Author: Albert L. Braslow
Publisher:
ISBN:
Category : Numerical analysis
Languages : en
Pages : 44
Book Description
Effect of Distributed Three-dimensional Roughness and Surface Cooling on Boundary-layer Transition and Lateral Spread of Turbulence at Supersonic Speeds
Author: Albert L. Braslow
Publisher:
ISBN:
Category : Numerical analysis
Languages : en
Pages : 44
Book Description
Publisher:
ISBN:
Category : Numerical analysis
Languages : en
Pages : 44
Book Description
Investigation by Schlieren Technique of Methods of Fixing Fully Turbulent Flow on Models at Supersonic Speeds
Author: Mary W. Jackson
Publisher:
ISBN:
Category : Reynolds number
Languages : en
Pages : 20
Book Description
Publisher:
ISBN:
Category : Reynolds number
Languages : en
Pages : 20
Book Description
NASA Reference Publication
Author:
Publisher:
ISBN:
Category : Astronautics
Languages : en
Pages : 984
Book Description
Publisher:
ISBN:
Category : Astronautics
Languages : en
Pages : 984
Book Description
Free Flight Hypersonic Heat Transfer and Boundary Layer Transition Studies
Author: James E. Brunk
Publisher:
ISBN:
Category : Aerodynamic heating
Languages : en
Pages : 168
Book Description
Two HTV-1 Hypersonic Test Vehicles, Rounds A-40 and A-41, were flown at Holloman AFB in October 1959, with blunted and sharp 20 degree half angle nose cones, respectively. Round A-40 also incorporated nose cone incidence and a pitch disturber rocket. A maximum flight velociety of 5800 feet per second was attained, corresponding to a local shap cone Mach number and unit Reynolds number of 3.4 and 50 x 10(6) per foot respectively. Fligh dynamics data for the second stage of Round A-40 were obtained from analyses of the vector angle of attack history. The measured maximum trim angle of attack (1.5 degrees) agreed closely with the predicted trim based on an elastic structure and a nose cone incidence of 0.36 degrees. Surface temperatures and aerodynamic heating rates were obtained for one station and three radial positions on the conical portion of the blunted nose cone (Round A-40) and at 3 stations on each of the two longitudinal rays on the sharp cone (Round A-41). In addition, the temperature and heating rates were determined on the cylindrical portion of the Round A-41 payload and on the base of on Stage II fin for both vehicles. The maximum heating rate for the sharp cone was about 30 percent greater for the blunt cone as a result of higher local Mach numbers and Reynolds numbers on the sharp cone. Correlation of the blunted cone circumferential heating rates with the measured angle of attack showed that only a small increase in heating rate (less than about 5 percent increase from the zero angle of attack heating rate) occurs on the windward ray for turbulent heating conditions. The measured decrease in Stanton mumber with increasing Reynolds number (running length) for the sharp cone was found to be in close agreement with turbulent flow theory. Boundary layer transition reversal from turbulent to laminar flow was experienced on both the sharp and blunted tip cones. Transition reversal for the sharp cone, which had almost twice the local Mach number of the blunted cone, was found to occur at an enthalpy ratio, hw/hr, 30 percent greater than for the blunted cone. For both cones turbulent flow occurred within the Mach number and enthalpy region for complete stability of two dimensional disturbance as defined by Dunn and Lin. The possible effects of surface roughness in producing the observed transition reversal are discussed.
