Numerical assessment of wake-based estimation of instantaneous lift in flapping flight of large birds

Experimental characterization of bird flight without instrumenting the animal requires measuring the flow behind the bird in a wind tunnel. Models are used to link the measured velocities to the corresponding aerodynamic forces. Widely-used models can, however, prove inconsistent when evaluating the...

Full description

Saved in:
Bibliographic Details
Published in:PloS one 2023-05, Vol.18 (5), p.e0284714-e0284714
Main Authors: Colognesi, Victor, Ronsse, Renaud, Chatelain, Philippe
Format: Article
Language:English
Subjects:
Added mass effects
Aerodynamic forces
Analysis
Animals
Biology and Life Sciences
Biomechanical Phenomena
Birds
Conservation
Estimation
Evaluation
Flapping wings
Flight
Flight, Animal
Latency
Lift
Mathematical analysis
Mathematical models
Medicine and Health Sciences
Models, Biological
Numerical analysis
Physical instruments
Physical Sciences
Protection and preservation
Reynolds number
Simulation
Validity
Velocity
Vortices
Wakes
Wind tunnels
Wings, Animal
Citations: Items that this one cites
Online Access:Get full text
Tags: Add Tag
No Tags, Be the first to tag this record!
Description
Summary:Experimental characterization of bird flight without instrumenting the animal requires measuring the flow behind the bird in a wind tunnel. Models are used to link the measured velocities to the corresponding aerodynamic forces. Widely-used models can, however, prove inconsistent when evaluating the instantaneous lift. Yet, accurately estimating variations of lift is critical in order to reverse-engineer flapping flight. In this work, we revisit mathematical models of lift based on the conservation of momentum in a control volume around a bird. Using a numerical framework to represent a flapping bird wing and compute the flow around it, we mimic the conditions of a wind tunnel and produce realistic wakes, which we compare to experimental data. Providing ground truth measurements of the flow everywhere around the simulated bird, we assess the validity of several lift estimation techniques. We observe that the circulation-based component of the instantaneous lift can be retrieved from measurements of velocity in a single plane behind a bird, with a latency that is found to depend directly on the free-stream velocity. We further show that the lift contribution of the added-mass effect cannot be retrieved from such measurements and quantify the level of approximation due to ignoring this contribution in instantaneous lift estimation.
ISSN:1932-6203
1932-6203
DOI:10.1371/journal.pone.0284714