FIELD OF THE INVENTION

The present disclosure relates to methods and apparatuses for identifying valid or invalid flow path.

BACKGROUND

Japanese Patent Application Laid-open No. 2015-189666 discloses that, in order to balance smaller porosity in a porous body and higher permeability of the porous body, fluid analysis is performed based on artificial porous body data to calculate information regarding flow velocity in a respective spatial voxel. Japanese Patent Application Laid-open No. 2015-189666 discloses that a priority is placed to replace spatial voxels presenting a lower flow velocity with solid voxels so that a target value of porosity is achieved.

Japanese Patent Application Laid-open No. 2013-53589 discloses that pore diameters are observed based on a SEM image with respect to a wall-flow-type exhaust gas purification filter (See FIG. 4 of Japanese Patent Application Laid-open No. 2013-53589).

SUMMARY

The present inventors have newly identified a benefit of distinguishing, from other flow paths, valid flow paths that allow a fluid to flow from an inflow surface to an outflow surface, enabling more precise evaluation of performance of the porous body.

A method according to an aspect of the present disclosure may include: performing fluid analysis of a porous body, which is ought to have inflow surface and outflow surface, based on structure data representing a 3-dimentional structure of the porous body to generate data indicating at least a pressure distribution of a fluid in a flow path in the porous body; and identifying a valid flow path that allows the fluid to flow from the inflow surface to the outflow surface based on a gradient of pressure values along a flow direction of the fluid in the flow path.

In some cases, the valid flow path is identified based on plural isobaric surfaces that have different pressure values along the flow direction of the fluid in the flow path.

In some cases, a cross-sectional area of the valid flow path is determined based on the isobaric surface.

In some cases, a volume of the valid flow path is determined based on the isobaric surfaces.

In some cases, a partial volume of the valid flow path is determined based on, at least, a distance between first and second isobaric surfaces in the flow direction of the fluid and an area of the first and/or second isobaric surface.

In some cases, the method further includes determining a ratio of a sum of respective cross-sectional areas of the valid flow paths in a given cross-section of the porous body to a sum of respective cross-sectional areas of pores in the given cross-section of the porous body.

In some cases, the method further includes determining a ratio of a volume of the valid flow path to a total volume of pores in the porous body.

In some cases, the method further includes determining a ratio of a sum of cross-sectional areas of the valid flow paths in a given cross-section of the porous body to a sum of cross-sectional areas of both of pores and ceramics portions in the given cross-section of the porous body.

In some cases, the method further includes determining a ratio of a volume of the valid flow path to a volume of the porous body.

In some cases, the method further includes determining an equivalent diameter of the isobaric surface based on an area and a perimeter length of the isobaric surface.

In some cases, the method further includes determining a distribution of equivalent diameters.

In some cases, the method further includes determining a distribution of the number of the isobaric surfaces having equivalent diameters of the same value or within the same numerical range.

In some cases, said data also indicates a distribution of flow velocity of the fluid flowing through the flow path, and the method further includes determining a flow rate of the fluid passing an isobaric surface in a given time window based on a flow velocity indicated by said data and an area of the isobaric surface in which equal pressure values are distributed so as to cross the flow direction of the fluid in the valid flow path.

In some cases, the method further includes determining a flow rate of the fluid flowing through a part of or an entirety of the valid flow paths in the porous body based on a sum of the flow rates determined for the respective isobaric surfaces.

In some cases, the method further include determining, for the isobaric surface, an evaluation value regarding filtering characteristic based on the flow rate determined for the isobaric surface.

In some cases, the structure data is a 3-dimentional set of voxels that have digital values.

In some cases, the method further includes setting lattice points to the structure data, and wherein a distance between isobaric surfaces that have different pressure values along the flow direction of the fluid in the flow path includes a distance that is less than a lattice interval in the structure data.

An apparatus according to an aspect of the present disclosure may be configured to: perform fluid analysis of a porous body, which is ought to have inflow surface and outflow surface, based on structure data representing a 3-dimentional structure of the porous body to generate data indicating at least a pressure distribution of a fluid in a flow path in the porous body; and identify a valid flow path that allows a fluid to flow from the inflow surface to the outflow surface based on a gradient of pressure values along a flow direction of the fluid in the flow path.

A method according to an aspect of the present disclosure may include: performing fluid analysis of a porous body, which is ought to have inflow surface and outflow surface, based on structure data representing a 3-dimentional structure of the porous body to generate data indicating at least a pressure distribution of a fluid in a flow path in the porous body; and identifying an invalid flow path that does not allow the fluid to flow from the inflow surface to the outflow surface based on a set of pressure values within a given numerical range indicating no flow of the fluid in the flow path.

An apparatus according to an aspect of the present disclosure may be configured to: perform fluid analysis of a porous body, which is ought to have inflow surface and outflow surface, based on structure data representing a 3-dimentional structure of the porous body to generate data indicating at least a pressure distribution of a fluid in a flow path in the porous body; and identify an invalid flow path that does not allow the fluid to flow from the inflow surface to the outflow surface based on a set of pressure values within a given numerical range indicating no flow of the fluid in the flow path.

According to an aspect of the present disclosure, valid flow paths that allows a fluid to flow from an inflow surface to an outflow surface and/or invalid flow paths that does not allow a fluid to flow from an inflow surface to an outflow surface may be identified.

