scholarly journals Wing inertia and whole-body acceleration: an analysis of instantaneous aerodynamic force production in cockatiels (Nymphicus hollandicus) flying across a range of speeds

2004 ◽  
Vol 207 (10) ◽  
pp. 1689-1702 ◽  
Author(s):  
T. L. Hedrick
Keyword(s):  
Aerodynamic Force ◽  
Force Production ◽  
Whole Body ◽  
Body Acceleration ◽  
Nymphicus Hollandicus

scholarly journals Maximum aerodynamic force production by the wandering glider dragonfly (Pantala flavescens, Libellulidae)

2020 ◽  
Vol 223 (14) ◽  
pp. jeb218552
Author(s):  
Guanting Su ◽  
Robert Dudley ◽  
Tianyu Pan ◽  
Mengzong Zheng ◽  
Liansong Peng ◽  
...  
Keyword(s):  
Body Mass ◽  
Body Force ◽  
Aerodynamic Force ◽  
Behavioral Outcomes ◽  
Force Production ◽  
Maximum Force ◽  
Whole Body ◽  
Group Level ◽  
Aerodynamic Optimization ◽  
A Value

ABSTRACTMaximum whole-body force production can influence behavioral outcomes for volant taxa, and may also be relevant to aerodynamic optimization in microair vehicles. Here, we describe a new method for measuring maximum force production in free-flying animals, and present associated data for the wandering glider dragonfly. Flight trajectories were repeatedly acquired from pull-up responses by insects dropped in mid-air with submaximal loads attached beneath the center of body mass. Forces were estimated from calculations of the maximum time-averaged acceleration through time, and multiple estimates were obtained per individual so as to statistically facilitate approximation of maximum capacity through use of the Weibull distribution. On a group level, wandering glider dragonflies were here estimated to be capable of producing total aerodynamic force equal to ∼4.3 times their own body weight, a value which significantly exceeds earlier estimates made for load-lifting dragonflies, and also for other volant taxa in sustained vertical load-lifting experiments. Maximum force production varied isometrically with body mass. Falling and recovery flight with submaximal load represents a new context for evaluating limits to force production by flying animals.

Pressure Changes Induced by Whole Body Acceleration Shocks

1991 ◽  
Vol 113 (1) ◽  
pp. 27-29 ◽  
Author(s):  
E. Belardinelli ◽  
M. Ursino ◽  
G. Fabbri ◽  
A. Cevese ◽  
F. Schena
Keyword(s):  
Mathematical Model ◽  
Carotid Artery ◽  
Normal Pressure ◽  
Compressed Air ◽  
Whole Body ◽  
Body Acceleration ◽  
Vascular Bed ◽  
Pressure Changes ◽  
The Mathematical Model

In the present paper pressure changes induced by sudden body acceleration are studied “in vivo” on the dog and compared to the results obtainable with a recently developed mathematical model. A dog was fixed to a movable table, which was accelerated by a compressed air piston for less than 1 s. Acceleration was varied by changing the air pressure in the piston. Pressure was measured during the experiment at different points along the vascular bed. However, only data obtained in the carotid artery and abdominal aorta are presented here. The results demonstrated that impulse body accelerations cause significant pressure peaks in the vessel examined (about + 25 mmHg in the carotid artery with body acceleration of g/2). Moreover, pressure changes are rapidly damped, with a time constant of about 0.1s. From the present results it may be concluded that, according to the prediction of the mathematical model, body accelerations such as those occurring in normal life can induce pressure changes well beyond the normal pressure value.

scholarly journals Lower Body Acceleration and Muscular Responses to Rotational and Vertical Whole-Body Vibration at Different Frequencies and Amplitudes

Dose-Response ◽  
2019 ◽  
Vol 17 (1) ◽  
pp. 155932581881994 ◽  
Author(s):  
Lisa N. Zaidell ◽  
Ross D. Pollock ◽  
Darren C. James ◽  
Joanna L. Bowtell ◽  
Di J. Newham ◽  
...  
Keyword(s):  
Whole Body Vibration ◽  
Whole Body ◽  
Lower Body ◽  
Body Acceleration ◽  
Body Vibration ◽  
Muscular Responses

scholarly journals Biases in the perception of self-motion during whole-body acceleration and deceleration

2013 ◽  
Vol 7 ◽  
Author(s):  
Luc Tremblay ◽  
Andrew Kennedy ◽  
Dany Paleressompoulle ◽  
Liliane Borel ◽  
Laurence Mouchnino ◽  
...  
Keyword(s):  
Whole Body ◽  
Body Acceleration ◽  
Acceleration And Deceleration ◽  
Perception Of Self ◽  
Self Motion

Deformable Blade Element and Unsteady Vortex Lattice Fluid-Structure Interaction Modeling of a 2D Flapping Wing

2020 ◽  
Author(s):  
Joseph Reade ◽  
Mark A. Jankauski
Keyword(s):  
Vortex Lattice ◽  
Normal Force ◽  
Aerodynamic Force ◽  
Fluid Structure Interaction ◽  
Force Production ◽  
Flapping Wing ◽  
Energetic Efficiency ◽  
Fluid Structure ◽  
Structure Interaction ◽  
Blade Element

