Aerospace Research - ISTC Funded Projects 1994-2009

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Project Number: #0199 Enhancement of Flight Performance, Economy and Efficiency Full and Short Title: Development of New Methods of Laminar Flow Control and Turbulent Drag Reduction. Turbulent Drag Reduction Tech Code/Area/Field: SATAER/Space, Aircraft and Surface Transportation/Aeronautics Status: Technology Project underway Development Phase: Technology development Allocated Funding: $572,995 (EU) Commencement date: (starting date) April 1, 1995 Duration: 36 months, extended by 9 months Leading Institute: Central Aerohydrodynamic Institute (TsAGI) Zhukovsky, Moscow reg., Russia Contact Information: Phone: +7 (495) 5564000, fax: +7 (495) 7776332, 5564337, website: http://www.tsagi.ru Supporting Institutes: No Collaborators: AIRBUS Industrie, Blagnac, France (Hinsinger R); National Aerospace Laboratory NLR, Amsterdam, The Netherlands; ONERA, Clamart, France (Duc J M) Project Manager: KOGAN Mikhail Contact Information: ISTC Senior Project Phone: +7 (495) 5564006, fax: +7 (495) 7776332, email: mkogan@aerocentr.msk.su Manager: TOCHENY Lev Contact Information: Phone: 7 (495) 9823113, fax: 7 (499) 9783603, email: tocheny@istc.ru ISTC Website: http://www.istc.ru Background Understanding of general mechanisms of laminar flow breakdown and transition to turbulence is one of the basic problems of modern fluid dynamics. Knowledge of these mechanisms is of great importance for developing different methods for delaying laminar–turbulent transition and drag reduction. The use of laminarflow control systems and methods of turbulent drag reduction would permit one to get a significant fuel economy and to decrease the harmful effect of airplane exhausts on the Earth atmosphere. Moreover, drag reduction for perspective supersonic passenger airplanes would permit the intensity of sonic boom to be reduced. Project Objectives The main objective of the project was to conduct theoretical and experimental investigations 15
16 Aerospace Research. Volume 1 leading to friction drag reduction of civil subsonic and prospective supersonic aircraft. Description of the Work Work Plan of the Project included seven tasks. Investigations were concentrated on new laminarflow control techniques for straight and swept wings. Flow control mechanisms under investigation included vibratory and acoustic disturbances; energy supply into the boundary layer; introduction of solid and liquid particles into the flow; creation of periodic 3D flow disturbances; and local boundary layer suction. For turbulent drag reduction, the study was focused on the influence of energy supply into the turbulent boundary layer; new Large Eddy Breakup Units (LEBU) in pipelines and external turbulent boundary layer; and the influence of riblets on the aftbody drag. Obtained Results • Analysis of leading-edge flow stability and possibilities of combined laminarization of swept-wing flow using heat/mass transfer and selection of surface pressure at subsonic and supersonic velocities Numerical investigations of boundary layer stability on a high aspectratio swept wing have been carried out for various boundary conditions on the attachment line and various perturbations of parameters along the wing leading edge, namely: variable radius of leadingedge curvature along a wing span; nonuniform heating/cooling of the leading edge along the span; nonuniformly distributed gas suction; and various distributions of volumetric energy supply. It has been shown that for supersonic freestream flow, the nonuniform surface temperature distribution along the leading edge could be used for delaying the laminar–turbulent transition on the swept wing attachment line. Surface heating failed to allow crossflow stabilization. The combination of surface pressure and suction distributions proved to be an optimal method of stabilizing the boundary layer crossflow on a swept wing. Surface heating coupled with suction and particular pressure distribution was proved to be a promising solution for suppressing Tollmien– Schlichting instability in the sweptwing flow. • Experimental study of surface nonisothermicity influence on laminar–turbulent transition at subsonic velocities In the lowturbulence T36 wind tunnel (Fig. 1), the tests with a flatplate model with heated blunt nose (with the heating capacity of 3 kW/m) were carried out at freestream velocities up to 55 m/s and Reynolds number (based on the plate length) up to 6.6 · 10 6 for various heating distributions. Velocity and temperature profiles in various boundary layer cross sections as well as spatial location and statistical properties (intermittency factor and intermittency number) of transition region were measured. In all cases, the transition was determined by the evolution of Tollmien–Schlichting waves. The nose heating was found to lead to the significant growth of the transition Reynolds number even in the case of adiabatic surface. Leading edge heating eliminated the early laminar– turbulent transition caused by the roughness and unfavorable attachmentline location. The results of the tests were in agreement with the data of calculations based on the linear stability theory. • Theoretical study of thermal methods of turbulent skin-friction reduction Theoretical and numerical studies of turbulent drag reduction methods based on the local heat supply into turbulent boundary layer have shown that – viscous drag reduction efficiency (ratio of the mechanical power gain due to drag reduction to the heat supply power) in a compressible turbulent boundary layer could be increased by means of localizing heat supply regions: at a fixed heat supply power, the smaller the length of each surface heating section and the ratio of the heating sections
