Drive airflow from a fan curve

Use fan_inlet when a fan sits on the exterior domain and its static-pressure curve should determine the operating flow rate.

Prepare the fan curve

Use the manufacturer’s static pressure data, not total pressure. Express flow_rates in m³/s and static_pressures in Pa. The arrays must have equal lengths, contain at least two samples, and use unique non-negative flow rates.

Provide the complete relevant curve, including the zero-flow and zero-pressure ends when available. Vanellus sorts samples by flow rate and clamps operation to the supplied range; an operating point at an endpoint often means the curve needs extending or the system setup is inconsistent.

Set the exterior fan opening

Add the condition to the fan opening:

{
  "boundary": {
    "circle": {
      "side": "x_min",
      "center": [0.05, 0.05],
      "radius": 0.02,
      "mesh_resolution": 12
    }
  },
  "condition": {
    "fan_inlet": {
      "ambient_pressure": 0.0,
      "flow_rates": [0.0, 0.02, 0.04],
      "static_pressures": [120.0, 70.0, 0.0],
      "temperature": 20.0
    }
  }
}

Complete and stabilize the flow path

Provide a pressure outlet elsewhere in the domain so the fan has a complete flow path. If the fan pressure oscillates, reduce its relaxation_factor.

See also

• Add an internal fan applies a fan curve when the fan is entirely inside the fluid domain.
• Fan and linked-fan boundaries explains how the operating point is coupled into the solver.
• API reference lists fields and limits.