Streakline visualization apparatus and method

Patent metadata

Field	Value
Publication number	US-10799191-B2
Application number	US-201715827579-A
Country	US
Kind code	B2
Filing date	Nov 30, 2017
Priority date	Dec 6, 2016
Publication date	Oct 13, 2020
Grant date	Oct 13, 2020

Abstract

In a streakline visualization apparatus, a processing unit calculates, by using an expression including a correction value for correcting an error attributable to accelerated motion of a plurality of grid points represented by position information, time differential values of velocities of fluid on the plurality of grid points at each of the plurality of first time points. The processing unit calculates, based on the velocities and the time differential values of the velocities of the fluid on the plurality of grid points at each of the plurality of first time points, positions of a series of a plurality of particles sequentially outputted from a particle generation source as analysis time progresses at each of a plurality of second time points having a second time interval shorter than the first time interval. The processing unit generates display information about a streakline indicating the series of the plurality of particles.

First claim

What is claimed is:

1. A streakline visualization apparatus comprising:
a memory configured to store fluid information including position information indicating positions of a plurality of grid points that move with accelerated motion in an analysis space as analysis time of a fluid simulation progresses, at each of a plurality of first time points having a first time interval and including velocity information indicating velocities of fluid on the plurality of grid points at each of the plurality of first time points; and
a processor coupled to the memory and configured to perform a procedure including:
calculating, based on the position information, a grid point moving velocity and a grid point moving acceleration of each of the plurality of grid points at each of the plurality of first time points;
calculating, based on the fluid information and by using an expression including the grid point moving velocity and the grid point moving acceleration as variables for correcting an error attributable to the accelerated motion of the plurality of grid points represented by the position information, time differential values of the velocities of the fluid on the plurality of grid points at each of the plurality of first time points,
calculating, based on the velocities and the time differential values of the velocities of the fluid on the plurality of grid points at each of the plurality of first time points, positions of a series of particles sequentially output from a particle generation source as the analysis time progresses at each of a plurality of second time points having a second time interval shorter than the first time interval, and
generating display information about a streakline indicating the series of the particles.

2. The streakline visualization apparatus according to claim 1 , wherein calculating the positions includes generating interpolation curves, each of which connects first positions indicating the velocities of the fluid on a corresponding one of the plurality of grid points at the plurality of first time points, each of which has a slope based on the time differential values of the velocities of the fluid indicated by the first positions respectively corresponding to the plurality of first time points, and each of which represents change in velocity of the fluid over time, and calculating, based on the individual interpolation curves of the plurality of grid points, the positions of the series of the particles at each of the plurality of second time points.

3. The streakline visualization apparatus according to claim 1 ,
wherein the memory further stores structure information indicating change of a shape of a structure in the analysis space over time, and
wherein, when calculating a second streakline at a second analysis time point, based on a first streakline at a first analysis time point, the procedure further includes setting a partial region including a discrete point at a first position on the first streakline in the analysis space as an analysis target region of the discrete point, calculating, based on the velocities of the fluid in the analysis target region, the velocities indicated by the fluid information, a second position indicating a destination of a particle on the discrete point at the second analysis time point, determining, based on information about the structure in the analysis target region, the information indicated by the structure information, a region occupied by the structure in the analysis target region at the second analysis time point, determining entrance or non-entrance of the second streakline into the occupied region, based on the first position and the second position, and generating display information about the second streakline passing through the second position, when determining that the second streakline does not enter the occupied region.

4. The streakline visualization apparatus according to claim 1 , wherein the procedure further includes displaying the streakline, based on the display information.

5. A streakline visualization method comprising:
calculating, by a processor, based on fluid information including position information indicating positions of a plurality of grid points that move with accelerated motion in an analysis space as analysis time of a fluid simulation progresses, at each of a plurality of first time points having a first time interval and including velocity information indicating velocities of fluid on the plurality of grid points at each of the plurality of first time points, a grid point moving velocity and a grid point moving acceleration of each of the plurality of grid points at each of the plurality of first time points;
calculating, by the processor, based on fluid information, by using an expression including the grid point moving velocity and the grid point moving acceleration as variables for correcting an error attributable to the accelerated motion of the plurality of grid points represented by the position information, time differential values of the velocities of the fluid on the plurality of grid points at each of the plurality of first time points;
calculating, by the processor, based on the velocities and the time differential values of the velocities of the fluid on the plurality of grid points at each of the plurality of first time points, positions of a series of particles sequentially output from a particle generation source as the analysis time progresses at each of a plurality of second time points having a second time interval shorter than the first time interval; and
generating display information about a streakline indicating the series of the particles.

6. The streakline visualization method according to claim 5 , wherein calculating the positions includes generating interpolation curves, each of which connects first positions indicating the velocities of the fluid on a corresponding one of the plurality of grid points at the plurality of first time points, each of which has a slope based on the time differential values of the velocities of the fluid indicated by the first positions respectively corresponding to the plurality of first time points, and each of which represents change in velocity of the fluid over time, and calculating, based on the individual interpolation curves of the plurality of grid points, the positions of the series of the particles at each of the plurality of second time points.

7. The streakline visualization method according to claim 5 , further comprising:
storing structure information indicating change of a shape of a structure in the analysis space over time, and
wherein, when calculating a second streakline at a second analysis time point, based on a first streakline at a first analysis time point, further including setting a partial region including a discrete point at a first position on the first streakline in the analysis space as an analysis target region of the discrete point, calculating, based on the velocities of the fluid in the analysis target region, the velocities indicated by the fluid information, a second position indicating a destination of a particle on the discrete point at the second analysis time point, determining, based on information about the structure in the analysis target region, the information indicated by the structure information, a region occupied by the structure in the analysis target region at the second analysis time point, determining entrance or non-entrance of the second streakline into the occupied region, based on the first position and the second position, and generating display information about the second streakline passing through the second position, when determining that the second streakline does not enter the occupied region.

8. A non-transitory computer-readable stora

Assignees

• Fujitsu Ltd
• Univ Tokyo

Inventors

• Kushibe Daisuke
• Watanabe Masahiro
• Hisada Toshiaki
• Sugiura Seiryo
• Washio Takumi
• Okada Jun-Ichi

Classifications

• G06F2119/06

  Power analysis or power optimisation · CPC title

• G06F2113/28

  Fuselage, exterior or interior · CPC title

• G06T2207/30104

  Vascular flow; Blood flow; Perfusion · CPC title

• A61B6/504

  for diagnosis of blood vessels, e.g. by angiography · CPC title

• G06F30/15

  Vehicle, aircraft or watercraft design · CPC title