Systems Fluid Dynamics Library for Coarse-Grid-CFD-simulation with Modelica

The Systems Fluid Dynamics library carries out CFD-Simulations using Modelica language and provides standard interfaces to 1D-Modelica-models for a seamless connection. The fluid dynamics are purely modelled by using Modelica language.

The Systems Fluid Dynamics Library allows the modelling and simulation of gas flows (e.g. humid air) in three-dimensional spaces. At the boundaries of the grid model local boundary conditions may be defined, which can change transiently or wall and window models can be attached. The maximum resolution of the cubic grid depends on the capacity of the computer hardware and is typically limited to about 1.000 - 2.000 cells. Larger spaces may even be modelled through the definition of symmetry boundary conditions.

Benefits

• No need for complex co-simulation and other tools since CFD models are part of the Modelica model

• Reduced elapse time for iterative work through faster simulations

• Instant simulation success since convergence is automatically controlled by the solver

• Full Modelica flexibility since the model code is open and transparent, user modifications can be introduced and the tool has more options for symbolic transformation

Highlights

• Zones Package: Modelling mobile or stationary climate zones under different boundary conditions

• The zone models account for the following physical phenomena:

  • Solar Irradiation, internal thermal radiation and external shading

  • Heat transfer through walls and windows

  • Internal Heat loads

• Weather Package: Modelling of Climate Conditions

• The weather connector contains the following data:

  • Ambient temperature

  • Ground temperature

  • Ambient pressure

  • Ambient humidity

• Physical gas dynamics are a pure result of geometry and the Navier-Stokes-equations