been performed using a generalized k-e model which is a high Reynolds number form and derived by RNG (renormalized group) method to account for the variation of the rate of strain. The convective terms are approximated by using a second order upwind scheme to suppress numerical diffusion. Boundary-®tted coordinates are adopted to represent the complex cascade geometry accurately. For

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Section: Introductionmentioning

confidence: 99%

Numerical simulation of turbulent cascade flows involving high turning angles

Lee

Yoo

1997

Computational Mechanics

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“…In modern high load turbines, the loss induced by tip clearance leakage flow is remarkable. A number of investigations on tip clearance leakage flow have been performed by many researchers [9][10][11][12][13][14][15][16][17][18][19][20][21][22] to decrease the flow loss. Farokhi [9] analyzed the tip clearance loss in an axial flow turbine and proposed a model that accounts for tip pressure loading, relative wall motion and stage characteristics.…”

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confidence: 99%

“…In the model, the importance of pressure gradients along the blade chord was emphasized as a major factor influencing the tip leakage flow. Liu and Bozzola [11] investigated the tip clearance flow structures, leakage vortex, flow underturning, and the effect of the tip clearance on blade loading and losses by means of a three-dimensional code. The predicted results were in good agreement with the experimental data.…”

mentioning

confidence: 99%

Experimental investigation on unsteady pressure fluctuation of rotor tip region in high pressure stage of a vaneless counter-rotating turbine

Zhao

Liu

Wang

et al. 2009

Sci. China Ser. E-Technol. Sci.

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An experimental investigation has been performed to study the unsteady pressure fluctuation of rotor tip region in high pressure stage of a vaneless counter-rotating turbine. The experiment is carried out on a blow-down short duration turbine facility. The investigation indicates that the blow-down short duration turbine facility is capable of substituting continuous turbine facilities in most turbine testing. Through this experimental investigation, a distinct blade-to-blade variation is observed. The results indicate that the combined effects of vane wake, tip leakage flow, complicated wave systems and rotor wake induce the remarkable blade-to-blade variations. The results also show that the unsteady effect is intensified along the flow direction.counter-rotating turbine, pressure fluctuation, unsteady effect, short duration experimentIn the recent few years, more and more attentions have been paid to counter-rotating turbine (CRT) because it can offer some significant benefits compared with conventional two-stage turbine, such as the elevated thrust-to-weight ratio of aero-engine, the improved performance of aircraft, and so on. At present, 1-1 stage counter-rotating turbine has been used in some advanced active duty aero-engines, and vaneless counter-rotating turbine (VCRT, 1-1/2 stage counter-rotating turbine), which is composed of a highly loaded single stage high pressure turbine (HPT) and a vaneless counter-rotating single stage low pressure turbine (LPT), has been also applied in some up-to-date test engines in Euro-American developed countries. It is obvious that the VCRT will be widely adopted in real aero-engines in the future. From the 1950s, counter-rotating turbines have been carefully investigated [1][2][3][4][5][6][7][8] . Researchers focus on aerodynamic design of CRT, flow field analysis in CRT, and so on. These conclusions drawn by predecessors drive the development of the CRT technology.Some of approaches to increase efficiency or decrease loss need to be applied to enhancing specific work and reducing fuel consumption of gas turbine engines. In modern high load turbines, the loss induced by tip clearance leakage flow is remarkable. A number of investigations on tip clearance leakage flow have been performed by many researchers [9][10][11][12][13][14][15][16][17][18][19][20][21][22] to decrease the flow loss. Farokhi [9] analyzed the tip clearance loss in an axial flow turbine and proposed a model that accounts for tip pressure loading, relative wall motion and stage characteristics. A simple two-dimensional model for the calculation of the leakage flow over the blade tips of axial turbine was described in ref.[10]. In the model, the importance of pressure gradients along the blade chord was emphasized as a major factor influencing the tip leakage flow. Liu and Bozzola [11] investigated the tip clearance flow structures, leakage vortex, flow underturning, and the effect of the tip clearance on blade loading and losses by means of a three-dimensional code. The predicted

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“…Different versions of this scheme, which is in fact the most popular scheme used in the CFD community, have been implemented in 3D codes using a node centred approach (Chima, 1991, Dawes, 1992 or a cell centred approach (Amone, 1993, Calvert, 1997, Dawes, 1986, Jennions, 1993, Kang, 1993, Liu 1993, McNulty, 1994, Vuillot, 1993, Shabbir, 1996, and Zimmermann, 1992, with various implementations of the original numerical dissipation adapted to the type of mesh.…”

Section: Space Centred Schemesmentioning

confidence: 99%

The North Atlantic Treaty Organization

Suzuki¹

The U.S.-Japan Security Alliance

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According to its Charter, the mission of AGARD is to bring together the leading personalities of the NATO nations in the fields of science and technology relating to aerospace for the following purposes:-Recommending effective ways for the member nations to use their research and development capabilities for the common benefit of the NATO community;•-Providing scientific and technical advice and assistance to the Military Committee in the field of aerospace research and development (with particular regard to its military application);-Continuously stimulating advances in the aerospace sciences relevant to strengthening the common defence posture;-Improving the co-operation among member nations in aerospace research and development;-Exchange of scientific and technical information;-Providing assistance to member nations for the purpose of increasing their scientific and technical potential;-Rendering scientific and technical assistance, as requested, to other NATO bodies and to member nations in connection with research and development problems in the aerospace field.The highest authority within AGARD is the National Delegates Board consisting of officially appointed senior representatives from each member nation. The mission of AGARD is carried out through the Panels which are composed of experts appointed by the National Delegates, the Consultant and Exchange Programme and the Aerospace Applications Studies Programme. The results of AGARD work are reported to the member nations and the NATO Authorities through the AGARD series of publications of which this is one.Participation in AGARD activities is by invitation only and is normally limited to citizens of the NATO nations. Executive SummaryThe high performance of aircraft turbine engines -mainly oriented towards economy in civil engines and towards performance, economy and off-design reliability in military applications -depends on the correct design of gas flows in the engine. Today, this is mainly done by numerical computer simulation instead of the much more costly experimentation with hardware. The working group undertook to analyse the quality of computer codes in use and to show ways for improvement. Many discrepancies between codes were detected and it was recognized that even the researchers actively working in this field were unaware of the full scale of this phenomenon. The military will gain from the newly designed engines as well as from possible improvement in upgrades. It should be noted that this kind of down-toearth analysis, despite its merits, has not been undertaken on an international basis outside AGARD/RTO. La validation CFD des organes des propulseurs (AGARD AR-355) SyntheseLa recherche de hautes performances des turbomoteurs, motivee, pour les moteurs civils, principalement par la recherche d'economies, et pour les moteurs militaires par F amelioration des performances, les economies et la fiabilite dans des conditions hors tolerances, passe par une connaissance precise de la conception des ecoulements dans le moteur.Aujourd'hui, dans ...

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Three-dimensional Navier-Stokes analysis of the tip clearance flow in linear turbine cascades

Cited by 3 publications

References 0 publications

Numerical simulation of turbulent cascade flows involving high turning angles

Numerical simulation of turbulent cascade flows involving high turning angles

Experimental investigation on unsteady pressure fluctuation of rotor tip region in high pressure stage of a vaneless counter-rotating turbine

The North Atlantic Treaty Organization

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