Lofting of Particulates by a High Speed Wind
APPLIED THEORY INC LOS ANGELES CA
Pagination or Media Count:
Wind tunnel studies of particulate lofting were conducted at free stream speeds of between 112 and 376 fps. Measurements were made of the rate at which particulates were lofted, of the wind velocity profile and of the number density of airborne particulates. The measurement bearing the most practical significance was that of the lofting rate the measured lofting rate was only 1 10 that of the maximum rate predicted by current theory, although the lofting rate was found to be directly proportional to the shear stress velocity in accord with the theory. The velocity profile within the boundary layer but at heights greater than the effective roughness created by the particulate flow is of the form given by Prandtls law for flow past a wall. Boundary layer calculations in conjunction with the measurements show that Owens form for the flow law cannot hold near the head of the boundary layer.