Turbulent Mixed Convection Flow Over a Backward-Facing Step

Abstract

Measurements of turbulent mixed convection flow over a two-dimensional, vertical backward-facing step are reported. Laser-Doppler velocimeter (LDV) and cold wire anemometer were used, respectively, to measure simultaneously the time-mean velocity and temperature distributions and their turbulent fluctuations. The experiment was carried out for a range of free stream air velocities 0 m/su∞0.41 m/s for a step height of 22 mm, and a temperature difference, ΔT, of 30°C between the heated walls and the free stream air. The step geometry consists of an adiabatic backward-facing step, an upstream wall and a downstream wall. Both the upstream and downstream walls are heated to a uniform and constant temperature. The present results reveal that the introduction of a small free stream velocity causes a decrease in the turbulence intensity of both the streamwise and transverse velocity and temperature fluctuations. Also, it was found that the reattachment length increases while the heat transfer rate from the downstream heated wall decreases as the free stream velocity increases.

Department(s)

Mechanical and Aerospace Engineering

Sponsor(s)

National Science Foundation (U.S.)

Keywords and Phrases

Cold Wire Anemometer; Two-Dimensional-Vertical Backward-Facing Step; Laser Doppler velocimeter

International Standard Serial Number (ISSN)

0017-9310

Document Type

Article - Journal

Document Version

Citation

File Type

text

Language(s)

English

Rights

© 2001 Elsevier, All rights reserved.

Publication Date

01 Jul 2001

Link to Full Text

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