NUMERICAL CALCULATION OF FLOW AND STACK GAS CONCENTRATION FLUCTUATION AROUND A MESHED TRUSS CUBICAL BUILDING

摘要

Concentration fluctuation of stack gas around a meshed truss cubical building is calculated. Stack gas is emitted continuously from the roof of the building. The meshed truss cubical building simulates a building composed of many pipes and structures. The flow field is calculated using large eddy simulation. Concentration is calculated using large eddy simulation and the puff method, in which small volumes of the tracer gas are divided and combined according to the calculation mesh size. In order to avoid numerical viscous effects, the puff method is applied in the regions near to the stack. Obtained flow and concentration calculation results are compared with those of the wind tunnel. Though disagreement for mean, concentration fluctuation intensity and peak concentration is observed, the regions in which the disagreement is observed are restricted; otherwise, good agreement with those obtained by the wind tunnel experiment is obtained.