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. ...

Spanwise wall oscillations alter the organization of low-speed streaks and ejections in turbulent boundary layers, eventually leading to skin friction drag reduction. Such flow regimes are represented by pointwise statistics or spatial correlation. This work attempts quantify systematic distortions dominant structures feature-analysis, intended overcome dispersion observed correlation functions...

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...

A procedure for tailoring a blended wing-body con guration to reduce its computed wave drag is described. The method utilizes an iterative algorithm within the framework of rst-order linear theory. Four computed examples are included. In each case, the zero-lift wave drag was reduced without an increase in drag due to lift. Introduction In the initial rough-cut state of supersonic conguration d...

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...

We show that Coulomb drag in bilayer systems the regime of electron hydrodynamics leads to additional viscosity terms hydrodynamic equations, drag, and drag-Hall viscosities, besides well-known kinematic Hall viscosities. These arise from a change stress tensor due interlayer interactions. All four are tunable by varying applied magnetic field densities two layers. At certain ratios between lay...

The main resistive force in swimming is due to drag on a swimmer’s body from the water. There are two forms of drag, one is active drag (FD), which is the drag encountered while propelling the body through the water. The other is passive drag or the drag encountered while gliding during a push-off after a turn or after entering the water from the start. These different types of drag are both pr...