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Ground transportation industry contributes to about 14% of the global CO2 emissions. Therefore, any effort in reducing global CO2 needs to include the design of cleaner and more energy efficient vehicles. Their design needs to be optimized for the real-world conditions. Using wind tunnels that can only reproduce idealized conditions quite often does not translate into real-world on-road CO2 reduction and improved energy efficiency. Several recent studies found that very rarely can the real-world environment be represented by turbulence-free conditions simulated in wind tunnels. The real-world conditions consist of both transversal flow velocity component (causing an oncoming yaw flow) as well as large-scale turbulent fluctuations, with length scales of up to many times the size of a vehicle. The study presented in this paper shows how the realistic wind affects the aerodynamics of the vehicle.

For the automotive industry, acoustic comfort is of increasing importance. The market and customer expectation make the HVAC system noise quality a question to be addressed as early as possible in the vehicle development process. On one hand, the so-called traditional sources of annoyance such as engine, road-tires contact, exhaust systems and wind-noise have been significantly reduced for most traditional combustion engine vehicles. On the other hand, considered in the past as secondary noise sources, HVAC systems become the main sources for hybrid and electric and Stop-start vehicles. Previous studies have demonstrated the ability of a CFD/CAA approach based on the Lattice Boltzmann Method (LBM) to predict HVAC system noise including real and complex ducts, registers, mixing unit and blower geometries.

Aerodynamic performance assessment of automotive shapes is typically performed in wind tunnels. However, with the rapid progress in computer hardware technology and the maturity and accuracy of Computational Fluid Dynamics (CFD) software packages, evaluation of the production-level automotive shapes using a digital process has become a reality. As the time to market shrinks, automakers are adopting a digital design process for vehicle development. This has elevated the accuracy requirements on the flow simulation software, so that it can be used effectively in the production environment. Evaluation of aerodynamic performance covers prediction of the aerodynamic coefficients such as drag, lift, side force and also lift balance between the front and rear axle. Drag prediction accuracy is important for meeting fuel efficiency targets, prediction of front and rear lifts as well as side force and yawing moment are crucial for high speed handling.