Computational Fluid Dynamics

Computational fluid dynamics applied to solving 3D aerodynamic flows and heat transfer 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 wing anti-icing system is an example of a complex aerodynamic flow that prevents ice-formation on the external surface of the wing of the A380 and A350. Hot air is bled from the engine and delivered to the wing slat via a piccolo tube. There are many small holes in the piccolo tube that 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. The 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 which 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 wing anti-icing process requires the calculation of high speed compressible flow at the piccolo holes where the flow may be choked (Mach number of 1), impingement of the gas jets on to the inner surface of the skin and 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. MMI Engineering is capable of such calculations and has worked closely with Airbus to support the design of the wing anti-icing system.

Other complex fluid flows include fluid sloshing in fuel tanks, cabin ventilation, ice accretion and internal pipe flows.