Enhancement of cross-ventilation of a detached house using roof surfaces in densely populated urban areas? Part 2 Numerical investigations about the effects of the roof surface use by CFD

In Part 1, the changes in wind pressure coefficient distributionon the surfaces of the buildings when building coverage is varied are evaluated and identified, and it is elucidated that the ventilation through skylight is effectivebecause the surfacepressure can bekept negativeon roof surfaces even when building coverage is high.In Part 2, the results of numerical simulation (CFD) are compared with the experimental results. To perform this study, for the purpose of analyzing the configurations such as the roof with gradient, meshbuilding methods based on multi-blocks and layer meshes are proposed to generate calculation meshes in optimal and systematicmanner, and the results of the methods are verified.Further, because the validity of the modeling of urban area in cyclic boundary condition is already reported in previous studies, the case where building coverage of urban area is changed is analyzed by varying the size of the area under computation and by the method to apply cyclic boundary condition, and the results are compared with the results of experiment as described in Part 1 of the study.