Unsteady aerodynamics and flow control for flapping wing flyers

Aerodynamics of Flapping Wing at Low Reynolds Numbers: Force Measurement and Flow Visualization

“…Significant observations have been made in identifying the important governing parameters like Reynolds number (Re) range, advance ratio (J) and phenomena like the leading edge vortex domination [4,8] of these flights hindering the flow separation, wake capture, clap and fling [8], and so on. Based on earlier studies flapping flight can be broadly divided into two categories: quasisteady for J > 1 and unsteady flight for J < 1 [9]. While flights of large birds can be approximately explained using quasisteady theory, the insects' and small bird's flight are highly unsteady.…”

“…While flights of large birds can be approximately explained using quasisteady theory, the insects' and small bird's flight are highly unsteady. Further references of the subject can be obtained from [2][3][4][5][6][7][8][9][10][11][12][13][14][15][16][17].…”

Numerical study on hydrodynamic effect of flexibility in a self-propelled plunging foil

“…Although (passive) flexibility of wing/fin has long been recognized as an important factor in the aerodynamic (hydrodynamic) performance of insect flight or fish swimming, it has received little attention until recently (see [1,2] for a comprehensive review). By using a combination of computational and analytic methods, Daniel and Combes [3] have shown that the deformation in flapping wings was dominated less by aerodynamic loading than by inertial and elastic forces.…”

An experimental study of the effects of pitch-pivot-point location on the propulsion performance of a pitching airfoil

“…There are a large amount of review articles to summarize the research progress of flapping-wing aerodynamics on various aspects (Ho et al, 2003;Platzer et al, 2012;Shyy et al, 2008;Wang, 2005). Knoller (1909) and Betz (1912) were among the first to propose an inviscid theory to explain that a flapping airfoil/wing can generate thrust.…”