Topographic drag schemes depend on grid-scale representations of the average height, width, and orientation of the subgrid topography. Until now, these representations have been based on a combination of statistics and dimensional analysis. However, under certain physical assumptions, linear analysis provides the exact amplitude and orientation of the drag for arbitrary topography. The author p...

Animal momentum and heat transfer analysis has historically used direct animal measurements or approximations to calculate drag and heat transfer coefficients. Research can now use modern 3D rendering and computational fluid dynamics software to simulate animal-fluid interactions. Key questions are the level of agreement between simulations and experiments and how superior they are to classical...

This paper addresses the drag force and formation of vortices in the boundary layer of a Bose-Einstein condensate stirred by a laser beam following the experiments of Phys. Rev. Lett. 83, 2502 (1999)]. We make our analysis in the frame moving at constant speed where the beam is fixed. We find that there is always a drag around the laser beam. We also analyze the mechanism of vortex nucleation. ...

Constant rise in fuel price in recent times has caused manufacturers of heavy commercial vehicles (HCV) to turn to efficient aerodynamic design of trucks, wagons, tractors as well as trailers. The comparative analysis in this study compares the coefficient of drag of the following four aerodynamic configurations of a tractor-trailer combination: 1. Semi-trailer with no devices. 2. Semi-trailer ...

We present a combined experimental and theoretical study of the drag force acting on a high porosity aerogel immersed in liquid (3)He and its effect on sound propagation. The drag force is characterized by the Knudsen number, which is defined as the ratio of the quasiparticle mean free path to the radius of an aerogel strand. Evidence of the Knudsen-hydrodynamic crossover is clearly demonstrate...

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In most cases authors are permitted to post their version of the article (e.g. in Word or Tex form) to their personal website or institutional repository. Authors requiring further information regarding Elsevier's archiving and manuscript policies are encouraged to visit: Abstract A transversely oscillating cylinder in a uniform flow is modeled to investigate frequency effects of flow-induced w...

This study proposes a way to reduce energy losses in the form of rolling resistance friction during manual wheelchair propulsion by increasing the size of the front caster wheels and adjusting the weight distribution. Drag tests were conducted using a treadmill and a force transducer. Three different casters diameter (4 in., 5 in., and 6 in.) and six different mass distribution combinations (ba...

This paper explores differences between user actions employing mouse and touch input devices when performing a collaborative task on a tabletop interface. We explore temporal and spatial characteristics of drag actions of users through mouse (indirect) and touch input (direct) devices. Our analysis is based on system-logged interaction data we collected in an exploratory study. The analysis rev...

Laboratory behavioural observation and computational fluid dynamics (CFD) analysis were conducted to examine whether the movement of the elongated dorsal and pelvic spines changed the hydrodynamic drag in white-streaked grouper Epinephelus ongus larvae. The behavioural observation in the tank revealed that the larvae extended the dorsal and pelvic spines during passive transport and retracted d...