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Politecnico di Torino
Anno Accademico 2012/13
01OFGLO
Car body design and aerodynamics
Corso di Laurea Magistrale in Ingegneria Dell'Autoveicolo (Automotive Engineering) - Torino
Docente Qualifica Settore Lez Es Lab Tut Anni incarico
Tonoli Andrea ORARIO RICEVIMENTO O2 IIND-03/A 66 34 0 0 15
SSD CFU Attivita' formative Ambiti disciplinari
ING-IND/14 10 B - Caratterizzanti Ingegneria meccanica
Presentazione
This module provides information regarding the design of the vehicle bodywork keeping in mind the various functions involved. the areas covered include ergonomics, climatic, acoustical and vibrational comfort, layout of the structure and safety.
It provides the concepts of aerodynamic behaviour in motor vehicles and its methods of analysis and numerical and experimental optimization, in harmony with the style and architectural needs. On the course, the influence of the aerodynamics with regards to comfort and the cooling systems will also be affronted.
Risultati di apprendimento attesi
Students should acquire skills in the area of bodywork design with particular reference to bodywork functions.
Metodology of vehicle aerodynamics, experimental techniques in wind tunnel and CFD (Computational Fluid-Dynamics) instruments of calculation used for the motor vehicle.
Prerequisiti / Conoscenze pregresse
Knowledge of fluid mechanics and the numeric calculus methods.
Programma
1 - Introduction
Prerequistes and functions of the motor vehicle from the bodywork point of view.
2 – Ergonomics and use of space
Principles of posture
Principles of human vision
Principles of movement
Percentiles and manikins used
Seating position
Livability
Accessibility
External and Internal visibility
Manoeuvrability and command access
Loading and unloading of goods
3 – Climatic comfort
Physiological principles of climatic comfort
Criteria for measuring flows
4 – Structural integrity
Bodywork design: construction details for hatchbacks and saloons, spiders, MPVs, commercial vehicles, lorry cabs.
Examination of influencing external loads; evaluation of internal loads; evaluation of external loads
Simplified model for the functional analysis of the car structure when subject to internal and external loads
Torsional behaviour
Flexural behaviour
5 – Acoustical and vibrational behaviour
Principles of the physiology of the human ear and noise quality
Vibration and noise sources
Dynamic behaviour of the bodywork and modal analysis
Engine suspension
Squeaks and rattles
Noise diffusion via air
Acoustic insulation
6 - Safety
Preventative, active and passive safety
Passive safety: reference to international standards
Crashes of small intensity
Crash tests
External illumination and signal devices ; reference to international standards
Prerequisites and evaluation of devices.
1. Reference to fluid-dynamics
Equations of movement for uncompressible and compressible fluids.
Limited laminar and turbulent layers
Concepts of resistance from friction and pressure.
Criteria for similarities
2. Aerodynamic resistance
Resistance to movement.
Effect on consumption and performance.
Flow structure around squat bodies
Contributions to the aerodynamic resistance and parameters of synthesis.
Influence on the aerodynamic performance of significant variations of shape.
Resistance in commercial and industrial vehicles.
3. Aerodynamic problems inherent to the dynamic behaviour, to the comfort and to the cooling
Aerodynamic noise.
Stability with lateral wind.
Lift decrease for high performance vehicles.
Engine cooling
Brake cooling.
Aerodynamic forces on the bodywork.
Soiling and dispersion of exhaust fumes.
4. Experimental aerodynamics
Automobile wind tunnels.
Tests on scale models.
Measurement of the strength and aerodynamic torque.
Techniqu es for measuring the fluid-dynamic size (pressure, speed, heat cables, LDV, PIV).
Analysis of aerodynamic noise.
Analysis of air flows under the bonnet
Road tests.
5. Computational aerodynamics
Numeric methods for equations of fluid motion.
Calculations grids and their creations based on CAD geometry.
Examples of turbulence.
Surrounding conditions.
Elaborations and visualization of the results.
6. Aerodynamic development of vehicles
Simultaneous development of aerodynamic forms, style and planning of the vehicle.
Improvement of the form and interaction with the style.
Varying evaluations of the shaft and lateral winds.
Optimization of the additions.
Reduction of the bodywork resistance.
Organizzazione dell'insegnamento
Students carry out practical work on the following:
Ergonomical evaluation of a vehicle; postural comfort; external visibility
Evaluation of the torsional stiffness of a bodywork via a simplified model and identification of the possible improvements.
Applicable examples of the calculus codes CFD.
Instrumentation of measure for calibration.
Measuring of pressure field on scale models.
Testi richiesti o raccomandati: letture, dispense, altro materiale didattico
Folders of notes are available for the students.
Texts for further information :
J. Fenton, "Handbook of Vehicle Design Analysis", SAE, 1999
W. Karwowsky, "Automotive Ergonomics", Taylor & Francis, 1993
J. Happian-Smith e altri, "An Introduction to Modern Vehicle Design", SAE, 2002
T. Gillespie, "Fundamentals of Vehicle Dynamics", SAE, 1999
Hucho W. H. – Aerodynamics of Road Vehicles
Pope-Rae – Low Speed Wind Tunnel Testing
Criteri, regole e procedure per l'esame
There is a written test at the end of the didactic period, a further wirtten examination at the end of the module and assessment of practical work completed during the course.
Orario delle lezioni
Statistiche superamento esami

Programma definitivo per l'A.A.2012/13
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