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The complex aerodynamic footprint of desert locusts revealed by large-volume tomographic particle image velocimetry.

Henningsson P, Michaelis D, Nakata T, Schanz D, Geisler R, Schröder A, Bomphrey RJ - J R Soc Interface (2015)

Bottom Line: Particle image velocimetry has been the preferred experimental technique with which to study the aerodynamics of animal flight for over a decade.We confirm the presence of wake deformation behind desert locusts and quantify the effect of that deformation on estimates of aerodynamic force and the efficiency of lift generation.We present previously undescribed vortex wake phenomena, including entrainment around the wing-tip vortices of a set of secondary vortices borne of Kelvin-Helmholtz instability in the shear layer behind the flapping wings.

View Article: PubMed Central - PubMed

Affiliation: Department of Biology, Lund University, Lund, Sweden.

No MeSH data available.


(a) Span efficiency at the five different downstream locations. There is no significant change over the measured distance. (b) Weight support at the five different downstream locations. Weight support decreases with downstream location, but appears to level out towards the downstream end.
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RSIF20150119F6: (a) Span efficiency at the five different downstream locations. There is no significant change over the measured distance. (b) Weight support at the five different downstream locations. Weight support decreases with downstream location, but appears to level out towards the downstream end.

Mentions: We calculated aerodynamic span efficiency for each of the five locusts and simulated stereo sampling planes from five downstream locations using our volumetric data. The mean span efficiency of the five locusts and samples from all five downstream locations was ei = 0.82, higher than the figure of 0.53 reported previously [5]. Span efficiency did not change significantly with downstream distance of the vector fields (ANOVA; p = 0.087). The values stay close to constant regardless of whether the vector field that was used for the estimate was extracted from the plane closest to the animal or the plane furthest away (figure 6a). This is an encouraging result in the context of the robustness of flight efficiency studies using PIV.Figure 6.


The complex aerodynamic footprint of desert locusts revealed by large-volume tomographic particle image velocimetry.

Henningsson P, Michaelis D, Nakata T, Schanz D, Geisler R, Schröder A, Bomphrey RJ - J R Soc Interface (2015)

(a) Span efficiency at the five different downstream locations. There is no significant change over the measured distance. (b) Weight support at the five different downstream locations. Weight support decreases with downstream location, but appears to level out towards the downstream end.
© Copyright Policy - open-access
Related In: Results  -  Collection

License
Show All Figures
getmorefigures.php?uid=PMC4528577&req=5

RSIF20150119F6: (a) Span efficiency at the five different downstream locations. There is no significant change over the measured distance. (b) Weight support at the five different downstream locations. Weight support decreases with downstream location, but appears to level out towards the downstream end.
Mentions: We calculated aerodynamic span efficiency for each of the five locusts and simulated stereo sampling planes from five downstream locations using our volumetric data. The mean span efficiency of the five locusts and samples from all five downstream locations was ei = 0.82, higher than the figure of 0.53 reported previously [5]. Span efficiency did not change significantly with downstream distance of the vector fields (ANOVA; p = 0.087). The values stay close to constant regardless of whether the vector field that was used for the estimate was extracted from the plane closest to the animal or the plane furthest away (figure 6a). This is an encouraging result in the context of the robustness of flight efficiency studies using PIV.Figure 6.

Bottom Line: Particle image velocimetry has been the preferred experimental technique with which to study the aerodynamics of animal flight for over a decade.We confirm the presence of wake deformation behind desert locusts and quantify the effect of that deformation on estimates of aerodynamic force and the efficiency of lift generation.We present previously undescribed vortex wake phenomena, including entrainment around the wing-tip vortices of a set of secondary vortices borne of Kelvin-Helmholtz instability in the shear layer behind the flapping wings.

View Article: PubMed Central - PubMed

Affiliation: Department of Biology, Lund University, Lund, Sweden.

No MeSH data available.