Abstract
The design and construction of a wind tunnel with a vertical working section, which was used successfully for the study of untethered firebrands at their terminal velocity, is described. Two unique features in this tunnel design set it aside from previous vertical wind tunnels: the vertical working section has a divergent taper that allows a firebrand to find its terminal velocity within a velocity gradient, and the velocity of the boundary layer of the working section has been forced to a higher speed than the central zone to stop the firebrand impacting on the working section walls. These features in combination with a responsive speed control on the fan allow observation of burning firebrands throughout their viable lifetime in freefall with changing terminal velocities. This paper is intended as a synthesis of wind tunnel design and as a guide to researchers considering building similar devices to study the untethered flight characteristics of local species of firebrands.
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Knight, I. The Design and Construction of a Vertical Wind Tunnel for the Study of Untethered Firebrands in Flight. Fire Technology 37, 87–100 (2001). https://doi.org/10.1023/A:1011605719943
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DOI: https://doi.org/10.1023/A:1011605719943