The Open Source CFD code dolfyn is an initiative in Noord-Brabant, a Dutch province in the south of the Netherlands, particularly in the region around Eindhoven. The goal of dolfyn is to promote, introduce and teach the use of modern numerical simulation techniques in general and the use of Computational Fluid Dynamics (CFD) in particular.

Heat and Flow

Heat and mass transfer, transport phenomena, and fluid dynamics play an important role in various products, machines and in our daily life.

Examples are:

  • Automotive Industry

    • Drag resistance of vehicles
    • Fouling
    • Passenger comfort
  • Heating and Cooling

    • Heat exchangers
    • Cooling of electronics
  • Flows in Pipes and Tubes

    • Industrial installations
    • Airconditioning
  • Wind in the Built Environment

    • Wind forces
    • Wind nuisance for pedestrians and cyclists


Dolfyn is aimed towards the fulfilment of the above mentioned basic needs and to supply all necessary ingredients.

More specific:

  • Easy to use CFD software for numerical simulations and visualisation of results.
  • Training and courses in fluid dynamics in general, and Computational Fluid Dynamics in particular, accompanied by suitable training material.
  • A network of students, users and specialists.

Some uses and users

Dolfyn is used as the underlying CFD engine in other codes:

  • One of the first codes to use dolfyn was Comflow. Comflow is an inexpensive 2D CFD code that has been developed since 1993 by a group of Dutch companies. Comflow was based on a very simple structured hex grid solver (Comsolv) before dolfyn was adapted in 2006.
  • The CFD engine in Maelstrom for real time data center temperature modeling for energy efficient data centers (a project by the University of Michigan).

It is also used for benchmarking:

  • The National Institute of Standards and Technology (NIST) used dolfyn for their FiPy project (the fluid flow example of a rudimentary Stokes solver).

and at universities


Enjoy the dolfyn site!

Quick Download

Above file is the latest official version. For older versions and more information visit the Downloads page.

Below are the latest examples. To view them all go to the Examples page.