Take-off threshold velocity of saltating particles under heat radiation

Authors

F Pajot
AO el Moctar
P Dupont
H Peerhossaini

Document Type

Article

Publication Date

2002

Journal

EXPERIMENTS IN FLUIDS

Volume

33

Issue

2

First Page

288

URL with Digital Object Identifier

https://doi.org/10.1007/s00348-002-0426-7

Last Page

295

Abstract

A wind tunnel and a heating device were designed in order to study the influence of solar radiation on the wind-induced motion of solid particles. Velocity and temperature measurements in the boundary layer exhibited clear modifications of flow characteristics with a surprising balance between the viscosity increase and the reduction in the wall velocity gradient. This induces a constant critical wall shear stress under heat flux. Measurements of threshold velocity undertaken to elucidate the possible effects of solar radiation through the increase in turbulence intensity showed a reduction in critical free-stream velocity as the free-stream turbulence increased.