Abstract
Velocity and temperature distributions and heat transfer coefficient with combined free and forced laminar convection were investigated for annular flow between two vertical concentric cylinders, where a part of the inner cylinder was heated. By visualization of the flow pattern with a tracer, the fundamental equations of flow and heat transfer were derived and solved numerically. The velocity and temperature distributions in the annulus and the heat transfer coefficient on the heated wall were calculated with air. The range of Grashof number was 106-5×107, that of Reynolds number 25-800, radius ratio 1.2-3.7 and aspect ratio (cylinder length divided by annular gap) 3.7-22. The experimental temperature distributions and the heat transfer coefficient were in close agreement with the calculated values.
