An Eddy-Viscosity Model Sensitized to Curvature and Wall-Roughness Effects for Reynolds-Averaged Closure

This paper presents a new extension of the realizable K−ε model that accounts for streamline curvature, system rotation, and surface roughness. The model is a type of realizable K−ε model, but the transport equations and the eddy-viscosity damping functions are modified, based on the Richardson number and roughness height; the roughness correction covers both the transitional and fully rough regimes. Flows in a rotating channel and a U-bend duct are used to validate the response of the new model to the system rotation and streamline curvature. The flow in a plane channel and the flow over a dune are used to validate the roughness extension. Finally, a rotating channel with rough walls is studied, to test the new model when both rotation and roughness are present.

Shear piezoelectric properties d24 and k24 of a [001] poled KNNTL-Mn single crystal

The distributions of d24 and k24 in the 3D space of a [001] poled (K, Na, Li)(Na, Ta)O3:Mn (KNNTL-Mn) single crystal were investigated by the coordinate system rotation method.