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Experimental study of compressible boundary layer on a cone at angles of attack 被引量:2
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作者 A.Maslov D.Bountin +3 位作者 A.Shiplyuk A.Sidorenko Q.Shen Z.Bi 《Acta Mechanica Sinica》 SCIE EI CAS CSCD 2009年第3期325-333,共9页
Experimental study was conducted for boundarylayers on a sharp 5° half-angle cone of 400mm length at angles of attack. The model was tested in the T-326 hypersonic wind tunnel (ITAM) at freestream Mach number M... Experimental study was conducted for boundarylayers on a sharp 5° half-angle cone of 400mm length at angles of attack. The model was tested in the T-326 hypersonic wind tunnel (ITAM) at freestream Mach number M = 5.95. Mean and fluctuation wall characteristics of the boundary layer are measured at 0°, 2°, 3° and 4° angles of attack for different stagnation pressures. Pulsation measurements are carried out by means of ALTP sensor. Pressure and temperature distributions along the model are obtained, and transition beginning and end locations have been found. Boundary layer stabilization with the increase of angle of attack and the decrease of stagnation pressure is observed. High frequency pulsations inherent to hypersonic boundary layer (second mode) have been detected. 展开更多
关键词 compressible boundary layer Transition Experimental study
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Analytical solutions to a compressible boundary layer problem with heat transfer 被引量:1
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作者 LiancunZheng XinxinZhang JichengHe 《Journal of University of Science and Technology Beijing》 CSCD 2004年第2期120-122,共3页
The problem of momentum and heat transfer in a compressible boundary layerbehind a thin expansion wave was solved by the application of the similarity transformation and theshooting technique. Utilizing the analytical... The problem of momentum and heat transfer in a compressible boundary layerbehind a thin expansion wave was solved by the application of the similarity transformation and theshooting technique. Utilizing the analytical expression of a two-point boundary value problem formomentum transfer, the energy boundary layer solution was represented as a function of thedimensionless velocity, and as the parameters of the Prandtl number, the velocity ratio, and thetemperature ratio. 展开更多
关键词 compressible boundary layer momentum and heat transfer analytical solution
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Mathematical Formulation of Bubble Formation after Compressible Boundary Layer Separation: Preliminary Numerical Results
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作者 Michail A. Xenos 《Open Journal of Fluid Dynamics》 CAS 2022年第4期304-320,共17页
Laminar boundary layer (BL), under adverse pressure gradient, can separate. The separated shear layer reattaches to form a laminar separation bubble. Such bubbles are usually observed on gas turbine blades, on low Rey... Laminar boundary layer (BL), under adverse pressure gradient, can separate. The separated shear layer reattaches to form a laminar separation bubble. Such bubbles are usually observed on gas turbine blades, on low Reynolds number wings and close to the leading edges of airfoils. Presence of bubbles has a weakening effect on the performance of a fluid device. The understanding of the prevailing mechanism of the separation bubble and ways to control it are essential for the efficient design of these devices. This is due to the significance of drag reduction in these various aerodynamic devices, such as gas turbines, re-entry space vehicles and airfoils. This study introduces a two-dimensional mathematical formulation of bubble formation after flow separation. The laminar BL equations with appropriate boundary conditions are dimensionalized using the Falkner-Skan transformation. Additionally, using the Keller-box method, the nonlinear system of partial differential equations (PDEs) is numerically solved. This study presents preliminary numerical results of bubble formation in low Mach numbers. These results reveal that after separation, a laminar bubble is formed in all studied cases, for Mach numbers, M = 0.2, 0.33 and 1.0. The flow after separation reverses close to the wall and finally reattaches downstream, in a new location. As the Mach number increases, this effect is more intense. After reattachment, the BL is again established in a lower energy level and the velocity field is substantially reduced, for all cases. 展开更多
关键词 Laminar Separation Bubble compressible boundary layer Fluid Mechanics Computational Fluid Dynamics
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ANALYSIS OF THE SECONDARY STABILITY OF COMPRESSIBLE BOUNDARY LAYER FLOWS OVER A TWO-DIMENSIONAL PLATE
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作者 范绪箕 楼卓时 《Applied Mathematics and Mechanics(English Edition)》 SCIE EI 1999年第5期51-56,共6页
