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...

Title of dissertation: TWO-DIMENSIONAL TURBULENCE WITH DRAG Yue-Kin Tsang, Doctor of Philosophy, 2004 Dissertation directed by: Professor Edward Ott Department of Physics We consider the enstrophy cascade in forced two-dimensional turbulence with a linear drag force. In the presence of linear drag, the energy wavenumber spectrum drops with a power law faster than in the case without drag, and t...

This paper describes and analyzes a series of nearly CFD test cases performed as a contribu tion to the second Drag Prediction Workshop held in association with the AIAA in June Two con gurations are included DLR F wing body and wing body nacelle pylon The ability of CFD to pre dict the drag lift and pitching moment from exper iment including the delta arising from the ad dition of the nacelle ...

Wepresentmeasurements of the dissipative turbulent drag on a vibrating grid in superfluid 4He over awide range of (low) frequencies. At high velocities, the dissipative drag is independent of frequency and is approximately the same as that measured in normal liquid 4He. We present measurements on a similar grid in superfluid 3He-B at low temperatures which shows an almost identical turbulent dr...

We report on an experimental measurement of Coulomb drag in a double quantum well structure consisting of bilayer-bilayer graphene, separated by few layer hexagonal boron nitride. At low temperatures and intermediate densities, a novel negative drag response with an inverse sign is observed, distinct from the momentum and energy drag mechanisms previously reported in double monolayer graphene. ...

In this using paper a method is presented for the aerodynamic and structural analysis of a horizontal axis wind turbine using simplified methods. In the first part of the program the optimum rotor configuration for twist and chord is determined using the momentum and blade element theories for a rotor without coning or tilting and assuming zero drag average wind velocity. Then coning angle and ...

We study theoretically Coulomb drag in capacitively coupled quantum dots (CQDs)-a bias-driven dot coupled to an unbiased dot where transport is due to Coulomb mediated energy transfer drag. To this end, we introduce a master-equation approach that accounts for higher-order tunneling (cotunneling) processes as well as energy-dependent lead couplings, and identify a mesoscopic Coulomb drag mechan...

The practical application of real-time performance optimization is addressed (using a wide-body transport simulation) based on real-time measurements and calculation of incremental drag from forced response maneuvers. Various controller combinations can be envisioned although this study used symmetric outboard aileron and stabilizer. The approach is based on navigation instrumentation and other...

Pressure differences across topography generate a form drag that opposes the flow in the water column, and viscous and pressure forces acting on roughness elements of the topographic surface generate a frictional drag on the bottom. Form drag and bottom roughness lengths were estimated over the East Flower Garden Bank (EFGB) in the Gulf of Mexico by combining an array of bottom pressure measure...