Simulation & Analysis


Computational Fluid Dynamics (CFD)

The reduced initial expenditure makes CFD ideal for preliminary configuration studies. In conjunction with experimental data validation, CFD allows also detailed flow analysis in the design envelope which may not be entirely covered by wind tunnel testing. By using the synergies between numerical and experimental methods under one roof we will reduce your development time and solidify the engineering results.

In collaboration with RUAG Aviation’s subsidiary CFS Engineering, a wide range of applications are covered with numerical simulations; from very low speeds (HVAC) up to hypersonics (reentry), steady state calculations and time resolved, including dynamic fluid structure interaction (FSI).


There is no “silver bullet” in numerical flow simulation. To generate accurate results over the different aerodynamic regimes covered by our simulation capabilities, different solvers have to be used, each having its strengths and weaknesses.  This leads to a mix of structured and unstructured solvers, based on Navier Stokes as well as Lattice Boltzmann approaches:

  • NSMB (inhouse code developed by CFSE, RANS, structured)
  • OpenFOAM (open source, RANS, unstructured)
  • SU2 (open source, RANS, unstructured)
  • XFlow (commercial, LBM)

Low-speed External Flow Simulation

Typical low speed applications for CFD at RUAG cover trains, turbofan simulators, propeller aircraft, helicopter and all sorts of aircraft in high-lift-configuration (takeoff/landing). High lift configurations are often measured in the RUAG Wind Tunnel allowing direct comparison of CFD to experimental results.

Low-speed Internal Flow Simulation

A heavy focus in internal flow simulation at RUAG Aviation lies on the support for wind tunnel- and body-flying-facility designs. CFD is a valuable tool to optimize the airline for these types of installations.

Wind tunnel airline optimization


High-speed Flow Simulation

Transonic, supersonic and hypersonic speeds are covered with high speed CFD methods. The application ranges from business jets and fighter aircraft, over missile payload fairings, small-arms projectiles up to reentry vehicles.

Heat, Ventilation and Air-Conditioning

Passenger comfort plays an important role in today’s aircraft design. Heat, ventilation and air-conditioning systems are often optimized using numerical simulation, e.g. CFD for cabin flow. These simulations are quite complex, as natural and enforced  convection as well as radiation have to be taken into account. Additionally, the turbulent characteristics of these types of flow often require the use of large eddy simulation (LES).

Heat, Ventilation and Air-Conditioning Simulation


Flow Simulation

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