相关论文: On the maintenance of an attached leading-edge vor…

The leading edge vortex (LEV) is one of the most important lift augmentation mechanisms in flapping wing aerodynamics. We propose a methodology that aims to provide a quantitative description of the LEV. The first step of the method…

Several previous experimental and theoretical studies have shown that a leading edge vortex (LEV) on an airfoil or wing can provide lift enhancement. In this paper, unsteady 2D potential flow theory is employed to model the flow field of a…

Birds have a remarkable ability to perform complex maneuvers at post-stall angles of attack. The passive deployment of self-actuating covert feathers in response to unsteady flow separation while performing such maneuvers provides a passive…

The wing structure of several insects, including dragonflies, is not smooth, but corrugated; its vertical cross-section consists of a connected series of line segments. Some previous studies have reported that corrugated wings exhibit…

This study examines flow over a cranked {\lambda}-wing model with a sweep of {\Lambda}=60{\deg} of the inboard leading edge (LE) that changed to {\Lambda}=30{\deg} outboard of the crank. The study focuses on the liftoff of the inboard…

Flapping wing propulsion offers unrivalled manoeuvrability and efficiency at low flight speeds and in hover. These advantages are attributed to the leading edge vortex developing on an unsteady wing, which induces additional lift. We…

This study presents a novel spatially disrupted flow control system inspired by the covert feathers on bird wings. The system is a passive flow control system consisting of multiple feather-inspired flaps that dynamically interact with the…

Hummingbirds and insects achieve outstanding flight performance by adapting their flapping motion to the flight requirements. Their wing kinematics can change from smooth flapping to highly dynamic waveforms, generating unsteady aerodynamic…

While dragonflies are highly agile flyers, some key aerodynamic mechanisms responsible for their flight performance remain inadequately understood. Based on forward flight conditions, we investigate dragonfliess spanwise aerodynamic…

The present study is a prelude to applying different flow control devices on pitching and plunging airfoils with the intention of controlling the growth of the leading edge vortex (LEV); hence, the lift under unsteady stall conditions. As a…

The Anthena Vortex Lattice (AVL) [1] program describes aerodynamic and flight-dynamic analysis of rigid aircraft of arbitrary configuration and we use it to analyse the stability modes of a Boeing 737-800 under various small perturbations…

Airborne insects generate a leading edge vortex when they flap their wings. This coherent vortex is a low pressure region that enhances the lift of flapping wings compared to fixed wings. Insect wings are thin membranes strengthened by a…

Compared with fixed-wing flight, flapping flight can generate a higher lift and is also more maneuverable, largely resulting from the benefits of wing rotation. By analyzing the real wing kinematics of fruit flies, we found that the wing…

The transition of the vortex pattern and the lift generated by a heaving wing in a uniform flow was investigated numerically. Motivated by insects' flight maneuverability, we studied the relationship between a temporal change in the heaving…

This work investigated the vorticity dynamics and stability of leading-edge vortices (LEVs) in revolving wings. Previous studies suggested that Coriolis acceleration and spanwise flow both played key roles in stabilizing the LEV; however,…

Rotation has been recognized for its ability to decrease the extent of separate flow regions on the inner sections ofhorizontal-axis wind turbine blades. This alteration is often linked to centrifugal pumping. Nevertheless, studies focused…

Hovering insects are limited by their physiology and need to rotate their wings at the end of each back and forth motion to keep the wing's leading edge ahead of its trailing edge. The wing rotation at the end of each half-stroke pushes the…

Unsteady inviscid flow models of wings and airfoils have been developed to study the aerodynamics of natural and man-made flyers. Vortex methods have been extensively applied to reduce the dimensionality of these aerodynamic models, based…

We report direct numerical simulations of a pair of wings in horizontal tandem configuration, to analyze the effect of their aspect ratio on the flow and the aerodynamic performance of the system. The wings are immersed in a uniform…

Stall cells are spanwise-periodic flow structures that spontaneously form on airfoils operating near stall, fundamentally altering the aerodynamic loading distribution. Despite decades of experimental observations, a complete theoretical…