Search Results

Cargo trucks are one of the most important and flexible ways of moving cargo within inlands. In some countries, such as Brazil, the economy relies on them to transport all kinds of products, from field and factory to consumer. In order to reduce freight prices, beside route optimization, truck manufactures started to focus on the aerodynamics development of those vehicles, in order to improve the efficiency, reducing fuel consumption and emissions. Although the truck aerodynamics development is important, most vehicles are not manufactured or don’t consider the truck trailer, which plays a key role in the full aerodynamics performance of the truck, once it might increase the front area and also change the overall aero performance.

Thanks to advances in Computational Fluid Dynamics - CFD codes, i.e. algorithms and turbulence models, complex CFD vehicles simulations are increasing not only in academia, but also in the industry itself. The aim of the simulations is to verify the aerodynamic behavior of a car at early stages of the project, when no prototype is available, and to reduce the total aerodynamic development time of a new vehicle. The turbulence model considered in the CFD simulation should be able to capture the main flow effects around the vehicle. Most importantly, the predicted total drag value of the vehicle has to be comparable to the values obtained in wind tunnel tests. The main focus of the presented work is a comparison of wind tunnel and CFD results of the same small production hatchback vehicle.

Nowadays, one of the most important roles in vehicle development is the aerodynamic, which aims efficiency on fuel consumption and leads to a green technology. Several initiatives around the world are regulating emissions and efficiency of vehicles such as EURO for European Marketing and the INOVAR Project to be implemented in Brazil on 2017. Thus, this study intend to perform an optimization to minimize the drag force of a hatchback vehicle. The main goal of this work is demonstrate the potential of optimization techniques to provide an aerodynamic shape improvement for the driver side outside rear view mirror of a hatchback vehicle. The optimization solver used in this work is the Adjoint Solver, which makes shape sensitivity analysis and mesh/volume morphing. The study was conducted using CFD simulations to reduce the drag force of current production hatchback vehicle previously validated and correlated in wind tunnel test.

Moving ground simulation plays an important role on aerodynamic studies of road vehicles, in order to reproduce the real movement condition. Due to cost of implementing a moving ground, many wind tunnels employ static ground simulation with boundary layer control. The work here presented aims to study using Computational Fluid Dynamics - CFD simulations the effect of using moving ground simulations with rotating wheels against a baseline configuration using both static ground and wheels over a small pick-up truck. The study aims to determine the influence of using different flow velocities on the drag coefficient measured over this vehicle using both ground configuration. For the cases here presented we performed steady state Reynolds-Averaged Navier-Stokes - RANS numerical simulations, following similar setup as the industry best practices and using the same mesh.

The automakers pursue for fuel economy is increasing year after year, both by the demands of society and by political pressures, leading companies to develop new solutions and technologies in order to increase the energy efficiency of vehicles. With the advent of CFD software, it is possible to study drag reduction proposals, which contributes to increase fuel economy. In this context, based on a small sedan vehicle virtual drag model, correlated with the wind tunnel test, a conceptual wheel was assembled proposing 3 blade angles in order to verify the influence on the drag coefficient. Considering the drag contribution of wheel in total vehicle drag is around 25%, this work aims to show the sensitivity in the drag coefficient by changing the wheel rim of a small sedan vehicle.