Page 2 and 3: INTERNATIONAL SCIENCE AND TECHNOLOG
Page 4 and 5: The International Science and Techn
Page 6 and 7: ISTC Programs The core ISTC program
Page 8 and 9: Research Projects in Aeronautics To
Page 10 and 11: Contents Aeronautics Enhancement of
Page 12 and 13: Background Laminar-turbulent transi
Page 14 and 15: spectra filling in the laminarto
Page 18 and 19: length to the distance between them
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Page 22 and 23: Project Number: #0501 Enhancement o
Page 24 and 25: Comparison of weight chara cteristi
Page 28 and 29: of TWT walls was simulated within t
Page 32 and 33: An integrated analysis was made by
Page 34 and 35: Background Development of modern tu
Page 36 and 37: Description of the Work The experim
Page 38 and 39: The aim of the project was to inves
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Page 42 and 43: Number: #0808 Enhancement of Flight
Page 44 and 45: opportunities for creating novel hy
Page 46 and 47: Unfortunately, with the computation
Page 48 and 49: Number: #0887 Enhancement of Flight
Page 50 and 51: along with a flow rate approaching
Page 52 and 53: with a conical nozzle failed to obt
Page 54 and 55: Bleed of the boundary layer on the
Page 58 and 59: Description of the Work Within the
Page 60 and 61: Obtained Results The following resu
Page 62 and 63: Project Objectives The objective of
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Project Number: #2050 Enhancement o
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Description of the Work The followi
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turbulent boundary layers and bound
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Project Number: #3085 Enhancement o
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Enhancement of Flight Performance,
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computational grid adapted to a WT
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possessing metrological parameters
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• a study of nonsymmetrical crack
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For example, freeplay can arise i
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nonlinearities and uncertainties. T
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een found. Research of interference
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verification of numerical codes des
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Background Propeller driven aviatio
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fabricated. Thereafter, a model of
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Number: #G-0916 Enhancement of Flig
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Number: #G-1600 Enhancement of Flig
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Improvement of Safety and Operation
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harmonics of the mass defect and th
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important for the HRG, are not meas
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Project Number: #0201 Improvement o
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Numerical matching at the zone boun
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The time history (for a time interv
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ISTC Project #101898 “Flight sa
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In recent years, remote sounding of
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at a distance of 1020 wingspans u
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Engineering (VORTSEC) and simplifie
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this type, a sample (aircraft) is a
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simulated. The impactorsimulator
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Decrease of Environmental Impact Pr
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The analysis of flow fields in the
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Ozone layer impact Combustion produ
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Number: #0497 Decrease of Environme
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• almost all the air and fuel (ex
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Project Number: #0627 Decrease of E
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Number: #0627.2 Decrease of Environ
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to a gasgenerator airplane in a p
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Project Objectives The objective of
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Project Number: #2249 Decrease of E
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In a new Project, this code was fur
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Obtained Results The following main
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Project Objectives The objectives o
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• for the flying test bed Tu154
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Recently, a number of papers on low
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Obtained Results 1. A model combust
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Institutes - ISTC Recipients in Aer
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List of the Project Proposals (open
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List of the Project Proposals (open
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Aerospace Research - ISTC Funded Projects 1994-2009

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