The Effect of the Boundary Layer Upon the Flow in a Conical Hypersonic Wind Tunnel Nozzle
Author : Martin Sichel
Publisher :
Page : 84 pages
File Size : 49,87 MB
Release : 1963
Category :
ISBN :
Author : Martin Sichel
Publisher :
Page : 84 pages
File Size : 49,87 MB
Release : 1963
Category :
ISBN :
Author : Ralph C. Tolle
Publisher :
Page : 274 pages
File Size : 26,44 MB
Release : 1996
Category : Hypersonic wind tunnels
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Author : Ralph A. Falanga
Publisher :
Page : 68 pages
File Size : 45,40 MB
Release : 1962
Category : Aerodynamics
ISBN :
Author :
Publisher :
Page : 704 pages
File Size : 19,48 MB
Release : 1995
Category : Aeronautics
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Author : James L. Amick
Publisher :
Page : 88 pages
File Size : 31,65 MB
Release : 1975
Category : Hypersonic wind tunnels
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Author : Max Kinslow
Publisher :
Page : 40 pages
File Size : 29,99 MB
Release : 1973
Category : Hypersonic wind tunnels
ISBN :
The potential value of controlled boundary-layer removal from the wall of a nozzle for low-density hypersonic flow was investigated in a brief experimental program. A particular objective was the achievement of sufficient control over boundary-layer thickness to enable a contoured nozzle to be operated under off-design conditions without excessive deterioration of flow uniformity. The nozzle contour was greatly influenced by boundary-layer thickness. Boundary-layer removal involved suction through perforated walls where local nozzle static pressures exceeded the pressure in the large tank which enclosed the nozzle and test section.
Author : E. R. Van Driest
Publisher :
Page : 108 pages
File Size : 47,88 MB
Release : 1961
Category : Aerodynamics, Supersonic
ISBN :
Experiments carried out in the 12-inch supersonic wind tunnel to investigate the effect of three dimensional roughness elements (spheres) on boundary-layer transition on a 10-degree (apex angle) cone without heat transfer are described. The local Mach number for these tests was 2.71. The data show clearly that the minimum (effective) size of trip required to bring transition to its lowest Reynolds number varies power of the distance from the apex of the cone to the trip. Use of available data at other Mach numbers indicates that the Mach number influence for effective tripping is taken into account by a simple expression. Some remarks concerning the roughness variation for transition on a blunt body are made. Finally, a general criterion is introduced which gives insight to the transition phenomenon and anticipates effects of external and internal disturbances, Mach number transfer.
Author : John C. Adams
Publisher :
Page : 98 pages
File Size : 43,85 MB
Release : 1972
Category : Aerodynamics, Hypersonic
ISBN :
An analytical approach toward numerical calculation of the three-dimensional turbulent boundary layer on a sharp cone at incidence under supersonic and hypersonic flow conditions is presented. The theoretical model is based on implicit finite-difference integration of the governing three-dimensional turbulent boundary-layer equations in conjunction with a three-dimensional scalar eddy-viscosity model of turbulence. Comparison is made of present theory with detailed experimental measurements of the three-dimensional turbulent boundary-layer structure (velocity and temperature profiles), the surface streamline direction (obtained via an oil-flow technique) and surface heat-transfer rate.
Author : National Aeronautics and Space Adm Nasa
Publisher :
Page : 134 pages
File Size : 44,42 MB
Release : 2018-11-18
Category :
ISBN : 9781731266217
An experimental investigation of the effects of angle of attack on hypersonic boundary-layer stability on a flared-cone model was conducted in the low-disturbance Mach-6 Nozzle-Test Chamber Facility at NASA Langley Research Center. This unique facility provided a 'quiet' flow test environment which is well suited for stability experiments because the low levels of freestream 'noise' minimize artificial stimulation of flow-disturbance growth. Surface pressure and temperature measurements documented the adverse-pressure gradient and transition-onset location. Hot-wire anemometry diagnostics were applied to identify the instability mechanisms which lead to transition. In addition, the mean flow over the flared-cone geometry was modeled by laminar Navier-Stokes computations. Results show that the boundary layer becomes more stable on the windward ray and less stable on the leeward ray relative to the zero-degree angle-of-attack case. The second-mode instability dominates the transition process at a zero-degree angle of attack, however, on the windward ray at an angle of attack this mode was completely stabilized. The less-dominant first-mode instability was slightly destabilized on the windward ray. Non-linear mechanisms such as saturation and harmonic generation are identified from the flow-disturbance bispectra. Doggett, Glen P. and Chokani, Ndaona Langley Research Center ANGLE OF ATTACK; AERODYNAMIC NOISE; ZERO ANGLE OF ATTACK; BOUNDARY LAYER STABILITY; HYPERSONIC SPEED; NAVIER-STOKES EQUATION; HYPERSONICS; AERODYNAMIC STABILITY; HYPERSONIC BOUNDARY LAYER; WIND TUNNELS; VELOCITY MEASUREMENT; TEST CHAMBERS; LOW NOISE...
Author : National Aeronautics and Space Administration (NASA)
Publisher : Createspace Independent Publishing Platform
Page : 232 pages
File Size : 24,94 MB
Release : 2018-07-25
Category :
ISBN : 9781724242556
Hypersonic boundary layer measurements over a flared cone were conducted in a Mach 6 quiet wind tunnel at a freestream unit Reynolds number of 2.82 million/ft. This Reynolds number provided laminar-to-transitional flow over the cone model in a low-disturbance environment. Four interchangeable nose-tips, including a sharp-tip, were tested. Point measurements with a single hot-wire using a novel constant voltage anemometer were used to measure the boundary layer disturbances. Surface temperature and schlieren measurements were also conducted to characterize the transitional state of the boundary layer and to identify instability modes. Results suggest that second mode disturbances were the most unstable and scaled with the boundary layer thickness. The second mode integrated growth rates compared well with linear stability theory in the linear stability regime. The second mode is responsible for transition onset despite the existence of a second mode subharmonic. The subharmonic disturbance wavelength also scales with the boundary layer thickness. Furthermore, the existence of higher harmonics of the fundamental suggests that nonlinear disturbances are not associated with 'high' free stream disturbance levels. Nose-tip radii greater than 2.7% of the base radius completely stabilized the second mode. Lachowicz, Jason T. and Chokani, Ndaona Langley Research Center NASA-CR-198272, NAS 1.26:198272 NCC1-183; RTOP-505-59-50-02...