建物近傍における汚染物拡散に関する実験的研究 (2)

Abstract

Continued from the preceding paper (1), in this paper (2), I report the results of wind tunnel experiments on the effects of model shape, vent height and so forth on gas diffusion near buildings. Results) C_1′and C_b′become uniform as H/Z_o and W/H become greter (Fig.2-2〜5). 2) The effects of change of h_e/H and u_e/U_H on C_m′and C_w′near a model become small as cavity becomes greater (Fig.2-2〜5, 2-14). 3) When the location of vent is on model's leeward surface, especially when Z_e/H is small, C_1′and C_w′near a model are high and don't become low even if h_e/H increases a little (Fig.2-11, 14, 16). 4) When C_u′in the windward side of vent is higher than C_u′in the leeward side of vent, C′_1 doesn't become low even if h_e/H and u_e/U_H become greater (Fig.2-7, 8). 5) When the location of vent is on model's upper surface, judging from all experimental results, C_1′doesn't exceed 1.17 greately in any case. 6) C_w′in the distance from a model is virtually determined by model shape and H/Z_o (Fig.2-14〜16). 7) When the location of vent is on model's upper surface and D/H is not small, C_1′/C^- and C_w′/C^- near a model are virtually determined by model shape and H/Z_o (Fig.2-13, 17). 8) As Fig.2-22 shows, C_b′isopleth changes complicatedly as X_L/H changes.