様々な風向角度の場合の通風気流に関する予測精度検証と流管分析 : LESと風洞実験による建物通風気流構造の解明に関する研究(第2報)

抄録

Airflows of cross-ventilated building model for various wind incident angles were simulated using Large Eddy Simulation, and each calculated flow structure was analyzed to identify the shape of streamtube and mechanism of energy loss of the flow before and after passing through the inflow opening. Simulated results were in good agreement for velocity vectors, wind pressure distributions, etc. and were in fair agreement for cross-ventilation flow rates and pressures at the inflow opening as far as general features depending on wind incident angles are concerned. Approaching flow to the opening tended to form a wall flow immediately before entering the opening and energy loss was almost negligible in this stage unless the flow was separated at the upstream corner of the building. Flow separation occurred in case of the wind incident angles to be 50 degree or more, and turbulent energy production in the region of flow separation was considered as a main source of energy loss before entering the opening. Each pressure loss coefficient of total pressure and cross-ventilation was found to take nearly the same value if the inflow angles were identical irrespective of the incident flow angles.