Welcome to the new version of CaltechAUTHORS. Login is currently restricted to library staff. If you notice any issues, please email coda@library.caltech.edu
Published February 1981 | Published
Journal Article Open

Measurements of Unsteady Periodic Forces generated by the Blowfly Flying in a Wind Tunnel

Abstract

A technique was developed for the measurement of the instantaneous lift and drag forces generated by the blowfly, Sarcophaga bullata, flying fixed in a wind tunnel. Apparatus for the measurement of insect-generated forces was checked in part for mean force accuracy by measurement of the drag on a circular cylinder. Our experimental device detects the sum of the aerodynamic forces and wing inertial forces as experienced by the thorax. The streamwise and vertical force waveforms show a surprising lack of higher harmonic content. Wind speeds in the neighbourhood of the known preferred flying speed were used, without an explicit attempt to nullify the mean vertical and horizontal forces to simulate free flight. Several measurements of the phase angle between the force waveform and the wing beating kinematics indicated that vertical forces in the liftward direction achieved a maximum during the downstroke and thrustward forces achieved a maximum during the upstroke.

Additional Information

© 1981 by Company of Biologists. Revision received March 26, 1980. I would like to thank Professor S. Corrsin, who jointly conceived the system and reviewed this manuscript. This work was supported by the National Science Foundation, Engineering Mechanics and Biophysical Fluid Mechanics Programs.

Attached Files

Published - BUCjeb81.pdf

Files

BUCjeb81.pdf
Files (414.9 kB)
Name Size Download all
md5:be3f77083a919f00c015413285e2d059
414.9 kB Preview Download

Additional details

Created:
August 19, 2023
Modified:
October 18, 2023