We used a dynamically scaled mechanical model of the fruit fly Drosophila melanogaster to study how changes in wing kinematics influence the production of unsteady aerodynamic forces in insect flight. We examined 191 separate sets of kinematic patterns that differed with respect to stroke amplitude, angle of attack, flip timing, flip duration and the shape and magnitude of stroke deviation. Ins...

Abstract With the purpose of investigating effects geometry parameters CFJ (Coflow jet) device on aerodynamic characteristics supercritical bacj airfoil used by a STOL transport, we have carried out computational analysis with different values injection slot size and location under low-speed condition. The results show that lift coefficient decreases gradually decreasing stall angle, when is in...

Wing-motion of hovering small fly Liriomyza sativae was measured using high-speed video and flows of the wings calculated numerically. The fly used high wingbeat frequency (≈265 Hz) and large stroke amplitude (≈182°); therefore, even if its wing-length (R) was small (R ≈ 1.4 mm), the mean velocity of wing reached ≈1.5 m/s, the same as that of an average-size insect (R ≈ 3 mm). But the Reynolds ...

We identify a quantum lift of the greedy basis for rank 2 coefficient-free cluster algebras. Our main result is that our construction does not depend on the choice of initial cluster, that it builds all cluster monomials, and that it produces bar-invariant elements. We also present several conjectures related to this quantum greedy basis and the triangular basis of Berenstein and Zelevinsky.

We examine Weyl groups of minimal connected simple groups of finite Morley rank of degenerate type. We show that they are cyclic, and lift isomorphically to subgroups of the ambient group.

The flow mechanism leading to the enhanced performance of a discrete co-flow jet (dCFJ) airfoil is investigated. Flow visualization and DPIV are used to analyze the difference between the flow along discrete jets and over the tabs used for discretization of the slot jet. Results show that the entrainment is uniform over the leading jet as long as the tab size is small enough. The jets expand sp...

The adjoint-based sensitivity analyses well explored in hydrodynamic stability studies are extended to calculate the sensitivity of forces acting on an aerofoil with respect to wall transpiration. The magnitude of the sensitivity quantifies the controllability of the force, and the distribution of the sensitivity represents a most effective control when the control magnitude is small enough. Si...

A linear vortex panel method is extended to include the effect Abstract of ground proximity on the aerodynamic properties of two dimensional airfoils. The image method is used to model the ground effect . According to the results, lift coefficient of an airfoil may increase or decrease in ground effect based on a combinative effect of its camber, thickness, angle of attack and ground clearance....