This paper used the Floquet's three _dimensional linear stability theory in the analysis of two_dimensional compress ible boundary layer, a set of stability equations is constructed, the effect of three dimensio... This paper used the Floquet's three _dimensional linear stability theory in the analysis of two_dimensional compress ible boundary layer, a set of stability equations is constructed, the effect of three dimensional linear small perturbation on the two_dimensional compressible boundary layer transition is studied, and the effect of coming flow Ma number on growth and development of the subharmonics is calculated. It can be seen from t he calculations, the effect caused by the interaction of two_dimensional and thr ee_dimensional perturbation waves on the development of two_dimensional compress ible laminar boundary layer. 展开更多
关键词 compressible boundary layer secondary instability PERTURBATION
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A NUMERICAL STUDY FOR SMALL AMPLITUDE T_S WAVES IN A SUPERSONIC BOUNDARY LAYER 被引量:1
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作者 袁湘江 周恒 《Applied Mathematics and Mechanics(English Edition)》 SCIE EI 2000年第12期1341-1344,共4页
The propagation of the disturbance waves in a boundary layer at Mach number = 4.5 is studied by direct numerical simulation (DNS), using NND scheme, and different amplitudes A = 0.01, 0.001, 0.000 1 of the disturbance... The propagation of the disturbance waves in a boundary layer at Mach number = 4.5 is studied by direct numerical simulation (DNS), using NND scheme, and different amplitudes A = 0.01, 0.001, 0.000 1 of the disturbance have been assumed. The numerical result shows that there might be shocklets induced in the boundary layer, even when the amplitude of disturbance wave is still small. 展开更多
关键词 direct numerical simulation SHOCKLET compressible boundary layer
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Sidewall influence of varying free stream Mach number in ramp induced shock wave boundary layer interactions
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作者 Raja Mangalagiri Satya P.Jammy 《Theoretical & Applied Mechanics Letters》 CAS 2024年第4期298-305,共8页
This study investigates the three-dimensional(3D)effects introduced by the end walls for an aspect ratio of1 in ramp-induced shock wave boundary layer interactions.The simulations are performed using a symmetry bounda... This study investigates the three-dimensional(3D)effects introduced by the end walls for an aspect ratio of1 in ramp-induced shock wave boundary layer interactions.The simulations are performed using a symmetry boundary condition in the spanwise direction at free-stream Mach numbers in 3D.The simulations are performed using an in-house compressible supersonic solver“Open SBLIFVM”.Two free stream Mach numbers 2.5,and3 are used in the current work,and the simulated results are compared with the aspect ratio 1 simulations by Mangalagiri and Jammy.The inflow is initialized with a similarity solution;its Reynolds number based on the boundary layer thickness is adjusted such that the Reynolds number at the start of the ramp is kept at 3×10^(5)for all simulations.From the results,it is evident that the introduction of sidewalls resulted in a shorter centerline separation length when compared with the two-dimensional(2D)simulations.This contradicts the results at Mach 2 by Mangalgiri and Jammy where the vortex observed at Mach 2 in the central separation region disappeared with increasing free-stream Mach number.Additionally,the topology of interaction shifted from owl-like separation of the second kind to the first kind when the freestream Mach number increased from2 to 2.5.It can be concluded that the interaction topology is crucial to the increase or decrease of the central separation length when compared to 2D simulations. 展开更多
关键词 Shock boundary layer interaction Separation compressible boundary layers GPGPU simulations RSWBLI
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Compressible Turbulent Boundary Layers on a Strongly Heated Wall
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作者 Doug-Bong LEE Franck SOCHELEAU Roger LEBLANC 《Journal of Thermal Science》 SCIE EI CAS CSCD 1993年第3期213-227,共15页
This paper concerns the theoretical and experimental modelling of the flat wall,highly heated,compressible turbulent boundary layer.Its final objective is to develop a numerical Navier-Stokes solver and to conclude on... This paper concerns the theoretical and experimental modelling of the flat wall,highly heated,compressible turbulent boundary layer.Its final objective is to develop a numerical Navier-Stokes solver and to conclude on its capability to correctly represent complex aerothermic viscous flows near the wall.The paper presents a constructed numerical method with particular attention given to the turbulence modelling at low Reynolds number and comparisons with supersonic and transonic experimental data.For the transonic experiment,very high wall temperature(Tw=1100K)is realized.The method of this difficult experimental set up is discussed.The comparison between experimental and computational data conducts to the first conclusion and gives some indications for the future work. 展开更多
