変分法による風速場推定モデルの区画内気流性状解析への応用 - 平行平板間の立方体周りの流れ場における検証

抄録

 This paper describes the evaluation of a diagnostic urban wind model with a future goal of using this method to assess indoor airflow in a cargo space of a pure car carrier (PCC). At present, computational fluid dynamics (CFD) simulation is a popular approach to computing indoor airflow. However, it requires a very long computing time when the simulated flow domain is very large, such as in PCC cargo spaces. In contrast, the diagnostic model is very economical with computer time, so that it can be an appropriate tool for practical use, such as in preliminary design process and ship inspection. Thus, the present study focuses on the application of a Röckle-type diagnostic model to indoor airflow simulation. The Röckle-type approach consists of a mass-consistent flow model and empirical parameterizations for determining initial wind fields disturbed by obstacles. As the first step, the recently modified Röckle model has been applied to the numerical simulation of a flow field over a cube mounted on the lower wall of a plane channel. The results obtained are in reasonably good agreement with experimental and CFD results, except for the vortex size and velocity profile within the recirculation zone formed upstream of the cube. Hence, the empirical parameterizations for the frontal eddy region have been modified to improve the prediction accuracy of mass-consistent final velocity fields. It has been found that for practical simulation the modified Röckle model is a promising approach to quickly compute indoor airflow, though further research is required to confirm its validity and versatility.