Determination of the static head influence at time variable acceleration in 3D space is required

Static head influence on pressure distribution is accounted for in the component models for pipes and tanks. This requires the knowledge of their exact positions in 3D-space. The positions in the fuel system are set in all dynamic volume components and received by the flowmodels. Connectors with a black box (get position) can only be connected to connectors with a grey box (set position). If dynamic volumes are added or removed via corresponding flags the connection line has to be removed and redrawn, since the connectors change their names.

General fuel system model assumptions

  • All pressures in the connectors are assumed to be total pressures, the sum of the static pressure p and the dynamic pressure rho/2*v^2. Since the pressure at the connector is equal to that in the attached dynamic volume, the total pressure instead of the correct static pressure is used there to compute the thermodynamic medium properties. The deviations are assumed to be negligible.
  • The air medium used in the fuel system is assumed to be pure dry air.
  • Static head depending on variable acceleration in 3D space is only accounted for in the components tank and pipe.
  • Liquid fuel and air always flow in the same flow direction with the same velocity
  • Chosen pressure drop correlations are assumed to be applicable for both, liquid fuel and air
  • Position information is always passed from a volume component to a flowmodel component (e.g. a tank port to a pipe end) and needs to be specified as a parameter in the tank component.