Measurements in the transition vortex flow regime of mixed convection above a horizontal heated plate

Journal Article · Sun May 01 00:00:00 EDT 1988 · Journal of Heat Transfer (Transcations of the ASME (American Society of Mechanical Engineers), Series C); (United States)

DOI:https://doi.org/10.1115/1.3250492· OSTI ID:5465463

Moharreri, S S; Armaly, B F; Chen, T S ^[1]

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1. Univ. of Missouri, Rolla (USA)

Experimental results covering the transition vortex flow regime of mixed convection over a heated, horizontal flat plate are presented. A criterion for the onset of vortex instability as a function of critical Reynolds and Grashof numbers was established with the aid of a flow visualization technique. The three-dimensional nature of tis flow regime was documented through both velocity and temperature measurements using laser-Doppler and hot/cold-wire anemometers, respectively. A higher buoyancy force, through a higher plate temperature or a larger downstream distance and/or a lower free-stream velocity, intensifies the strength of the vortices. Velocity and temperature profiles through vortex peaks and valleys are reported to quantify the behavior of these vortices. It has been found from these measurements that the two-dimensional laminar mixed convection flow changes into a transitional three-dimensional vortex flow in a relatively short distance from the leading edge of the plate. The vortex three-dimensional flow continues to intensify as the buoyancy force increases and then develops into a two-dimensional fully turbulent flow at the end of the transition regime. These findings place an upper limit on the applicabilityof the two-dimensional, laminar boundary layer flow analysis for mixed convection a heated horizontal flat plate.

• OSTI ID: 5465463
• Journal Information: Journal of Heat Transfer (Transcations of the ASME (American Society of Mechanical Engineers), Series C); (United States), Journal Name: Journal of Heat Transfer (Transcations of the ASME (American Society of Mechanical Engineers), Series C); (United States) Vol. 110:2; ISSN 0022-1481; ISSN JHTRA
• Country of Publication: United States
• Language: English

Related Subjects

42 ENGINEERING
420400* -- Engineering-- Heat Transfer & Fluid Flow
ANEMOMETERS
CONVECTION
DATA
ENERGY TRANSFER
FLOW VISUALIZATION
FLUID FLOW
GRASHOF NUMBER
HEAT TRANSFER
HOT WIRE ANEMOMETERS
HYDROCARBONS
INFORMATION
MASS TRANSFER
MEASURING INSTRUMENTS
ORGANIC COMPOUNDS
PLATES
REYNOLDS NUMBER
TEMPERATURE MEASUREMENT
VELOCITY
VORTEX FLOW