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One of the key components in engine cooling system design in internal combustion vehicles is the radiator, which is responsible not only for regulating the engine coolant temperature but also for the required airflow crossing the grille openings. Considering different construction techniques and materials, the radiator design and its characteristics influence the overall vehicle performance. This work proposes a study on the influences of the radiator in the overall performance of a conceptual vehicle design, when considering different parameters. The main radiator characteristics evaluate in this study are the construction type, heat exchange thin number and tube number in different configuration arrays. Virtual cfd simulations are used to perform this study, where the drag influence in verified in three velocities: 40, 60 and 80 kph and compared with a baseline vehicle.

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.

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.

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.

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.

The advances in High Performance Computing-HPC and CPU's sizes and processing power, combined with new computational codes, which are capable of coupling different types of simulation, are the main contributors for the increasing number of the Multiphysics simulations inside the industry. Multiphysics are defined as simulations involving multiple physical models or multiple simultaneous physical phenomena. Among some examples, spray modeling is of great interest in several branches of the industry and, with the development on algorithms and codes, simulations presented reliable results, compared to experiments. This work aims to contribute to both Multiphysics and spray modelling by reproducing a rainstorm condition, focused on a vehicular application. This work objective is evaluate the possibility and feasibility to reproduce virtually rain storm condition on a highway checking water intrusion at Air Intake System - AIS and compare with physical test.

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.

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.

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.

Within the advances in Computer Fluid Dynamics algorithms and High Performance Computing, large clusters become available at low costs allowing virtual simulations that were not possible some years ago at reasonable costs and time. This work uses intensively this condition and applies these advances on brake system optimization. The methodology developed in the present work verifies the best angular position for caliper inside the wheel to reduce the rotor temperature during braking process such as downhill procedure. Thus, this method is applied to a mini-VAN vehicle, where the best position is found, based on two design parameters: rotor temperature and convection heat transfer coefficient. This study shows that the most suitable position for initial selection is the first one.

The theory related to the thermal comfort of a human being is described in this article. It is not technically and economically feasible to provide optimal thermal comfort to a human being. The air temperature inside the vehicles is inhomogeneous mainly due to the ventilation system and to solar heat flux. The thermal stratification of air that results in difference of heat flux at the human body may cause thermal discomfort. In this case, it is important to quantify the degree of discomfort, which can be represented by the Predicted Mean Vote and Predicted Percentage Dissatisfied indices. This study intends to determine the thermal comfort for a human being inside vehicular cabins considering just the ventilation system with the same ambient temperature. A cabin of a vehicle is virtually reproduced in FLUENT® and the methodology of thermal comfort, based on previous works from the literature, is developed in Matlab 2010a and applied in this simulation.

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.

A real-time monitoring method for brake temperature rise in long downhill varying velocity according to a pattern to evaluate the BET (Brake Equilibrium Temperature) is expensive in time and money. The solution proposed here take advantage of recent advances in CFD Codes and computational power that allowed big models being run on clusters of production level by the industries worldwide. This paper takes advantage of these advances and proposes a methodology for Brake cooling simulation at downhill following a previously downhill map of time x velocity x pedal pressure. The methodology proposed presented 95% correlation with physical test and now is possible, in virtual word, to evaluate the entire downhill procedure for a new vehicle design before any physical prototype is available.

Aerodynamics plays a key role in nowadays vehicle development, aiming efficiency on fuel consumption, which 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 Auto Project to be implemented in Brazil on 2017. In order to meet requirements in terms of performance, especially on aerodynamics, automakers are focusing on aero-efficient exterior designs and also adding deflectors, covers, active spoilers and several other features to meet the drag coefficient. Usually, the aerodynamics properties of a vehicle are measured in both CFD simulations and wind tunnels, which provide controlled conditions for the test that could be easily reproduced. During the real operations conditions, external factors can affect the flow over the vehicle such as cross wind in open highways.

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.

CFD is becoming very popular among the industries and the use of multiphase simulations is also increasing with more powerful CPUs and reliable CFD codes. The scope of this work is to present a mud deposition simulation methodology using CFD multiphase analysis at the CRFM of an automobile, in order to prevent low performance on the condenser or on the radiator and compromise the heat exchange performance. Mud reaches the front end of the car and results show the mud path and mud deposition on the CRFM and the blocked area.