Publisher:
ISBN:
Category : Aerodynamic heating
Languages : en
Pages : 168
Book Description
Two HTV-1 Hypersonic Test Vehicles, Rounds A-40 and A-41, were flown at Holloman AFB in October 1959, with blunted and sharp 20 degree half angle nose cones, respectively. Round A-40 also incorporated nose cone incidence and a pitch disturber rocket. A maximum flight velociety of 5800 feet per second was attained, corresponding to a local shap cone Mach number and unit Reynolds number of 3.4 and 50 x 10(6) per foot respectively. Fligh dynamics data for the second stage of Round A-40 were obtained from analyses of the vector angle of attack history. The measured maximum trim angle of attack (1.5 degrees) agreed closely with the predicted trim based on an elastic structure and a nose cone incidence of 0.36 degrees. Surface temperatures and aerodynamic heating rates were obtained for one station and three radial positions on the conical portion of the blunted nose cone (Round A-40) and at 3 stations on each of the two longitudinal rays on the sharp cone (Round A-41). In addition, the temperature and heating rates were determined on the cylindrical portion of the Round A-41 payload and on the base of on Stage II fin for both vehicles. The maximum heating rate for the sharp cone was about 30 percent greater for the blunt cone as a result of higher local Mach numbers and Reynolds numbers on the sharp cone. Correlation of the blunted cone circumferential heating rates with the measured angle of attack showed that only a small increase in heating rate (less than about 5 percent increase from the zero angle of attack heating rate) occurs on the windward ray for turbulent heating conditions. The measured decrease in Stanton mumber with increasing Reynolds number (running length) for the sharp cone was found to be in close agreement with turbulent flow theory. Boundary layer transition reversal from turbulent to laminar flow was experienced on both the sharp and blunted tip cones. Transition reversal for the sharp cone, which had almost twice the local Mach number of the blunted cone, was found to occur at an enthalpy ratio, hw/hr, 30 percent greater than for the blunted cone. For both cones turbulent flow occurred within the Mach number and enthalpy region for complete stability of two dimensional disturbance as defined by Dunn and Lin. The possible effects of surface roughness in producing the observed transition reversal are discussed.
The Effect of Pressure Gradients on Transition Zone Length in Hypersonic Boundary Layers
Author: Roger L. Kimmel
Publisher:
ISBN:
Category : Aerodynamics, Hypersonic
Languages : en
Pages : 46
Book Description
Boundary layer transition was measured in zero, favorable, and adverse pressure gradients at Mach 8 using heat transfer. Models consisted of 7 degrees half angle forecones 0.4826 m long, followed by flared or ogive aft bodies 0.5334 m long. The flares and ogives produced constant pressure gradients. For the cases examined, favorable pressure gradients delay transition and adverse pressure gradients promote transition, but transition zone lengths are shorter in favorable pressure gradient. Results of the effect of adverse pressure gradient on transition zone lengths were inconclusive.
Publisher:
ISBN:
Category : Aerodynamics, Hypersonic
Languages : en
Pages : 46
Book Description
Boundary layer transition was measured in zero, favorable, and adverse pressure gradients at Mach 8 using heat transfer. Models consisted of 7 degrees half angle forecones 0.4826 m long, followed by flared or ogive aft bodies 0.5334 m long. The flares and ogives produced constant pressure gradients. For the cases examined, favorable pressure gradients delay transition and adverse pressure gradients promote transition, but transition zone lengths are shorter in favorable pressure gradient. Results of the effect of adverse pressure gradient on transition zone lengths were inconclusive.
Index to NASA Technical Publications
Author: United States. National Aeronautics and Space Administration
Publisher:
ISBN:
Category :
Languages : en
Pages : 300
Book Description
Publisher:
ISBN:
Category :
Languages : en
Pages : 300
Book Description
A Selected Listing of NASA Scientific and Technical Reports for ...
Author:
Publisher:
ISBN:
Category : Aeronautics
Languages : en
Pages : 296
Book Description
Publisher:
ISBN:
Category : Aeronautics
Languages : en
Pages : 296
Book Description
Index of NASA Technical Publications
Author:
Publisher:
ISBN:
Category : Aeronautics
Languages : en
Pages : 494
Book Description
Publisher:
ISBN:
Category : Aeronautics
Languages : en
Pages : 494
Book Description
Index of NACA Technical Publications
Author: United States. National Advisory Committee for Aeronautics
Publisher:
ISBN:
Category : Aeronautics
Languages : en
Pages : 860
Book Description
Publisher:
ISBN:
Category : Aeronautics
Languages : en
Pages : 860
Book Description
Index of N A S A Technical Publications
Author: United States. National Aeronautics and Space Administration
Publisher:
ISBN:
Category :
Languages : en
Pages : 498
Book Description
Publisher:
ISBN:
Category :
Languages : en
Pages : 498
Book Description