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Aerodynamics and Fluid Mechanics Commons™
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- Turbulence (3)
- Aerodynamics (1)
- Boundary Layer (1)
- Boundary layer flow (1)
- Chemosensing (1)
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- Computational Fluid Dynamics (1)
- Computational fluid dynamics (1)
- Flapping flight aerodynamics (1)
- Flow control (1)
- Flume (1)
- High-speed kinematics (1)
- High-speed time-resolved PIV (1)
- Male moth (1)
- Navier Stokes equations (1)
- Navigation performance (1)
- Odor source (1)
- Odorscape (1)
- Open Channel Flow (1)
- Owl wing (1)
- Owls and Hawks (1)
- Owls' aerodynamics (1)
- PIV (1)
- Particle Image Velocimetry (1)
- Pressure (1)
- Sex pheromone (1)
- Silent flight (1)
- Silent flight of owl (1)
- Spectral Analysis (1)
- Suction-feeding (1)
- Turbulent flows (1)
- Publication Type
Articles 1 - 8 of 8
Full-Text Articles in Aerodynamics and Fluid Mechanics
Gust-Induced Aerodynamic Performance In Insects' Forward Flapping Flight, Arash Farsani, Ori Stearns, Gal Ribak, Roi Gurka
Gust-Induced Aerodynamic Performance In Insects' Forward Flapping Flight, Arash Farsani, Ori Stearns, Gal Ribak, Roi Gurka
Physics and Engineering Science
Flapping-wing flight is inherently unsteady, where atmospheric gusts can substantially degrade the aerodynamic performance when their characteristic time scales are comparable to the wingbeat period. This study presents a numerical investigation and time–frequency characterization of gust-induced aerodynamic response of flapping wings of varying size, inspired by the flight of a longhorn beetle, Batocera rufomaculata. Geometrically similar wings spanning the biological range were simulated in forward flight under identical prescribed kinematics and a transient frontal gust with a smoothly ramped profile. Three-dimensional unsteady Reynolds-averaged Navier–Stokes simulations using the shear stress transport k–ω turbulence model were performed to resolve the instantaneous pressure …
Pressure Field Estimation From 2d-Piv Measurements: A Case Study Of Fish Suction-Feeding, Jensine C. Coggin, Duvall Dickerson-Evans, Erin E. Hackett, Roi Gurka
Pressure Field Estimation From 2d-Piv Measurements: A Case Study Of Fish Suction-Feeding, Jensine C. Coggin, Duvall Dickerson-Evans, Erin E. Hackett, Roi Gurka
Physics and Engineering Science
Particle image velocimetry (PIV) flow measurements are common practice in laboratory settings in a wide variety of fields involving fluid dynamics, including biology, physics, engineering, and medicine. Dynamic fluid pressure is a notoriously difficult property to measure non-intrusively, yet its variation is a driving flow force and critical to model correctly. Techniques have been developed to estimate the pressure from velocity and velocity gradient measurements. Here, we highlight a novel application of boundary conditions when applying such pressure estimation techniques based on two-dimensional PIV data; the novel method is especially relevant to problems with complex boundary conditions. As such, it …
Insect Wing Flexibility Improves The Aerodynamic Performance Of Small Revolving Wings, Gal Ribak, Ori Stearns, Kiruthika Sundararajan, Duvall Dickerson-Evans, Dana Melamed, Maya Rabinovich, Roi Gurka
Insect Wing Flexibility Improves The Aerodynamic Performance Of Small Revolving Wings, Gal Ribak, Ori Stearns, Kiruthika Sundararajan, Duvall Dickerson-Evans, Dana Melamed, Maya Rabinovich, Roi Gurka
Physics and Engineering Science
Insect wings are flexible, elastically deforming under loads experienced during flapping. The adaptive value of this flexibility was tested using a revolving wing set-up. We show that the wing flexibility of the beetle Batocera rufomaculata, suppresses the reduction in lift coefficient that is expected to occur with a reduction of wing size compared to rigid propeller blades. Moreover, the scaling of wing flexibility with size is intra-specifically tuned through changes in wing-vein cross-section, resulting in smaller wings achieving proportionally larger chordwise deformations compared to larger wings, when loaded with aerodynamic forces. These elastic deformations control the separation of flow from …
Physical And Biological Effects On Moths’ Navigation Performance, Yiftach Golov, Roi Gurka, Alexander Liberzon, Ally Harari
Physical And Biological Effects On Moths’ Navigation Performance, Yiftach Golov, Roi Gurka, Alexander Liberzon, Ally Harari
