Computational Fluid Dynamics

Computational fluid dynamics quantifies the performance and design of complex flows in the aerospace industry.

MMI Engineering provides technical consulting services to the aerospace industry. Calculation of 3D aerodynamic and fluid dynamic flows and heat transfer using computational fluid dynamics assists in quantifying the performance and design of complex flow systems.

The Airbus A380 and A350 anti-icing system is an example of a complex aerodynamic flow, which prevents ice-formation on the external surface of the wings. Hot air is bled from the engine and delivered to each wing slat via a piccolo tube. There are many small holes in the piccolo tube, which allow jets of hot air to impinge on and warm the inner surface of the skin, therefore preventing ice formation on the external surface. As the structural components of the slat warm, stresses occur due to the expansion of the components, however, such stresses reduce when the anti-icing system is not required (e.g. when the aircraft is on the ground). This cyclic stressing is referred to as ‘thermal fatigue’ and limits the life of the wing slat. In order to assess thermal fatigue, the structural temperatures are calculated using CFD and are exported for FEA fatigue analysis. The calculation of the anti-icing process requires the analysis of high speed compressible flow at the piccolo holes, where the flow may be choked (Mach number of 1), and where the gas jets impinge onto the inner surface of the skin. Heat transfer from the gas to the solid, as well as radiative heat transfer from the piccolo tube to the structural components of the wing slat, also needs to be calculated.

MMI Engineering is capable of such calculations and has worked closely with Airbus to support the design of their anti-icing system. Other examples of complex fluid flows we can assist with include:

  • Fluid sloshing in fuel tanks
  • Cabin ventilation
  • Ice accretion
  • Internal pipe flows