| 主权项 |
1. A porous body,
wherein, when
creating porous body data based on an image obtained by a 3-dimensional scan of the porous body, in which porous body data is correlated position information representing position of a pixel in the image, and pixel type information representing whether a space pixel representing that the pixel is space or a matter pixel representing that the pixel is matter,performing a processing of placing, as to the porous body data, one parent virtual sphere having the greatest spherical diameter that can be placed so as to fill in the space pixels without overlapping with the matter pixel, placing at least one child virtual sphere such that the center of the child virtual sphere overlaps with the placed parent virtual sphere and pixels occupied by the child virtual sphere fill in the space pixels without overlapping with the matter pixel, and placing one virtual curved surface solid formed of the parent virtual sphere and the child virtual sphere so as to fill in the space pixels with curved surface solid pixels which are pixels occupied by the virtual curved surface solid, and repeating this processing such that pixels occupied by different virtual curved surface solids do not overlap each other, thereby placing a plurality of the virtual curved surface solids,performing fluid analysis regarding a case of inflow of a fluid from a predetermined inflow face of the porous body by the lattice Boltzmann method based on the porous body data, and thereby deriving a flow velocity vector of the fluid for each space pixel at the time of the fluid passing through the porous body, andderiving a plurality of in-plane uniformity indices γx of flow velocity at a cross-section on the porous body parallel to the inflow face, by the following Expression (1), based on information relating to the placed virtual curved surface solids and information relating to the derived flow velocity vector for each space pixel, and deriving a spatial uniformity index γ of flow velocity at the porous body by the following Expression (2) using the derived in-plane uniformity indices γx;the average value of the plurality of in-plane uniformity indices γx is 0.6 or greater, and the spatial uniformity index γ is 0.6 or greaterγx=1-12∑i=1nui-umean·Aiumean·AExpression(1) where n: number [count] of virtual curved surface solids within cross-section x: distance [m] between cross-section and inflow face ui: average flow velocity (i=1, 2, . . . , n) [m/s] for each of the n virtual curved surface solids at cross-section umean: average value (=(ui+u2+ . . . +un)/n) [m/s] of average flow velocity ui at cross-section Ai: cross-sectional area (i=1, 2, . . . , n) [m2] for each virtual curved surface solid within cross-section A: total cross-sectional area (=A1+A2+ . . . +An) [m2] of virtual curved surface solids at cross-section
γ= γx·(1−δγ) Expression (2) where γx: average value of γx δγ: standard deviation of γxγx=1-12∑i=1nui-umean·Aiumean·AExpression(1) where n: number [count] of virtual curved surface solids within cross-section x: distance [m] between cross-section and inflow face ui: average flow velocity (i=1, 2, . . . , n) [m/s] for each of the n virtual curved surface solids at cross-section umean: average value (=(ui+u2+ . . . +un)/n)[m/s] of average flow velocity ui at cross-section Ai: cross-sectional area (i=1, 2, . . . , n)[m2] for each virtual curved surface solid within cross-section A: total cross-sectional area (=A1+A2+ . . . +An)[m2] of virtual curved surface solids at cross-section
γ= γx·(1−δγ) Expression (2) γx: average value of γx δγ: standard deviation of γx. |