关键词 compressible turbulent boundary layer transonic wind tunnel strong wall heating low Reynolds number k model
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Wind Wave Growth
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作者 Kern E. Kenyon 《Natural Science》 2021年第5期137-139,共3页
A recent formula for the lift force on a low speed wing of circular arc cross-section [<span style="font-family:Verdana;"><span style="font-family:Verdana;"><b><span style=&quo... A recent formula for the lift force on a low speed wing of circular arc cross-section [<span style="font-family:Verdana;"><span style="font-family:Verdana;"><b><span style="font-family:Verdana;"><a href="#ref1">1</a></span></b></span></span><span><span></span></span><span></span><span style="font-family:Verdana;"><span style="font-family:Verdana;"><span style="font-family:Verdana;">] is adapted to the upward pressure force on the crests of a surface gravity wave propagating in the wind. In both cases</span></span></span><span style="font-family:Verdana;"><span style="font-family:Verdana;"><span style="font-family:Verdana;">,</span></span></span><span style="font-family:Verdana;"><span style="font-family:Verdana;"><span style="font-family:Verdana;"> the main feature is the utilization of the air’s compressibility. At and near a wave crest</span></span></span><span style="font-family:Verdana;"><span style="font-family:Verdana;"><span style="font-family:Verdana;">,</span></span></span><span style="font-family:Verdana;"><span style="font-family:Verdana;"><span style="font-family:Verdana;"> it is predicted that the air density is increased over the ambient value and that the air density decreases inversely as the square of the upward distance from the radius of curvature of the crest. As a consequence</span></span></span><span style="font-family:Verdana;"><span style="font-family:Verdana;"><span style="font-family:Verdana;">,</span></span></span><span><span><span style="font-family:;" "=""><span style="font-family:Verdana;"> the air pressure also decreases upward inversely as the square of the same distance. Therefore, an upward pressure force on each crest occurs which presumably will make the crests grow. Growth rates are largest for small </span><span style="font-family:Verdana;">wavelengths and large mean slopes of the wave surface. Contrary winds should produce </span><span style="font-family:Verdana;">wave growth (not damping) as well as no wind at all.</span></span></span></span> 展开更多
关键词 Wind Wave Growth Compressed Air boundary layer
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β-distribution for Reynolds stress and turbulent heat flux in relaxation turbulent boundary layer of compression ramp
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作者 YanChao Hu WeiTao Bi +1 位作者 ShiYao Li ZhenSu She 《Science China(Physics,Mechanics & Astronomy)》 SCIE EI CAS CSCD 2017年第12期36-44,共9页
A challenge in the study of turbulent boundary layers(TBLs) is to understand the non-equilibrium relaxation process after separation and reattachment due to shock-wave/boundary-layer interaction. The classical boundar... A challenge in the study of turbulent boundary layers(TBLs) is to understand the non-equilibrium relaxation process after separation and reattachment due to shock-wave/boundary-layer interaction. The classical boundary layer theory cannot deal with the strong adverse pressure gradient, and hence, the computational modeling of this process remains inaccurate. Here, we report the direct numerical simulation results of the relaxation TBL behind a compression ramp, which reveal the presence of intense large-scale eddies, with significantly enhanced Reynolds stress and turbulent heat flux. A crucial finding is that the wall-normal profiles of the excess Reynolds stress and turbulent heat flux obey a β-distribution, which is a product of two power laws with respect to the wall-normal distances from the wall and from the boundary layer edge. In addition, the streamwise decays of the excess Reynolds stress and turbulent heat flux also exhibit power laws with respect to the streamwise distance from the corner of the compression ramp. These results suggest that the relaxation TBL obeys the dilation symmetry, which is a specific form of self-organization in this complex non-equilibrium flow. The β-distribution yields important hints for the development of a turbulence model. 展开更多
关键词 compression ramp relaxation turbulent boundary layer Reynolds stress β-distribution symmetry
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