Flow visualization studies of free convection laminar-to-turbulent transition along a heated vertical plate in water induced by two-dimensional forced disturbances

1971 ◽  
Vol 4 (1) ◽  
pp. 25-31 ◽  
Author(s):  
P. Čolak-Antić ◽  
H. Görtler
Keyword(s):  
Free Convection ◽  
Flow Visualization ◽  
Vertical Plate ◽  
Two Dimensional ◽  
Laminar To Turbulent Transition ◽  
Turbulent Transition

Study of the Laminar Free-Convection Wake Above an Isothermal Vertical Plate

1973 ◽  
Vol 95 (3) ◽  
pp. 289-294 ◽  
Author(s):  
N. E. Hardwick ◽  
E. K. Levy
Keyword(s):  
Free Convection ◽  
Vertical Plate ◽  
Fluid Motion ◽  
Heated Plate ◽  
Two Dimensional ◽  
Wake Region ◽  
Hot Wire ◽  
Near Wake ◽  
Steady Laminar ◽  
Finite Difference Techniques

The steady, laminar, two-dimensional wake above a thin vertical isothermal heated plate cooled by free convection was investigated theoretically and experimentally. The system of partial differential equations governing the fluid motion and heat transfer in the vicinity of the plate and in the near wake region was formulated and solved using finite difference techniques. Using air, the temperature and velocity profiles in the wake region were measured experimentally using a laser holographic interferometer and a constant temperature hot wire anemometer.

scholarly journals A Study of Two Dimensional Unsteady MHD Free Convection Flow over a Vertical Plate

2020 ◽  
Vol 10 (04) ◽  
pp. 342-355
Author(s):  
Absana Tarammim ◽  
Mohammad Sharif Ullah ◽  
Mohammed Jahir Uddin
Keyword(s):  
Free Convection ◽  
Vertical Plate ◽  
Convection Flow ◽  
Two Dimensional ◽  
Free Convection Flow

scholarly journals Heat Transfer and Flow Visualization in Natural Convection in Rapidly Spinning Systems

1986 ◽  
Vol 108 (3) ◽  
pp. 547-553 ◽  
Author(s):  
L. Sobel ◽  
M. El-Masri ◽  
J. L. Smith
Keyword(s):  
Heat Transfer ◽  
Free Convection ◽  
Flow Visualization ◽  
Fluid Viscosity ◽  
Two Dimensional ◽  
Thermal Plumes ◽  
Buoyant Plumes ◽  
Thermal Transients ◽  
Wide Range ◽  
Prandtl Numbers

The design of airborne superconducting generators for intermittent duty requires the understanding of some unique free-convection processes in the spinning helium bath. Toward that end, some fundamental experiments on steady and transient free convection in rotating containers of representative geometries have been performed. Heat transfer data from heaters of various geometries mounted on the outer container surface to several fluids are reported. A correlation for steady-state Nusselt number is presented for a wide range of Rayleigh and Prandtl numbers. The heat transfer coefficient was found to be independent of heater size, geometry, and fluid viscosity. Heat transfer measurements during simultaneous thermal transients and sudden increases in rotational speed were also made. They show an enhancement of heat transfer due to the relative counterrotation of the fluid following the acceleration of the container. This persists for a period well below that for fluid spinup. A model based upon the submergence of the thermal boundary layer by the diffusive wave from the wall was successful in correlating this period. Quasi-steady flow visualization experiments indicate that the thermal plumes generate two-dimensional, axially invariant flow fields. Their trajectories are radial relative to the spinning container. Those observations are shown to be consistent with the fact that weak buoyant plumes in containers rotating at small Ekman numbers result in low Rossby number motions. Those are two dimensional according to the Taylor–Proudman theorem. It is shown that the Coriolis and pressure forces on such a thermal column are in azimuthal equilibrium, hence the radial trajectory. Flow visualization following impulsive acceleration in an off-axis, nonaxisymmetric container shows that the flow field is dominated by vortices expelled from corners. The fluid spinup time, however, was found to be the same as that for an on-axis circular cylinder of the same characteristic diameter.

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