A model of the atmospheric convective boundary layer (CBL) is realized in the thermally stratified wind tunnel of the Institute of Hydrology and Water Resources, University of Karlsruhe. Further experimental results from this model are presented. The wind tunnel with a test section 10 m long, 1.5 m wide, and 1.5 m high allows one to generate a quasi-stationary, horizontally evolving CBL, charac...

The power generated by a wind turbine largely depends on the wind speed. During time periods with identical hub-height wind speeds but different shapes to the wind profile, a turbine will produce different amounts of power. This variability may be induced by atmospheric stability, which affects profiles of mean wind speed, direction and turbulence across the rotor disk. Our letter examines turb...

Observed upper air soundings that occurred within 2 h and 167 km of derechos were collected and analyzed to document atmospheric stability and wind shear conditions associated with long-lived convective windstorms. Sixty-seven derechos, accompanied by 113 proximity soundings, were identified during the years 1983–93. Owing to the large variability of the synoptic-scale environments associated w...

The recently discovered nonequilibrium turbulence dissipation law implies the existence of axisymmetric turbulent wake regions where the mean flow velocity deficit decays as the inverse of the distance from the wake-generating body and the wake width grows as the square root of that distance. This behavior is different from any documented boundary-free turbulent shear flow to date. Its existenc...

The wind loads considerably influence lightweight spatial structures. An example of spatial structures is scallop domes that contain various configurations and forms and the wind impact on a scallop dome is more complex due to its additional curvature. In our work, the wind pressure coefficient (Cp ) on the scallop dome surface is studied numerically and experimentally. Firstly, the programming...

Large-scale nonlinear simulations of Jupiter's 5-micron hot spots produce long-lived coherent structures that cause subsidence in local regions, explaining the low cloudiness and the dryness measured by the Galileo probe inside a hot spot. Like observed hot spots, the simulated coherent structures are equatorially confined, have periodic spacing, propagate west relative to the flow, are general...

Micro hotlm shear-stress sensors have been developed by using surface micromachining techniques. The sensor consists of a suspended silicon-nitride diaphragm located on top of a vacuum-sealed cavity. A heating and heat-sensing element, made of poly-crystalline silicon material, resides on top of the diaphragm. The underlying vacuum cavity greatly reduces conductive heat loss to the substrate an...