선실내 환기 성능 평가

Abstract

Due to CO2 emission by respiration of crews onboard, ventilation system in cabin is inevitable; however it is very difficult to predict the ventilation performance before it is finally built in. Although the requirements for the ventilation system include air change rate and maximum allowable concentration of CO2 in the cabins, even prototype tests are hardly able to quantify the ventilation performance. In the present paper, a computational method to assess the ventilation characteristics in a cabin is presented by using computational fluid dynamics. The air exchange is modeled by introducing multi-species transport of existing air in the cabin and new air from the ventilation system. Conservation of multi-species as well as 3D Navier-Stokes equation are solved numerically in time dependent manner. Two case of different flow rate are considered. The results include predicted mass fraction of new air in the cabin and the effects of buoyancy due to the skin temperature of crews in the cabin. Due to the lack of experimental data, the computed results are not verified; however, the proposed method can be applied as an assessment tool.