2D Flow Field Example

Location: examples/webapp/flow2d/

Simulates 2D lid-driven cavity flow and visualizes the velocity field as colored arrows.

Inputs

  • Grid Size – N x N grid resolution

  • Kinematic Viscosity – fluid viscosity (affects Reynolds number)

  • Lid Velocity – speed of the moving lid

Key concepts

Vector field output (3-component per point):

# Interleaved vx, vy, vz values
vec_text = "\n".join(
    f"{vx[k]} {vy[k]} 0.0" for k in range(npoints)
)
rx['output.field(velocity).component.mesh'] = 'output.mesh(grid)'
rx['output.field(velocity).component.values'] = vec_text
rx['output.field(velocity).component.extents'] = '3'

  • extents=3 tells the renderer this is a 3-component vector field.

  • The webapp renders vector fields as colored arrows.

  • Use about.group to overlay vector and scalar fields on the same view.

Running

rappture2web examples/webapp/flow2d/