Date Available

4-15-2016

Year of Publication

2016

Document Type

Master's Thesis

Degree Name

Master of Science in Mechanical Engineering (MSME)

College

Engineering

Department/School/Program

Mechanical Engineering

Advisor

Dr. Kozo Saito

Abstract

This thesis reports small-scale laboratory experiments designed to visualize the flow over a heated plate. A low-speed wind tunnel was built, and a heating plate was flush mounted on the wind tunnel floor to provide a uniform heat flux over its surface. A paper thin cloth soaked with commercially available Vaseline was placed on top of the heating plate to produce thick smoke streaks that were carried downstream by a horizontal airflow. Both LED light and a laser sheet of approximately 30-degrees open angle were separately used to illuminate this flow, the latter advanced downstream with 1-cm interval from the heated plate’s upstream edge. A camera with full-frame CMOS sensor recorded time series of flow patterns from four different angles. From these images, the following four flow structures were identified: (1) organized horizontal flow of vortex tubes, (2) weak vortex tubes interactions, (3) strong vortex tubes interactions (transition regime), (4) chaotic turbulent flow. Flow structure analysis showed that smoke flow height increased with horizontal distance from the heated plate and reduced with flow velocity. Scaling analysis was conducted to assess the validity of observed scale model flow structure to the USDA Forest Service medium scale wind tunnel burns.

Digital Object Identifier (DOI)

http://dx.doi.org/10.13023/ETD.2016.073

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