Author: Joseph H. Kemp
Publisher:
ISBN:
Category : Aerodynamics, Supersonic
Languages : en
Pages : 7
Book Description
Preliminary Results from an Experimental Investigation of Nozzle Wall Boundary Layers at Mach Numbers Ranging from 27 to 47
Experimental Study of Nozzle Wall Boundary Layers at Mach Numbers 20 to 47
Author: Joseph H. Kemp
Publisher:
ISBN:
Category : Aerodynamics, Hypersonic
Languages : en
Pages : 116
Book Description
The nozzle wall boundary layer of an M-50 helium tunnel was investigated with pitot pressure, total temperature, skin friction, and wall heat transfer measurements at five stations and hot wire measurements at two stations. The results indicated that the boundary layer was turbulent with a thick viscous sublayer. Pressure gradients were observed across the boundary layer; the effect of these gradients on the equations of motion are discussed. The direct skin friction measurements were higher than expected from empirical predictions; the Reynolds analogy factors however were lower than expected. Hot wire measurements indicated mass flow fluctuations as large as 80 percent of the local mean mass flow at the edge of the viscous sublayer with a maximum value relative to the edge mass flow of about 15 percent at gamma about equal to 0.8.
Publisher:
ISBN:
Category : Aerodynamics, Hypersonic
Languages : en
Pages : 116
Book Description
The nozzle wall boundary layer of an M-50 helium tunnel was investigated with pitot pressure, total temperature, skin friction, and wall heat transfer measurements at five stations and hot wire measurements at two stations. The results indicated that the boundary layer was turbulent with a thick viscous sublayer. Pressure gradients were observed across the boundary layer; the effect of these gradients on the equations of motion are discussed. The direct skin friction measurements were higher than expected from empirical predictions; the Reynolds analogy factors however were lower than expected. Hot wire measurements indicated mass flow fluctuations as large as 80 percent of the local mean mass flow at the edge of the viscous sublayer with a maximum value relative to the edge mass flow of about 15 percent at gamma about equal to 0.8.
NASA Technical Note
Author:
Publisher:
ISBN:
Category :
Languages : en
Pages : 460
Book Description
Publisher:
ISBN:
Category :
Languages : en
Pages : 460
Book Description
Research Review
Author:
Publisher:
ISBN:
Category : Research
Languages : en
Pages : 324
Book Description
Publisher:
ISBN:
Category : Research
Languages : en
Pages : 324
Book Description
Research Review
Author: United States. Air Force. Office of Aerospace Research
Publisher:
ISBN:
Category : Astronautics
Languages : en
Pages : 138
Book Description
Publisher:
ISBN:
Category : Astronautics
Languages : en
Pages : 138
Book Description
NASA Scientific and Technical Reports
Author: United States. National Aeronautics and Space Administration Scientific and Technical Information Division
Publisher:
ISBN:
Category : Aeronautics
Languages : en
Pages : 966
Book Description
Publisher:
ISBN:
Category : Aeronautics
Languages : en
Pages : 966
Book Description
NASA Scientific and Technical Reports and Publications for 1969 - A Selected Listing
Author: United States. National Aeronautics and Space Administration. Scientific and Technical Information Division
Publisher:
ISBN:
Category : Science
Languages : en
Pages : 956
Book Description
Publisher:
ISBN:
Category : Science
Languages : en
Pages : 956
Book Description
A Selected Listing of NASA Scientific and Technical Reports
Author: United States. National Aeronautics and Space Administration. Scientific and Technical Information Division
Publisher:
ISBN:
Category : Aeronautics
Languages : en
Pages : 962
Book Description
Publisher:
ISBN:
Category : Aeronautics
Languages : en
Pages : 962
Book Description
An Experimental Investigation of Nozzle-exit Boundary Layers of Highly Heated Free Jets
Author: Jan Lepicovsky
Publisher:
ISBN:
Category : Boundary layer
Languages : en
Pages : 0
Book Description
An experimental investigation of the effects of nozzle operating conditions on the development of nozzle-exit boundary layers of highly heated air free jets is reported in this paper. The total pressure measurements in the nozzle-exit boundary layer were obtained at a range of jet Mach numbers from 0.1 to 0.97 and jet total temperatures up to 900 K. The analysis of results shows that the nozzle-exit laminar boundary-layer development depends only on the nozzle-exit Reynolds number. For the nozzle-exit turbulent boundary layer, however, it appears that the effects of the jet total temperature on the boundary-layer integral characteristics are independent from the effect of the nozzle-exit Reynolds number. This surprising finding has not yet been reported. Further, laminar boundary-layer profiles were compared with the Pohlhausen solution for a flat-wall converging channel and an acceptable agreement was found only for low Reynolds numbers. For turbulent boundary layers, the dependence of the shape factor on relative Mach numbers at a distance of one momentum thickness from the nozzle wall resembles Spence's prediction. Finally, the calculated total pressure loss coefficient was found to depend on the nozzle-exit Reynolds number for the laminar nozzle-exit boundary layer, while for the turbulent exit boundary layer this coefficient appears to be constant.
Publisher:
ISBN:
Category : Boundary layer
Languages : en
Pages : 0
Book Description
An experimental investigation of the effects of nozzle operating conditions on the development of nozzle-exit boundary layers of highly heated air free jets is reported in this paper. The total pressure measurements in the nozzle-exit boundary layer were obtained at a range of jet Mach numbers from 0.1 to 0.97 and jet total temperatures up to 900 K. The analysis of results shows that the nozzle-exit laminar boundary-layer development depends only on the nozzle-exit Reynolds number. For the nozzle-exit turbulent boundary layer, however, it appears that the effects of the jet total temperature on the boundary-layer integral characteristics are independent from the effect of the nozzle-exit Reynolds number. This surprising finding has not yet been reported. Further, laminar boundary-layer profiles were compared with the Pohlhausen solution for a flat-wall converging channel and an acceptable agreement was found only for low Reynolds numbers. For turbulent boundary layers, the dependence of the shape factor on relative Mach numbers at a distance of one momentum thickness from the nozzle wall resembles Spence's prediction. Finally, the calculated total pressure loss coefficient was found to depend on the nozzle-exit Reynolds number for the laminar nozzle-exit boundary layer, while for the turbulent exit boundary layer this coefficient appears to be constant.
Analytic Methods in Aircraft Aerodynamics
Author:
Publisher:
ISBN:
Category : Aerodynamics
Languages : en
Pages : 758
Book Description
Publisher:
ISBN:
Category : Aerodynamics
Languages : en
Pages : 758
Book Description