Free-Stream Turbulence Effects on Convex-Curved Turbulent Boundary Layers

You, Seungkwon; Simon, Terrence W.; Kim, J.

doi:10.1115/1.3250660

Cited by 4 publications

(2 citation statements)

References 0 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…Several researches (Simonich and Moffat, 1984;Crane and Sabzvari, 1989;You et al, 1989, andSchobeiri et al, 1991) (1993) proved that the Inconel 600 foil was a more uniform heater sheet by determining that the error for the heat transfer coefficient was approximately +/-3.7%. Therefore, the heater sheet in this investigation is Inconel 600.…”

Section: Heat Transfer Measurementsmentioning

confidence: 99%

Periodic Unsteady Flow Aerodynamics and Heat Transfer: Studies on a Curved Surface, Combined Part I and II

Schobeiri

Wright

Chakka

2000

International Journal of Rotating Machinery

View full text Add to dashboard Cite

Aerodynamic and heat transfer investigations were done on a constant curvature curved plate in a subsonic wind tunnel facility for various wake passing frequencies and zero pressure gradient conditions. Steady and unsteady boundary layer transition measurements were taken on the concave surface of the curved plate at different wake passing frequencies where a rotating squirrel-cage generated the unsteady wake flow. The data were analyzed using timeaveraged and ensemble-averaged techniques to provide insight into the growth of the boundary layer and transition. Ensemble-averaged turbulence intensity contours in the temporal spatial domain showed that transition was induced for increasing wake passing frequency and structure. The local heat transfer coefficient distribution for the concave and convex surface was determined at those wake passing frequencies using a liquid crystal heat transfer measurement technique. Detailed aerodynamic and heat transfer investigations showed that higher wake passing frequency caused transition to occur earlier on the concave surface. Local Stanton numbers were also calculated on the concave surface and compared with Stanton numbers predicted using a differential boundary layer and heat transfer calculation method. On the convex side, no effect of wake passing frequency on heat transfer was observed due to a separation bubble that induced transition.

show abstract

Section: Heat Transfer Measurementsmentioning

confidence: 99%

Periodic Unsteady Flow Aerodynamics and Heat Transfer: Studies on a Curved Surface, Combined Part I and II

Schobeiri

Wright

Chakka

2000

International Journal of Rotating Machinery

View full text Add to dashboard Cite

show abstract

“…Greek Symbols surfaces. You et al (1986) studied the effects of two levels of free-stream turbulence intensity (0.65%4.85%) on a heated turbulent boundary layer /3…”

mentioning

confidence: 99%

Effects of Free-Stream Turbulence Intensity on a Boundary Layer Recovering From Concave Curvature Effects

Kestoras

Simon

1993

Volume 2: Combustion and Fuels; Oil and Gas Applications; Cycle Innovations; Heat Transfer; Electric Power; Industrial and Coge

View full text Add to dashboard Cite

Experiments are conducted on a flat recovery wall downstream of sustained concave curvature in the presence of high free-stream turbulence (TI∼8%). This flow simulates some of the features of the flow on the latter parts of the pressure surface of a gas turbine airfoil. The combined effects of concave curvature and TI, both present in the flow over a turbine airfoil, have so far little been studied. Computation of such flows with standard turbulence closure models has not been particularly successful. This experiment attempts to characterize the turbulence characteristics of this flow. In the present study, a turbulent boundary layer grows from the leading edge of a concave wall then passes onto a downstream flat wall. Results show that turbulence intensities increase profoundly in the outer region of the boundary layer over the recovery wall. Near-wall turbulent eddies appear to lift off the recovery wall and a “stabilized” region forms near the wall. In contrast to a low-free-stream turbulence intensity flow, turbulent eddies penetrate the outer parts of the “stabilized” region where sharp velocity and temperature gradients exist. These eddies can more readily transfer momentum and heat. As a result, skin friction coefficients and Stanton numbers on the recovery wall are 20% and 10%, respectively, above their values in the low-free-stream turbulence intensity case. Stanton numbers do not undershoot flat-wall expectations at the same ReΔ2 values as seen in the low-TI case. Remarkably, the velocity distribution in the core of the flow over the recovery wall exhibits a negative gradient normal to the wall under high free-stream turbulence intensity conditions. This velocity distribution appears to be the result of two effects: 1) cross transport of kinetic energy by boundary work in the upstream curved flow and 2) readjustment of static pressure profiles in response to the removal of concave curvature.

show abstract

The Effect of Periodic Unsteady Flow on Aerodynamics and Heat Transfer on a Curved Surface

Wright

Schobeiri

1999

Journal of Heat Transfer

View full text Add to dashboard Cite

Aerodynamic and heat transfer investigations were performed on a constant curvature curved plate in a subsonic wind tunnel facility for various wake passing frequencies under zero pressure gradient conditions. Steady and unsteady boundary layer transition measurements were taken on the concave surface at different wake passing frequencies in which a rotating squirrel cage was used to generate the unsteady wake flow. The data were analyzed using time-averaged and ensemble averaged techniques to provide insight into the growth of the boundary layer and transition. Ensemble averaged turbulence intensity contours in the temporal spatial domain showed that transition was induced for increasing wake passing frequency and structure. The local heat transfer coefficient distributions for the concave and convex surfaces were determined for each wake passing frequency using a liquid crystal heat transfer measurement technique. Aerodynamic and heat transfer investigations showed that higher wake passing frequencies caused earlier transition on the concave surface. Local Stanton numbers were calculated on the concave surface and compared to Stanton numbers predicted using a boundary layer and heat transfer calculation method. On the convex side, no effect of wake passing on heat transfer was observed, due to a separation bubble that induced transition.

show abstract

Free-Stream Turbulence Effects on Convex-Curved Turbulent Boundary Layers

Cited by 4 publications

References 0 publications

Periodic Unsteady Flow Aerodynamics and Heat Transfer: Studies on a Curved Surface, Combined Part I and II

Periodic Unsteady Flow Aerodynamics and Heat Transfer: Studies on a Curved Surface, Combined Part I and II

Effects of Free-Stream Turbulence Intensity on a Boundary Layer Recovering From Concave Curvature Effects

The Effect of Periodic Unsteady Flow on Aerodynamics and Heat Transfer on a Curved Surface

Contact Info

Product

Resources

About