Characterization of Flow Field in a Multi-Occupant Environment

Abstract

Characterization of flow field in a multi-occupant (cows) ventilated space was conducted using acomputational fluid dynamics (CFD) technique. Airflow in a ventilated space is affected by thelocations of the inlet and outlet and shape and location of the cows. The mathematical modelthat describes airflow in a multi-cow environment involves continuity and momentum equationsas well as a turbulence model. The actual cows configurations are treated as boundaryconditions. The boundary conditions consist of: (1) four cows standing in a row with an inletplaced at one end of the wall and the outlet at the opposite end, (2) four cows standing in a rowwith two inlets placed at opposite ends and an outlet at the center of the ceiling, and (3) ten cowsplaced at random with inlets and an outlet as in Case (2). The body-fitted coordinate (BFC)system is adopted to characterize the shape of the cows, and the governing equations in Cartesiancoordinate system are transformed into the BFC system. To generate the BFC system, partialdifferential equations and algebraic interpolation methods were used. The finite volume methodis applied to transform the partial differential equations into algebraic ones, and the SIMPLE(Semi-Implicit Method for Pressure-Linked Equation) algorithm is extended to the BFC systemto solve the flow field. The calculated results are expressed in velocity vectors, streamline plots,and velocity component profiles.