Search Results

Automakers are seeking more efficient and green vehicles projects in terms of fuel consumption and CO2 emissions. Several factors are directly related to the performance and one of the most important is the aerodynamics. Cars with smooth geometries and transitions are expected to have a better aerodynamic behavior compared with the ones with rough geometries. Regardless the vehicle geometry changes, another way to improve the aerodynamics is by adding new parts, in order to improve the drag coefficient of the car. Most of the time, these parts are added but the functionality is not well defined. The main objective of this work is to identify, explain the way it should work and some applications of additional aeroparts. Those parts could be assembled in a vehicle in order to improve the drag coefficient, have a better fuel economy and lower emissions rate.

Environment concerns lead the automakers to invest resources and put research in engine downsize to reduce carbon emission. Turbo charge is a possibility due to its fuel consumption and emission reduction without compromise the performance. Nowadays, it is becoming common observe high performance small cars due to high torque and power available. In consequence, brake system need to dissipate more kinetic energy without adding mass or costs. Modern passenger cars require a high-speed brake system. To achieve proper brake system cooling, the rotor must be ventilated and designed to optimize the energy dissipated, which is generated by friction between pad and disk. Some approaches consider the rotor as a centrifugal air pump and the design rule is to improve the airflow inside the vanes. The approach considering a brake rotor similar to centrifugal air pump rotor may be considered as limited approach, once it simplifies the heat transfer phenomena inside chamber.

The brake system is of vital importance when engineering a new vehicle due to its implication with both safety and overall performance. One of the main questions that arise when designing the brake system, not only in terms of performance but also in efficiency and fuel economy is how to make a better brake rotor. When designing the brake rotor, thinking about mass reduction and design optimization is a desire not only for high-performance motorsport, but for daily user applications. The impact on the vehicle performance would lead to improved fuel economy and braking safety. In this work, we propose to exploit some characteristics that can optimize the rotor design to achieve better performance, compared to a baseline design proposed. Some constructive characteristics are kept constant such as the rotor diameter and thickness. The use of computational fluid dynamics (CFD) simulations is considered in this study as a benchmark to future physical prototypes experiments.

Autonomous vehicles, which are defined as capable of sensing environment and navigating without any human input, are the top trend of the automobilist industry in terms of technology. The computers responsible for the control are able to set the vehicle to optimum operation point. With the advent of Computational Fluid Dynamics -CFD software, it is possible to study drag reduction proposals when the vehicles drive at the velocity, which contributes to increase fuel economy. In this context, based on a sedan virtual drag model, several simulations cases were developed considering different vehicle arrays and changing the distance between each one. The study aims to demonstrate, using virtual simulations, the potential drag coefficient reduction when vehicles are moving in a constant speed and which configuration leads to better performance increment. Taking the isolated vehicle as the baseline value, all the vehicles in the different arrays were analyzed.

Vehicle fuel filling may not occur the fastest way, mainly due to the filler neck geometry and low fuel flow from the pump. When the fuel tank in empty, the previous interferences are increased, once the inner pressure increases, complicating even more the fuel filling activity. Another problem that occurs due to poor filler neck design is fuel pump nozzle shut off, once the fuel flow can’t overcome the tank inner pressure causing fuel to return, turning off the pump or even leakage. The recent advances in CFD Codes and computational power allowed multiphase simulations to be performed in production level by the industries worldwide. This paper takes advantage of these advances and proposes a methodology for fuel filling simulation using multiphase CFD simulation in order to evaluate a filler neck design, by measuring the total filling time.

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.