Numerical simulation of air flow around multiple objects using the discrete vortex method.
J Wind Eng Ind Aerodyn 1995 May; 56(2-3):213-234
Discrete vortex models were developed to solve the two dimensional Navier/Stokes equations for time dependent air flow around circular cylinders. A uniform free stream was assumed in each case. The boundary integral equation and fast multipole expansion algorithm were implemented to make the method feasible for complex flow problems. The flow patterns and Strouhal numbers from the models showed excellent agreement with experimental results. Moreover, the theoretical results showed the possibility of making the discrete vortex method more feasible for engineering problems by using a more flexible and faster potential solver (the boundary integral equation method), and a fast summation method (the fast adaptive multipole expansion method). A situation was designed to simulate a person working on an obstacle in a uniform free stream such as found in a booth exhaust hood. Two different free stream directions were examined to evaluate the effect of changing worker position and possible exposure to job related pollutants. A strong recirculating flow downstream of the worker may lead to high exposure when the contaminant source is located between the worker and workplace, such as a spray paint operation. A different orientation reduced exposure. The authors conclude that discrete vortex methods for solution of time dependent velocity field hold promise for indoor air pollution problems, worker exposure simulations, and contaminant reentry into buildings. In each case, boundary layer separation is the fluid phenomenon of interest, which is captured by the vortex approach.
NIOSH-Grant; Control-technology; Analytical-models; Computer-models; Mathematical-models; Air-flow; Air-contamination; Air-quality
Environmental Sciences & Engr University of North Carolina CB 7400 Rosenau Chapel Hill, NC 27599-7400
Journal of Wind Engineering and Industrial Aerodynamics
University of North Carolina Chapel Hill, Chapel Hill, North Carolina