The Green's function approach of Giles and Pierce ( J. Fluid Mech. , vol. 426, 2001, pp. 327–345) is used to build the lift drag based analytic adjoint solutions for two-dimensional incompressible Euler equations around irrotational base flows. drag-based solution turns out have a very simple closed form in terms flow variables smooth throughout domain, while lift-based singular at rear stagnat...

In the present world, passive control finds application in various areas like flow over blunt projectiles, missiles, supersonic parallel diffusers (for cruise correction), engine of jets, static testbeds rockets, ports internal combustion engines, vernier and single expansion ramp nozzle (SERN) rockets. this review, techniques to base pressure regulate drag force are discussed. study, papers ra...

The aim of this study was to compare the swimming hydrodynamics assessed with experimental and analytical procedures, as well as, to learn about the relative contributions of the friction drag and pressure drag to total passive drag. Sixty young talented swimmers (30 boys and 30 girls with 13.59±0.77 and 12.61±0.07 years-old, respectively) were assessed. Passive drag was assessed with inverse d...

PREMISE OF THE STUDY Intertidal macroalgae must resist extreme hydrodynamic forces imposed by crashing waves. How does frond flexibility mitigate drag, and how does flexibility affect predictions of drag and dislodgement in the field? METHODS We characterized flexible reconfiguration of six seaweed species in a recirculating water flume, documenting both shape change and area reduction as fro...

Tests have been made at a Mach number of 4.03 and Reynolds number of 3'4 million on two families of models, consisting of delta wings with underslung half-Cone bodies. The wing sweepback angles were 75 ° and 80 °, and the appropriate cone semi-vertex angles tested were 4 °, 10 ° and 13 ° for the larger wing and 4 °, 6"7 ° and 10 ° for the smaller wing. The surface distributions were measured at...

Aerodynamic drag force breakdown of a typical transport aircraft shows that lift-induced drag can amount to as much as 40% of total drag at cruise conditions and 80-90% of the total drag in take-off configuration. One way of reducing lift-induced drag is by using wing-tip devices. By applying several types of winglets, which are already used on commercial airplanes, we study their influence on ...

In Coulomb drag, a current flowing in one conductor can induce a voltage across an adjacent conductor via the Coulomb interaction. The mechanisms yielding drag effects are not always understood, even though drag effects are sufficiently general to be seen in many low-dimensional systems. In this Letter, we observe Coulomb drag in a Coulomb-coupled double quantum dot and, through both experiment...