An analytical, numerical, and experimental comparison of the fluid velocity in the vicinity of an open tank with one and two lateral exhaust slot hoods and a uniform crossdraft

The objective of this research was to compare mathematical models of the fl uid velocity in the vicinity of an open tank with lateral slot exhaust, Two approaches were explored: a numerical solution assuming turbulent flow and an analytical solution assuming potential flow. A numerical simulation of the how field in and around an open surface tank was performed using the co mmercial software FLUENT(R). An analytical solution was obtained using two- dimensional potential fluid how determined using the Schwarz-Christoffel tr ansformation and complex potential theory. The numerical and analytical sol utions were compared with numerical solutions and experimental measurements published by others. The numerical solution using FLUENT and the two numer ical solutions published by others appear to reflect experimental condition s with equal accuracy, In some regions, the FLUENT solution appears better while in other regions the other tno solutions appear better. Differences i n geometry and boundary conditions could explain these differences. Greater differences were observed between the FLUENT and CFX-F3D(TM) solutions tha n between the EOL-2D(TM) and CFX-F3D solutions. This was unexpected since t he geometry, boundary conditions, and turbulence model were more similar in the former case than in the latter. The potential flow solution, while sim pler and less computationally intensive than the numerical solutions, resul ted in estimates of experimental velocity that were equally as good as thos e of the numerical solutions, The simplicity and conservative estimates of this model make it useful for estimating exhaust hood flea fields. (C) 2000 British Occupational Hygiene Society. Published by Elsevier Science Ltd. A ll rights reserved.