Vortex instability of horizontal and inclined natural convection flows from simultaneous thermal and mass diffusion
Abstract
An analysis is performed to study the heat/mass transfer and vortex instability characteristics of buoyancyinduced flows that result from simultaneous diffusion of heat and mass in laminar boundary layers adjacent to horizontal and inclined surfaces. Numerical results are obtained for a Prandtl number of 0.7 over a range of Schmidt numbers and various angles of inclination from the horizontal, phi. For a given phi, it is found that when the two buoyancy forces from thermal and mass diffusion act in the same direction, both the surface heat and mass transfer rates increase, causing the flow to become more susceptible to the vortex mode of instability. These trends are reversed when the two buoyancy forces act in the opposite directions. On the other hand, as phi is increased, the heat and mass transfer rates are enhanced, but the instability of the flow to the vortex mode of disturbances decreases and eventually vanishes at phi = 90 deg.
 Publication:

American Society of Mechanical Engineers
 Pub Date:
 November 1981
 Bibcode:
 1981asme.meetV....C
 Keywords:

 Convective Flow;
 Flow Stability;
 Mass Transfer;
 Surface Temperature;
 Thermal Diffusion;
 Vortices;
 Buoyancy;
 Computational Fluid Dynamics;
 Convective Heat Transfer;
 Laminar Boundary Layer;
 Prandtl Number;
 Schmidt Number;
 Fluid Mechanics and Heat Transfer