Dynamics of the vortex wakes of flying and swimming vertebrates
- PMID: 8571221
Dynamics of the vortex wakes of flying and swimming vertebrates
Abstract
The vortex wakes of flying and swimming animals provide evidence of the history of aero- and hydrodynamic force generation during the locomotor cycle. Vortex-induced momentum flux in the wake is the reaction of forces the animal imposes on its environment, which must be in equilibrium with inertial and external forces. In flying birds and bats, the flapping wings generate lift both to provide thrust and to support the weight. Distinct wingbeat and wake movement patterns can be identified as gaits. In flow visualization experiments, only two wake patterns have been identified: a vortex ring gait with inactive upstroke, and a continuous vortex gait with active upstroke. These gaits may be modelled theoretically by free vortex and lifting line theory to predict mechanical energy consumption, aerodynamic forces and muscle activity. Longer-winged birds undergo a distinct gait change with speed, but shorter-winged species use the vortex ring gait at all speeds. In swimming fish, the situation is more complex: the wake vortices form a reversed von Kármán vortex street, but little is known about the mechanism of generation of the wake, or about how it varies with speed and acceleration or with body form and swimming mode. An unresolved complicating factor is the interaction between the drag wake of the flapping fish body and the thrusting wake from the tail.
Similar articles
-
Biomechanics and physiology of gait selection in flying birds.Physiol Biochem Zool. 2000 Nov-Dec;73(6):736-50. doi: 10.1086/318107. Physiol Biochem Zool. 2000. PMID: 11121347 Review.
-
Vortex-wake interactions of a flapping foil that models animal swimming and flight.J Exp Biol. 2008 Jan;211(Pt 2):267-73. doi: 10.1242/jeb.006155. J Exp Biol. 2008. PMID: 18165254
-
Hydrodynamics of surface swimming in leopard frogs (Rana pipiens).J Exp Biol. 2004 Oct;207(Pt 22):3945-58. doi: 10.1242/jeb.01258. J Exp Biol. 2004. PMID: 15472025
-
Vortex wake and flight kinematics of a swift in cruising flight in a wind tunnel.J Exp Biol. 2008 Mar;211(Pt 5):717-30. doi: 10.1242/jeb.012146. J Exp Biol. 2008. PMID: 18281334
-
When wings touch wakes: understanding locomotor force control by wake wing interference in insect wings.J Exp Biol. 2008 Jan;211(Pt 2):224-33. doi: 10.1242/jeb.007575. J Exp Biol. 2008. PMID: 18165250 Review.
Cited by
-
Wing Musculature Reconstruction in Extinct Flightless Auks (Pinguinus and Mancalla) Reveals Incomplete Convergence with Penguins (Spheniscidae) Due to Differing Ancestral States.Integr Org Biol. 2020 Nov 11;3(1):obaa040. doi: 10.1093/iob/obaa040. eCollection 2021. Integr Org Biol. 2020. PMID: 34258512 Free PMC article.
-
A well-preserved partial scapula from Japan and the reconstruction of the triosseal canal of plotopterids.PeerJ. 2018 Aug 25;6:e5391. doi: 10.7717/peerj.5391. eCollection 2018. PeerJ. 2018. PMID: 30155348 Free PMC article.
-
Stroke and glide of wing-propelled divers: deep diving seabirds adjust surge frequency to buoyancy change with depth.Proc Biol Sci. 2003 Mar 7;270(1514):483-8. doi: 10.1098/rspb.2002.2252. Proc Biol Sci. 2003. PMID: 12641902 Free PMC article.