Atmospheric Boundary Layer Testing: Experimental Measurements of Heavier-Than-Air Gas Dispersion in an Atmospheric Boundary Layer. 1982-1983 Equipment Loan Report. Supplement 1

摘要

A uniform two-dimensional carbon dioxide gas dispersion in air over a two-dimensional square obstacle was studied experimentally in an atmospheric wind tunnel. The obstacle Reynolds number was about 6000 based upon the undisturbed velocity at the height of the obstacle, and the Froude number was about 1.75. The carbon dioxide was injected vertically upward from the surface at a rate of 10 percent of the freestream velocity. The injection surface area began one obstacle length upstream and extended upstream about 1 1/2 obstacle lengths. A gas concentration measurement system for carbon dioxide mixtures and air was developed for use in an atmospheric wind tunnel. Centerline steady-state concentration profiles were measured for various locations upstream and downstream of the obstacle. The experimental results were compared with the numerical solutions of Sutton (1982). The experiment measurements of concentration were lower than the predicted results of Sutton's numerical solutions, which may be attributed to the higher value of the Froude number in the experimental measurements. (ERA citation 10:032148)