6 results about "Particle radius" patented technology

The invention discloses a method for constructing a three-dimensional digital core model of irregular concave-convex particles, and the method comprises the following steps: S1, generating regular small balls with the same radius distribution based on the radius distribution and shape characteristics of actual rock particles; s2, constructing a single particle with an irregular concave-convex shape based on a single regular small ball; s3, by setting modeling parameters of different regular small balls, on the basis of a construction method of a single particle with an irregular concave-convex shape, constructing a plurality of irregular concave-convex particles by the regular small balls with different sizes; and S4, simulating deposition and compaction diagenesis processes of a plurality of irregular concave-convex particles in a three-dimensional space to obtain digital core models with different pore structures. The modeling principle and process have the advantages of being easy to understand, controllable in concave-convex shape, diverse in result and the like, and a model foundation is laid for oil and gas reservoir rock physical analysis and modeling work.

The invention relates to the field of multiphase numerical simulation, and discloses a cross-scale particle flow calculation method based on feature point arrangement, and the method comprises the steps: obtaining the position coordinates, speed, radius and augmentation coefficient of particles in a current time step, and the position coordinates, volume and speed of all fluid domain grids; determining position coordinates of the feature points according to the grid volume, the particle radius and the augmentation coefficient; dividing grids where the feature points are located into internal grids, boundary grids and external grids on the basis of the position relationship between the feature points and the particles, calculating the voidage of each grid in different modes, and calculating the background voidage of the particles; the background flow field speed of the particles is calculated according to the grid voidage, the volume and the speed; according to the background voidage, the speed and the background flow field speed of the particles, the drag force borne by the particles is calculated, and therefore numerical calculation of the cross-scale particles is achieved.

The application discloses a method for constructing a three-dimensional digital core model of irregular concave-convex particles, and comprises the following steps: S1, generating regular small balls with the same radius distribution based on the actual rock particle radius distribution and shape characteristics; S2, constructing a single particle with irregular concave-convex shape based on a single regular small ball; S3, constructing several regular small balls with different sizes into several irregular concave-convex particles by setting the modeling parameters of different regular small balls based on the construction method of the single particle with irregular concave-convex shape; and S4, simulating the deposition and compaction of the several irregular concave-convex particles in a three-dimensional space to obtain a digital core model with different pore structures. The modeling principle and process of the application have the advantages of easy understanding, controllable concave-convex shape, various results and the like, and lay a model foundation for carrying out oil and gas reservoir petrophysical analysis and modeling work.

The application relates to the field of multiphase numerical simulation, and discloses a cross-scale particle flow calculation method based on feature point arrangement, which comprises the following steps: acquiring the position coordinates, velocity, radius and augmented coefficient of a particle at a current time step, and the position coordinates, volume and velocity of all fluid domain grids; determining the position coordinates of feature points according to the grid volume, particle radius and augmented coefficient; dividing the grid where the feature points are located into an internal grid, a boundary grid and an external grid based on the position relationship between the feature points and the particles, calculating the void fraction of each grid in different ways, and obtaining the background void fraction of the particles; calculating the background flow field velocity of the particles according to the grid void fraction, volume and velocity; and calculating the drag force suffered by the particles according to the background void fraction, velocity and background flow field velocity of the particles, so as to realize numerical calculation of cross-scale particles.

This invention discloses a method for constructing a microscopic numerical model of granular flow that considers stress field distribution characteristics. It relates to the field of microscopic numerical simulation in geotechnical engineering. The method uses AutoCAD to construct the boundary and generate a continuous numerical grid. Particles are then deployed one by one using element domain control. The self-weight stress of the particles is considered. By combining the addition of particles and the change of particle radius, the particle system is made to tightly bond together, thereby forming a dense slope microscopic feature with controllable coordination number and mechanical properties that gradually increase from the surface to the interior. This ensures that the microscopic particle model fills the entire modeling range under the stress field distribution conditions, thus ensuring the accuracy of the microscopic geometric dimensions.

Methods for specimen preparation and for characterization of internal three-dimensional deformation of specimen are provided. Firstly, a plurality of first digital particle models are generated, and a plurality of first volumetric images are generated based on central point positions of the speckle particles simulated by each first digital particle model of the plurality of first digital particle models. A simulated optimal particle radius value and a simulated optimal volume fraction value corresponding to speckle particles included in a target specimen are determined based on all the first volumetric images. Finally, the target specimen may be prepared based on the simulated optimal particle radius value and the simulated optimal volume fraction value corresponding to the speckle particles included in the target specimen. The plurality of first digital particle models generated through numerical simulation are processed and calculated to obtain distribution parameters of the speckle particles in the target specimen.