Development of Cold Draft Prevention System Utilizing the Momentum of Airflow along the Window

室内部分周边容易受到室外的影响，冬季可能出现冷风。本研究旨在开发一种可避免在靠近窗户的周边产生气流的设备，其过程分为三个步骤：1）模拟与实验的比较，2）通过模拟设计设备的尺寸，3）将其应用于实际房间进行验证。1）二维模拟与具有线气流供应的全尺寸实验一致，2）通过模拟预期高性能的设备在冬季安装在1F的教室和2F的角落中，3）三维模拟结果与实验结果基本一致，但还需要进行更精确的实验; 4）对气流的抑制效果，产热率最好，其次是设备进出口宽度，在此基础上，对该装置进行了结构设计和性能验证。即使当发热率为通过窗户的热损失的70%时，系统也可以避免通风。

The part of perimeter in rooms are likely to have the effect of outdoor and the cold draft can occur in winter. This research is aimed to develop the equipment which avoid the draft at the perimeter close to the window.The procedure takes three steps ; 1) the comparison between the simulation and the experiment, 2) the design of the dimension of the equipment by the simulation, and 3) the validation with applying it to actual rooms.The results show ; 1) the 2-dimensional simulation agrees with the full scale experiment that has the line airflow supply, 2) the equipment that is expected high performance by the simulation is installed in a classroom at 1F and a corner at 2F in winter, and the measurement indicates that the equipment prevent the draft, 3) the 3-dimensional simulation shows same flow pattern to the measurement but more precise experiment may be necessary, and 4) the heat generation rate is most effective to avoid the draft and the width of inlet and outlet of the equipment is next, where the width should be more than the thickness of boundary layer developed by the draft.As a summary the equipment is constructed and the performance is confirmed. The system avoid the draft even when the heat generation rate is 70% of the heat loss through the window.