Measurements in buoyancy-assisting laminar boundary layer flow over a vertical backward-facing step - Uniform wall heat flux case

Journal Article · Thu Jul 01 04:00:00 EDT 1993 · Experimental Thermal and Fluid Science; (United States)

DOI:https://doi.org/10.1016/0894-1777(93)90079-X· OSTI ID:5951761

Abu-mulaweh, H I; Armaly, B F; Chen, T S ^[1]

---

1. Missouri-Rolla Univ., Rolla (United States)

Measurements and predictions of velocity and temperature distributions in buoyancy-assisting, laminar, mixed convection boundary layer flow over a vertical 2D backward-facing step are presented. The wall downstream of the step was subjected to a uniform wall heat flux, and the wall upstream of the step and the step itself were kept adiabatic. Velocity and temperature distributions were measured simultaneously by using a laser-Doppler velocimeter and a cold-wire anemometer. Flow visualization was also carried out to determine the reattachment length. The experiment covered a range of levels of wall heat flux, free-stream velocities, and step heights. The results indicate that as the wall heat flux increases, the Nusselt number increases but the reattachment length decreases. The measured results reveal that axial conduction along the constant heat flux surface is very significant in the recirculation region. This finding necessitates the coupling of the convective heat transfer from the wall to the fluid with the axial conduction along the constant heat flux wall in order to accurately predict the measured data by the numerical solution. 20 refs.

• OSTI ID: 5951761
• Journal Information: Experimental Thermal and Fluid Science; (United States), Journal Name: Experimental Thermal and Fluid Science; (United States) Vol. 7:1; ISSN 0894-1777; ISSN ETFSEO
• Country of Publication: United States
• Language: English

Related Subjects

42 ENGINEERING
420400* -- Engineering-- Heat Transfer & Fluid Flow
ANEMOMETERS
BOUNDARY LAYERS
CONVECTION
ENERGY TRANSFER
FLOW VISUALIZATION
FLUID FLOW
HEAT FLUX
HEAT TRANSFER
LASER DOPPLER ANEMOMETERS
LAYERS
MASS TRANSFER
MATHEMATICS
MEASURING INSTRUMENTS
NUMERICAL ANALYSIS
NUSSELT NUMBER
TEMPERATURE MEASUREMENT