抄録
In the present study, in order to clarify the effect of a velocity field formed around a building model on the transport phenomena of a substance, we have experimentally investigated the characteristics of a concentration field with a fastresponse flame ionization detector. An ethylene emission equipment and the building model are installed in a turbulent boundary layer developing on a flat plate. We have elucidated the fluid-dynamical relationship between turbulent diffusion of ethylene and the flow field formed behind the building model by changing the angle of the building model. As a result, the mean velocity field formed behind the building model can strongly affect the mean concentration distribution in cross sections normal to the free-stream direction. Moreover, it is found that the behavior of the rms intensity of the concentration fluctuations can well be characterized by the streamwise turbulence intensity behind the model.
