Abstract
Characteristics of turbulence in half-enclosed spaces are investigated in connection with the configuration of the spaces and the representative air velocity. Half-enclosed spaces denote here such spaces as rooms, courtyards, balconies and semiunderground parking spaces etc. which are enclosed with walls, floors and ceilings and partly opened to the outside atmosphere. The air flow in many types of the half-enclosed space are measured using the super-sonic anemometers and the statistical values of turbulence in these spaces are calculated. The relation between these statistical values and the representative air velocity U_0 is shown as below. 1) Turbulence velocity √<u^^-_i^2>=C・U_0…(1) 2) Characteristic time length of turbulence T_i〜U^^-_0…(2) 3) Turbulencecale l_i=constant…(3) 4) Eddy diffusivity K_i〜U^^-_0…(4) Here U^^-_0 : the outlet air velocity into the room or the outside wind velocity C : numerical factor. The numerical factor C in equation (1) is expressed as, C=0.026γ^<0.28>. Here γ is the open-space ratio of the half-enclosed space, defined as the ratio of the total area of openings in the half-enclosed space to the total inside area of the space. The relation between l_i and the space scale L_i is shown as below, l_i=0.07L_i.…(5) As K_i=√<u^^-_i^2>・l_i, the value of K_i can be estimated from equation (1), (5). Namely K_i can be known from U^^-_0 and L_i.
