Characteristics of turbulent spots and the transition zone under the influence of an adverse pressure gradient within a free piston shock tunnel

2021 ◽  
Author(s):  
◽  
Isaac Convery-Brien
Keyword(s):  
Pressure Gradient ◽  
Transition Zone ◽  
Adverse Pressure Gradient ◽  
Shock Tunnel ◽  
Free Piston ◽  
Turbulent Spots

scholarly journals Investigation of the Calmed Region Behind a Turbulent Spot

1996 ◽  
Author(s):  
J. P. Gostelow ◽  
G. J. Walker ◽  
W. J. Solomon ◽  
G. Hong ◽  
N. Melwani
Keyword(s):  
Boundary Layer ◽  
Pressure Gradient ◽  
Axial Flow ◽  
Adverse Pressure Gradient ◽  
Turbulent Spot ◽  
Boundary Layer Flows ◽  
Turbulent Spots ◽  
Turbulent Layer ◽  
Controlled Diffusion ◽  
Flow Compressor

Measurements are presented of the calmed region behind triggered wave packets and turbulent spots under a controlled diffusion adverse pressure gradient in a wind tunnel. Similar measurements are also presented from the stator blades of an axial flow compressor, where turbulent spots are induced by the passing of rotor wakes. The purpose is to gain an appreciation of turbulent spot behavior under a strong adverse pressure gradient as a foundation for the more accurate modeling of spots and their environment in predictions of transitional boundary layer flows. Under an adverse pressure gradient the calmed region behind the spot is extensive; its interaction with the surrounding turbulent layer is complex and is dependent on whether the surrounding natural boundary layer is laminar or turbulent. Some insights are gleaned concerning the behavior of the calmed region which will subsequently be used in attempts to model the calmed region. Although these fundamental investigations of the calmed region have been extensive much remains to be understood.

Turbulent spots in boundary layers in a free-piston shock-tunnel flow

Shock Waves ◽  
1996 ◽  
Vol 6 (6) ◽  
pp. 337-343 ◽  
Author(s):  
D. J. Mee ◽  
C. P. Goyne
Keyword(s):  
Boundary Layers ◽  
Shock Tunnel ◽  
Free Piston ◽  
Turbulent Spots

Investigation of the Calmed Region Behind a Turbulent Spot

1997 ◽  
Vol 119 (4) ◽  
pp. 802-809 ◽  
Author(s):  
J. P. Gostelow ◽  
G. J. Walker ◽  
W. J. Solomon ◽  
G. Hong ◽  
N. Melwani
Keyword(s):  
Boundary Layer ◽  
Pressure Gradient ◽  
Axial Flow ◽  
Adverse Pressure Gradient ◽  
Turbulent Spot ◽  
Boundary Layer Flows ◽  
Turbulent Spots ◽  
Controlled Diffusion ◽  
Transitional Boundary Layer ◽  
Flow Compressor

Measurements are presented of the calmed region behind triggered wave packets and turbulent spots under a controlled diffusion adverse pressure gradient in a wind tunnel. Similar measurements are also presented from the stator blades of an axial flow compressor, where turbulent spots are induced by the passing of rotor wakes. The purpose is to gain an appreciation of turbulent spot behavior under a strong adverse pressure gradient as a foundation for the more accurate modeling of spots and their environment in predictions of transitional boundary layer flows. Under an adverse pressure gradient the calmed region behind the spot is extensive; its interaction with the surrounding boundary layer is complex and is dependent on whether the surrounding natural boundary layer is laminar or turbulent. Some insights are gleaned concerning the behavior of the calmed region, which will subsequently be used in attempts to model the calmed region. Although these fundamental investigations of the calmed region have been extensive, much remains to be understood.

Turbulent spots in boundary layers in a free-piston shock-tunnel flow

Shock Waves ◽  
1996 ◽  
Vol 6 (6) ◽  
pp. 337-1
Author(s):  
D.J. Mee ◽  
C.P. Goyne
Keyword(s):  
Boundary Layers ◽  
Shock Tunnel ◽  
Free Piston ◽  
Turbulent Spots

The Effect of Pressure Gradients on Transition Zone Length in Hypersonic Boundary Layers

1997 ◽  
Vol 119 (1) ◽  
pp. 36-41 ◽  
Author(s):  
R. L. Kimmel
Keyword(s):  
Pressure Gradient ◽  
Transition Zone ◽  
Adverse Pressure Gradient ◽  
Boundary Layer Transition ◽  
Pressure Gradients ◽  
Layer Transition ◽  
Zone Length ◽  
Hypersonic Boundary Layers ◽  
Favorable Pressure Gradient ◽  
Half Angle

Boundary layer transition was measured in zero, favorable, and adverse pressure gradients at Mach 8 using heat transfer. Models consisted of 7° 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.

Effect of Adverse Pressure Gradient on Film Cooling Effectiveness

AIAA Journal ◽  
1974 ◽  
Vol 12 (5) ◽  
pp. 708-709 ◽  
Author(s):  
V. ZAKKAY ◽  
CHI R. WANG ◽  
M. MIYAZAWA
Keyword(s):  
Pressure Gradient ◽  
Film Cooling ◽  
Adverse Pressure Gradient ◽  
Cooling Effectiveness ◽  
Film Cooling Effectiveness

Free-flight measurement technique in the free-piston high-enthalpy shock tunnel

2014 ◽  
Vol 85 (4) ◽  
pp. 045112 ◽  
Author(s):  
H. Tanno ◽  
T. Komuro ◽  
K. Sato ◽  
K. Fujita ◽  
S. J. Laurence
Keyword(s):  
Measurement Technique ◽  
Shock Tunnel ◽  
Free Flight ◽  
Free Piston ◽  
High Enthalpy ◽  
Flight Measurement ◽  
High Enthalpy Shock Tunnel
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