Abstract Flapping insect wings experience appreciable deformation due to aerodynamic and inertial forces. This deformation is believed to benefit the insect’s aerodynamic force production as well as energetic efficiency. However, the fluid-structure interaction (FSI) models used to estimate wing deformations are often computationally demanding and are therefore challenged by parametric studies. Here, we develop a simple FSI model of a flapping wing idealized as a two-dimensional pitching-plunging airfoil. Using the Lagrangian formulation, we derive the reduced-order structural framework governing wing’s elastic deformation. We consider two fluid models: quasi-steady Deformable Blade Element Theory (DBET) and Unsteady Vortex Lattice Method (UVLM). DBET is computationally economical but does not provide insight into the flow structure surrounding the wing, whereas UVLM approximates flows but requires more time to solve. For simple flapping kinematics, DBET and UVLM produce similar estimates of the aerodynamic force normal to the surface of a rigid wing. More importantly, when the wing is permitted to deform, DBET and UVLM agree well in predicting wingtip deflection and aerodynamic normal force. The most notable difference between the model predictions is a roughly 20° phase difference in normal force. DBET estimates wing deformation and force production approximately 15 times faster than UVLM for the parameters considered, and both models solve in under a minute when considering 15 flapping periods. Moving forward, we will benchmark both low-order models with respect to high fidelity computational fluid dynamics coupled to finite element analysis, and assess the agreement between DBET and UVLM over a broader range of flapping kinematics.

Cardiovascular responses to low‐frequency whole‐body acceleration

1981 ◽  
Vol 70 (S1) ◽  
pp. S36-S36
Author(s):  
C. Knapp ◽  
J. Evans ◽  
D. Randall ◽  
J. Marquis ◽  
A. Bhattacharya
Keyword(s):  
Low Frequency ◽  
Cardiovascular Responses ◽  
Whole Body ◽  
Body Acceleration

Effects of Whole Body Vibration on Force Production in Young, Middle-aged, and Older Men

2007 ◽  
Vol 39 (Supplement) ◽  
pp. S102
Author(s):  
Eric F. Mathe ◽  
Joel T. Cramer ◽  
Debra A. Bemben ◽  
Michael G. Bemben
Keyword(s):  
Whole Body Vibration ◽  
Force Production ◽  
Older Men ◽  
Whole Body ◽  
Middle Aged ◽  
Body Vibration

scholarly journals Reconstructing Full-Field Flapping Wing Dynamics from Sparse Measurements

2020 ◽  
Author(s):  
William Johns ◽  
Lisa Davis ◽  
Mark Jankauski
Keyword(s):  
Aerodynamic Force ◽  
Force Production ◽  
Energetic Efficiency ◽  
Reconstruction Technique ◽  
Reconstruction Method ◽  
Full Field ◽  
Insect Wing ◽  
Insect Wings ◽  
Flying Insects ◽  
Sparse Measurements

AbstractFlapping insect wings deform during flight. This deformation benefits the insect’s aerodynamic force production as well as energetic efficiency. However, it is challenging to measure wing displacement field in flying insects. Many points must be tracked over the wing’s surface to resolve its instantaneous shape. To reduce the number of points one is required to track, we propose a physics-based reconstruction method called System Equivalent Reduction Expansion Processes (SEREP) to estimate wing deformation and strain from sparse measurements. Measurement locations are determined using a Weighted Normalized Modal Displacement (NMD) method. We experimentally validate the reconstruction technique by flapping a paper wing from 5-9 Hz with 45° and measuring strain at three locations. Two measurements are used for the reconstruction and the third for validation. Strain reconstructions had a maximal error of 30% in amplitude. We extend this methodology to a more realistic insect wing through numerical simulation. We show that wing displacement can be estimated from sparse displacement or strain measurements, and that additional sensors spatially average measurement noise to improve reconstruction accuracy. This research helps overcome some of the challenges of measuring full-field dynamics in flying insects and provides a framework for strain-based sensing in insect-inspired flapping robots.

scholarly journals THE LOCUST TEGULA: SIGNIFICANCE FOR FLIGHT RHYTHM GENERATION, WING MOVEMENT CONTROL AND AERODYNAMIC FORCE PRODUCTION

1993 ◽  
Vol 182 (1) ◽  
pp. 229-253 ◽  
Author(s):  
H Wolf
Keyword(s):  
Flight Control ◽  
Aerodynamic Force ◽  
Motor Pattern ◽  
Vertical Component ◽  
Sense Organ ◽  
Force Production ◽  
Movement Control ◽  
Rhythm Generation ◽  
Wing Movement ◽  
Before And After

The tegula, a complex sense organ associated with the wing base of the locust, plays an important role in the generation of the flight motor pattern. Here its function in the control of wing movement and aerodynamic force production is described.The vertical component of forewing movement was monitored while recording intracellularly from flight motoneurones during stationary flight. First, in accordance with previous electrophysiological results, stimulation of hindwing tegula afferents was found to reset the wingstroke to the elevation phase in a well-coordinated manner. Second, recordings made before and after removal of fore- and hindwing tegulae were compared. This comparison demonstrated that the delayed onset of elevator motoneurone activity caused by tegula removal is accompanied by a corresponding delay in the upstroke movement of the wings.The consequences of this delayed upstroke for aerodynamic force production were investigated by monitoring wing movements and lift generation simultaneously. A marked decrease in net lift generation was observed following tegula removal. Recordings of wing pronation indicate that this decrease in lift is primarily due to the delayed upstroke movement - that is, to a delay of the wings near the aerodynamically unfavourable downstroke position.It is concluded that the tegula of the locust hindwing signals to the nervous system the impending completion of the wing downstroke and allows initiation of the upstroke movement immediately after the wings have reached the lower reversal point of the wingstroke. The functional significance of tegula feedback and central rhythm generation for locust flight control are discussed.

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