This work was motivated by subtidal observations of red urchins (Strongylocentrotus franciscanus) moving their spines into streamlined positions as water current increased in the field. Trials in a flume across flow speeds from 0 to 65 cm s(-1) enabled us to observe the change in overall shape of the urchins and quantify the decrease in spine angle that occurred as flow speeds increased. The ef...

A computational study was conducted to better understand experimental results obtained from wind tunnel tests of a Mach 4 waverider model and a comparative reference configuration. The experimental results showed that the performance of the reference configuration was slightly better than that of the waverider model. These results contradict waverider design theory, which suggests that a waveri...

A prominent feature of gliding flight in snakes of the genus Chrysopelea is the unique cross-sectional shape of the body, which acts as the lifting surface in the absence of wings. When gliding, the flying snake Chrysopelea paradisi morphs its circular cross-section into a triangular shape by splaying its ribs and flattening its body in the dorsoventral axis, forming a geometry with fore-aft sy...

At transonic flight conditions, the buffet caused by interaction between shock waves and boundary layers can degrade an aircraft’s aerodynamic performance even threaten its safety. In this paper, control bumps, originally designed to reduce wave drag at cruise speeds, are applied enhance robustness of closed-loop system using trailing-edge flap. For OAT15A supercritical airfoil, a is first with...

Chrysopelea paradisi, also known as the flying snake, possesses one of the most unique forms of aerial locomotion found in nature, using its entire body as a dynamic lifting surface without the use of wings or membranes. Unlike other airborne creatures, this species lacks appendages to aid in controlling its flight trajectory and producing lift. The snake exhibits exception gliding and maneuver...

A slot formed between the slat and main wing of 2D high-lift device is used to accelerate convergence flow upper surface improve field quality. In order further enhance characteristics, this paper proposes a design method for multi-channel leading-edge slats based on grid channels. On one hand, specific shape shrinking expansion tube lift characteristics leading slat. other newly plays similar ...

To improve knowledge of the wind loads on photovoltaic structures mounted on flat roofs at the high angles required in high latitudes, and to study starting flow on low aspect ratio wind turbine blades, a series of wind tunnel tests were undertaken. Thin flat plates of aspect ratios between 0.4 and 9.0 were mounted on a sensitive three-component instantaneous force and moment sensor. The Reynol...

The growing interest in micro aerial vehicles has brought attention to the need for an improved understanding of the aerodynamics of low-aspect-ratio wings at lowReynolds numbers. In this study, flat plate wings with rectangular and tapered planforms were fabricated with aspect ratios of 0.75, 1, 1.5, and 3, and the aerodynamic loading was measured at Reynolds numbers between 5 10 and 1 10. Sur...

Recently, experiments showed that forces on intruders dragged horizontally through dense, hydrostatic granular packings mainly depend on the local surface orientation and can be seen as the sum of the forces exerted on small surface elements. In order to understand such forces more deeply, we perform a two-dimensional soft-sphere molecular dynamics simulation, on a similar setup, of an intruder...

A sweep process of a wing is very useful technique to enhance an aircraft performance especially the which fly in sonic and supersonic areas. In this research, influence swept on aerodynamic characteristics generation at speeds has been studied analyzed using CFD technique. The 3D model presented paper NACA 2412 profile. governing equations such as continuity, Energy Equation, Reynolds Averagin...