Buoyancy effects on a boundary layer along an infinite vertical cylinder with a step change of surface temperature
Abstract
The laminar boundary layer which is induced by a horizontal forced flow along an infinite vertical cylinder with a step change of surface temperatures is studied by a finitedifference method. Close to the thermal leading edge, the buoyancy force induces a strong freeconvection boundary layer. Slightly above the thermal leading edge, the boundary layer starts to separate at the rear stagnation point (phi = 180 deg). The region of the separated flow grows forward and becomes stationary at phi = 104 deg as one moves upward. In other words, the free convection dominates the heat transfer along the thermal leading edge. The importance of the forced convection increases as one moves upward vertically from the thermal leading edge and eventually becomes the dominant mode. The numerical results show that the freeconvection boundary layer is suppressed at the forward stagnation point and is carried toward the rear stagnation point by the forced convection. The phenomenon shares many similarities with a thermal plume effected by a forced convection.
 Publication:

American Society of Mechanical Engineers
 Pub Date:
 November 1980
 Bibcode:
 1980asme.meetQ....Y
 Keywords:

 Boundary Layer Stability;
 Buoyancy;
 Cylindrical Bodies;
 Surface Temperature;
 Thermal Boundary Layer;
 Convective Heat Transfer;
 Free Convection;
 Laminar Boundary Layer;
 Transient Heating;
 Fluid Mechanics and Heat Transfer