3D CAD Fluid Flow Simulation With Pressure-Gradient Body Force

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Solution Overview

Problem

Existing fluid flow simulations using compressible flow solvers introduce artificial compressibility effects when Mach numbers are artificially increased to reduce computational cost, leading to decreased accuracy and increased computational resources.

Innovation Solution

A data processing system applies a conformal body force to decouple pressure and density terms by performing a preparatory simulation to determine a conformal body force based on a pressure gradient, which is then used in a main simulation to drive the fluid flow, reducing artificial compressibility effects.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Loss of time

If the Mach number is artificially increased to reduce the number of time steps, then computational cost and time are reduced, but artificial compressibility effects are introduced decreasing simulation accuracy

Engineering Contradiction:
Improvesimulation timeVSAvoidsimulation accuracy
Core Design Contradiction:
Loss of timeVSMeasurement precision

Solution Approach 1:

A preparatory simulation is performed first to determine the pressure gradient field. This preliminary computation of the pressure gradient is then reused in the main simulation to drive the fluid flow, eliminating the need to solve pressure equations during the main simulation and allowing use of higher Mach numbers without compressibility errors

Inventive Principle:
Principle #10Preliminary action

Solution Approach 2:

The pressure gradient field acts as an intermediary that decouples the pressure and density terms. By using the pre-computed pressure gradient as a body force source term, the simulation avoids solving the pressure equation that would otherwise couple density and pressure, thereby eliminating artificial compressibility effects

Inventive Principle:
Principle #24Intermediary (Mediator)

2Productivity

If the Mach number is artificially increased to decrease the number of time steps, then computational resources are reduced, but compressibility effects are introduced affecting incompressible fluid flow accuracy

Engineering Contradiction:
Improvecomputational efficiencyVSAvoidsimulation reliability
Core Design Contradiction:
ProductivityVSReliability

Solution Approach 1:

The pressure gradient is computed in advance during a preparatory simulation phase. This pre-computed gradient is then used as a fixed body force in the main simulation, allowing the use of larger time steps and higher Mach numbers without compromising the accuracy of incompressible flow results

Inventive Principle:
Principle #10Preliminary action

Solution Approach 2:

The simulation approach changes the governing parameters by using a pre-determined pressure gradient field instead of solving the pressure equation dynamically. This parameter substitution allows higher Mach numbers to be used while maintaining accuracy for incompressible flows

Inventive Principle:
Principle #35Parameter changes

Data Source

PatentEP4668155A1Reducing artificial compressibility in digital internal fluid flow simulations
Publication Date: 2025.12.24 DASSAULT SYSTEMS AMERICAS CORP
  • EP4668155A1 patent drawingFigure 1
  • EP4668155A1 patent drawingFigure 2A~2B
  • EP4668155A1 patent drawingFigure 3~4

AI summary

Systems and methods for digitally simulating a fluid flow in a three-dimensional computer-aided design (CAD) model of a simulation space include receiving a digital representation of a simulation space based on a digital three-dimensional CAD model. The digital representation includes a plurality of voxels. A first fluid flow is digitally simulated by applying a driving force to the plurality of voxels in the digital representation of the simulation space to generate a pressure field. A volumetric body force is determined to apply to the plurality of voxels based on a pressure gradient of the pressure field. A second fluid flow is digitally simulated by applying the volumetric body force to the plurality of voxels.