CFD-Aided Design of an Airbox for Race Cars 2002-01-2167

The design of a “high-performance” airbox for a naturally aspirated internal combustion engine (ICE) of a car racing in prototype sport competitions is described.

A computational approach to achieve optimum airbox geometry in terms of fluid dynamical losses reduction and engine volumetric efficiency improvement is proposed.

Experiments on race track have been carried out to test the car performances improvement.

The numerical calculations have been done using a 3D numerical code. The code solves finite-difference approximation of the fluid dynamic governing equations (continuity, momentum and energy balance). The solution has been performed numerically by an integration both in space and time by means of the Arbitrarian Lagrangian Eulerian (ALE) technique.

The numerical simulations have been carried out imposing steady and unsteady boundary conditions. The first ones allow to define the fluid dynamic losses and the airbox fluid dynamic behavior in order to identify an “optimum” design; the last ones, defined by means of a 1D code which takes into account the whole engine fluid dynamic scheme, contribute to describe the airbox behavior under more realistic operating conditions.

The developed procedure has allowed to define the airbox geometry to be tested on race track. Tests show that there is a great improvement of car performances in comparison to the ones obtained with the unmodified airbox which originally equipped the car.