A large eddy simulation (LES) code of the atmospheric boundary layer (ABL) has been developed and applied to study the effect of spatially variable surface properties on the areally averaged surface shear stress at the land-atmosphere interface. The LES code simulates the space and time evolution of the large-scale turbulent eddies and their transport effects in the ABL. We report here on simul...

There has been an increasing attention to the effect of hull roughness on ship resistance and powering. In conventional studies, surfaces have treated as uniform rough while real ships' hulls are exposed heterogeneous fouling accumulation. The work described here presents experimental investigation into resistance. A series towing tests were conducted using a model Wigley with various condition...

To evaluate the adaptive value of the widening of the bilobed tarsi that has paralleled the tremendous radiation of the staphylinid genus Stenus, the performance of slender versus wide tarsi has been evaluated in two different contexts: (i) locomotion on the surface of water, and (ii) climbing on vertical (plant) surfaces. Contact angle measurements at the underside of the tarsi have revealed t...

The benefits of synthetic fibrillar dry adhesives for temporary and reversible attachment to hard objects with smooth surfaces have been successfully demonstrated in previous studies. However, surface roughness induces a dramatic reduction in pull-off stresses and necessarily requires revised design concepts. Toward this aim, we introduce cylindrical two-phase single pillars, which are composed...

The surface characteristics, such as wettability and roughness, play an important role in heat transfer performance in the field of microfluidic flow. In this paper, the process of a hot liquid flowing through a microchannel with cold walls, which possesses different surface wettabilities and microstructures, is simulated by a transient double-distribution function (DDF) two-phase thermal latti...

Colony morphology has been used as an important identification and characterization criterion in bacteriology for many decades. However, the molecular mechanisms underlying the appearance of different colony types have been given little attention. The synthesis of O antigen is defunct in Escherichia coli K-12, and colonies should accordingly only appear to be rough. However, previous reports ha...

The irregularities on trains bodies are normally ignored or greatly simplified in studies concerned with aerodynamics. However, surface roughness is known to affect the flow characteristics boundary layer near wall, hence potentially influencing aerodynamic performance of a train. This work investigates effects overall high-speed train subjected crosswinds. Both experimental and numerical have ...

The importance of early tactile experience in the development of discriminative somatomotor function was assessed by examining the proficiency and movement strategies of rats raised without normal sensory inputs provided by their mystacial vibrissae. Infant-trimmed animals had their whiskers clipped daily from birth to 45 d of age, after which they were allowed to regrow for 60-70 d before init...

Metal additive manufacturing has enabled geometrically complex internal cooling channels for turbine and heat exchanger applications, but the process gives rise to large-scale roughness whose size is comparable channel height (which 500 $\mathrm {\mu }$ m). These super-rough pose previously unseen challenges experimental measurements, data interpretation modelling. First, it not clear if measur...