- The application simulates fluid dynamics using the Lattice-Boltzmann model and helps to visualize fluid flow with different lattice types, collision operators, and boundary conditions.
- Supported lattice types :-
- D2Q9: 2D lattice with 9 velocity directions, 100x100 grid.
- D3Q15: 3D lattice with 15 velocity directions, 50x50x50 grid.
- D3Q19: 3D lattice with 19 velocity directions, 50x50x50 grid.
- D3Q27: 3D lattice with 27 velocity directions, 50x50x50 grid.
- Each lattice defines velocity vectors (C) and weights (W) for particle distributions. The simulation computes fluid density (rho) and velocities (ux, uy, uz) at each grid point, stored in arrays.
- Functions performed by simulation loop :-
- Compute macroscopic quantities: Calculates density and velocities from the distribution functions (f).
- Collide: Updates particle distributions based on the chosen collision operator.
- Stream: Moves distributions along velocity directions.
- Apply boundary conditions: Enforces rules at the grid boundaries.
- Visualization: Updates the canvas with the current velocity field.
- Collision operators :-
- SRT (Single Relaxation Time): Uses a single relaxation parameter (omega = 1/0.6) for all moments, applied to all lattices.
- MRT (Multiple Relaxation Time): Uses multiple relaxation rates for different moments, implemented for D2Q9 only.
- TRT (Two Relaxation Time): Uses symmetric and antisymmetric relaxation times, for D2Q9 only.
- Entropic: Adjusts relaxation to maximize entropy, for D2Q9 only. For 3D lattices, non-SRT operators default to SRT.
- Boundary conditions :-
- Bounce-back: Reflects particles at walls, simulating no-slip conditions.
- Velocity: Sets a fixed velocity (0.1 in x-direction) at the left boundary (x=0), with bounce-back elsewhere.
- Pressure: Fixes density (1.0) at the right boundary (x=NX-1), with bounce-back elsewhere.
- Periodic: Wraps particles around opposite boundaries.
- Inlet/Outlet: Combines velocity at the left and pressure at the right, with bounce-back on top/bottom.
- Open: Copies distributions from neighboring cells, allowing free flow through boundaries.
- The simulation initializes with a uniform density (1.0) and zero velocity, except for specific boundary conditions (e.g., 0.1 x-velocity at x=0 for Velocity/Inlet/Outlet). An obstacle is placed to demonstrate flow interaction, visible in the visualization.
 |
 |
|---|---|
 |
 |
 |
 |
 |
 |