Physics and Engineering Science
In a chemosensing system, the local olfactory environment experienced by a foraging organism is defined as an odorscape. Using the nocturnal pink bollworm moth (Pectinophora gossypiella), we tested the combined effect of three biophysical aspects in its immediate odorscape to shed light on the coupling effects of biotic and abiotic factors on navigation performances of a nocturnal forager: i) the quality of the pheromone source, ii) the pheromone availability, and iii) the airflow characteristics. The navigation performance of the males was investigated using a wind tunnel assay equipped with 3D infrared high-speed cameras. The navigation performance of the males was …
Numerical Study Of Owls' Leading-Edge Serrations, Asif Shahriar Nafi, Nikolaos Beratlis, Elias Balaras, Roi Gurka
Numerical Study Of Owls' Leading-Edge Serrations, Asif Shahriar Nafi, Nikolaos Beratlis, Elias Balaras, Roi Gurka
Physics and Engineering Science
Owls' silent flight is commonly attributed to their special wing morphology combined with wingbeat kinematics. One of these special morphological features is known as the leading-edge serrations: rigid miniature hook-like patterns found at the primaries of the wings' leading-edge. It has been hypothesized that leading-edge serrations function as a passive flow control mechanism, impacting the aerodynamic performance. To elucidate the flow physics associated with owls' leading-edge serrations, we investigate the flow-field characteristic around a barn owl wing with serrated leading-edge geometry positioned at 20° angle of attack for a Reynolds number of 40 000. We use direct numerical simulations, where …
Numerical Study Of Owls’ Leading-Edge Serrations, Asif Shahriar Nafi
Numerical Study Of Owls’ Leading-Edge Serrations, Asif Shahriar Nafi
Electronic Theses and Dissertations
The silent flight ability of owls is often attributed to their unique wing morphology and its interaction with their wingbeat kinematics. Among these distinctive morphological features, leading-edge serrations stand out – these are rigid, miniature, hook-like patterns located at the leading edge of the primary feathers of their wings. It had been hypothesized that these leading-edge serrations serve as a passive flow control mechanism, influencing the aerodynamic performance and potentially affecting the boundary layer development over the wing, subsequently influencing wake flow dynamics. Despite being the subject of research spanning multiple decades, a consensus regarding the aerodynamic mechanisms underpinning owls’ …
Aerodynamics And Turbulent Wake-Flow Characteristics Of Owls During Flapping Flight, Krishnamoorthy Krishnan
Aerodynamics And Turbulent Wake-Flow Characteristics Of Owls During Flapping Flight, Krishnamoorthy Krishnan
Electronic Theses and Dissertations
Owls exhibit unique flight capabilities in the low Reynolds number flow regime which is prone to complex viscous flow phenomena. They possess unique feather features and flexible wing structures which are postulated to help them fly nearly silently and stably at low speeds in a complex flow setting. Understanding the aerodynamics of owls could pave the way to enhance the future designs of small flying vehicles. Though it has been a focus of research over multiple decades, no conclusive agreement has been attained on the aerodynamic mechanisms associated with owl flight. Particularly, the aerodynamics of flapping owl flight is severely …
Characterization Of A Turbulent Boundary Layer In Open Channel Flow Using Particle Image Velocimetry, Mathew James Stanek
Characterization Of A Turbulent Boundary Layer In Open Channel Flow Using Particle Image Velocimetry, Mathew James Stanek
Electronic Theses and Dissertations
Turbulent boundary layers are influential in numerous applications (e.g. naval architecture, ocean engineering, sediment transport, etc.), yet considerable knowledge gaps still exist. Boundary layers are regions where transfer of mass, momentum, energy, and heat occur within the interface between a fluid and a solid, or between two fluids. Utilization of optical flow measurement techniques to measure the velocity field with high spatial resolution enables non-intrusive investigation of the complex fluid dynamics of boundary layers. In this study two-dimensional Particle Image Velocimetry was employed to investigate, primarily, the overlap layer of a turbulent boundary layer developed in the recirculating flume facility …