Wind-tunnel study of diffusion and deposition of particles with appreciable settling velocities: annual report

CER84-85MP-JEC48.Includes bibliographical references (page 45).May 1985.Project No. 5-32512.Prepared for Department of the Army, U.S. Army Armament Research and Development Command, Chemical Systems Laboratory, Aberdeen Proving Ground.The deposition on a smooth surface of particles with appreciable settling velocities Vg and small Froude numbers Vg2/gh, where h is the height of the source in a neutrally stable boundary layer, was studied in a meteorological wind tunnel. The measured longitudinal deposition rates of the deposited particles were closely predicted by an approximate model, which relates the deposition rate of settling particle plumes to the diffusion of passive plumes with no reflection from the ground. The lateral dispersion rates of the settling particle plumes were found, however, to be smaller than those of passive plumes

Wind-tunnel research on the mechanics of plumes in the atmosphere surface layer

Includes bibliographical references.Project No. 5-3 2512.Prepared for Department of the Army, U.S. Army Armament Research and Development Command, Chemical Systems Laboratory, Aberdeen Proving Ground.CER83-84JEC-PKS-MP12.The diffusion of a neutrally buoyant gas emitted from point sources into neutral, stable and unstable boundary layers that simulated atmospheric conditions were studied in a meteorological wind tunnel for flow over two surface roughnesses. Measurements were made of the mean flow velocities and temperatures, turbulence intensities, velocity correlations and gas concentrations in the diffusing plume. Empirical models were developed for predicting diffusion under all three stabilities studied

Wind-tunnel simulation of diffusion in an atmospheric surface layer with an elevated inversion: annual report

CER84-85MP-JEC47.Includes bibliographical references (pages 39-40).May 1985.Project No. 5-32512.Prepared for Department of the Army, U.S. Army Armament Research and Development Command, Chemical Systems Laboratory, Aberdeen Proving Ground.Diffusion of neutrally buoyant plumes emitted at various heights within a convective boundary layer capped by an inversion was simulated in a meteorological wind tunnel. Measurements were made of mean and fluctuating velocities and temperatures and of the diffusing plumes. When presented in a dimensionless coordinate system based on the buoyant heat flux and the thickness of the convective layer, the data appear to be consistent with available data from field studies and water-tank simulations and exhibit a unique pattern of diffusion which is related to the nature of the thermals and the downdrafts within the convective boundary layer

Wind forces and moments on microwave antennas

A report to Rose, Chulkoff and Rose.September 1976.CER76-77MP-JEC12.Sponsored by Long Lines Department, American Telephone and Telegraph Company

On the motion of autorotating elongated prismatic bodies

August 1976.CER76-77MP-RNW6.Includes bibliographical references.For National Bureau of Standards under NBS Contract No. 1101-5064-35873

Physical modeling of plumes from cooling-tower emissions, Liquid Air Company, Denver

CER86-87MP-WWL-JAP-JEC2.Includes bibliographical references (page 26).August 12, 1986.CSU Project 2-96780.Sponsored by the Colorado Department of Highways

Study of diffusion from a line source in a turbulent boundary layer

CER62JEC-MP63.October 1962.Includes bibliographical references.Diffusion of a scalar quantity (ammonia gas) from a steady line source within a two-dimensional turbulent boundary layer is studied. Using a long 6 x 6 ft square test section, the boundary-layer thickness varied from 5 to 11 in. for distances of 3 to 43.5 ft downstream with air speeds from 9 to 16 ft/sec. Measurements of mean ammonia concentrations in air are reported, analyzed and compared with a few measurements of heat transfer in similar conditions. Formulation of the results takes into consideration the transverse non homogeneity of the velocity field and also divides the downstream diffusion field into four zones. Measurements of the mean velocity field and the mean concentration field permit the flux of mass in the vertical direction to be calculated through the equation of mass conservation. The use of an eddy diffusivity coefficient to describe the processes of turbulent diffusion is discussed and it is shown that for a long distance downstream of the source, such a coefficient cannot be related to the local Eulerian variables of the boundary-layer flow