Enrico Cardile, Ferdinando Cannizzo, Giovanni Lombardi, Marco Maganzi
2010
Cubit, Ferrari, Università di Pisa
Abstract
Un'analisi aerodinamica che consideri gli effetti di tutti i parametri potrebbe sembrare difficile. Nell'analisi tramite ottimizzazione numerica un codice aerodinamico è accoppiato ad una routine di ottimizzazione per gestire automaticamente i valori delle variabili di progetto, con l'obiettivo di minimizzare una funzione obiettivo assegnata. Questo approccio è estremamente flessibile ed in grado di rispondere ad esigenze multidisciplinari.
Il progetto ha dimostrato l'applicabilità delle procedure di ottimizzazione nel contesto del settore automobilistico, utilizzando un codice CFD per l'aerodinamica. L'integrazione dell'ottimizzazione aerodinamica in fase di progettazione permette ai progettisti di interagire velocemente con gli altri gruppi. Diventa possibile cercare soluzioni che garantiscano le prestazioni cercate, che non influenzino negativamente lo stile dell'auto, e che al contempo diano un elevato grado di efficienza e sicurezza.
Enrico Cardile, Ferdinando Cannizzo, Giovanni Lombardi, Marco Maganzi
2010
Cubit, Ferrari, Università di Pisa
Abstract
Il comfort termico in abitacolo rappresenta un aspetto sempre più rilevante nella progettazione automobilistica ad alte prestazioni, risultando dall'interazione complessa tra fenomeni termo-fluidodinamici e percezioni fisiologiche soggettive.
Viene presentata una procedura integrata per la valutazione del comfort termico basata su simulazioni CFD, finalizzata alla definizione di indici quantitativi rappresentativi delle condizioni ambientali interne al veicolo. L'approccio combina l'analisi del campo di velocità, temperatura, umidità e irraggiamento con modelli di bilancio termico del corpo umano, introducendo un indice globale di comfort ottenuto dalla ponderazione di contributi locali legati a equilibrio termico, raffiche, gradienti verticali e laterali di temperatura.
Le simulazioni includono flussi freddi e caldi, meccanismi di conduzione, convezione e irraggiamento solare, su geometrie realistiche di abitacolo. La procedura è validata mediante prove sperimentali in galleria climatica e test soggettivi, mostrando una buona correlazione tra risultati numerici e dati sperimentali.
David Nuri, Ferdinando Cannizzo, Giovanni Lombardi
2010
Cubit, Ferrari, Università di Pisa
Abstract
The rear diffuser represents an important tool to increase the vertical load of a high-performance car. In order to improve its effectiveness, a solution based on flow blowing is considered. Different geometrical scheme of the blowing were considered. To make a corrected comparison between the different solutions, an optimisation procedure were applied to each geometrical scheme. Coarse tetrahedral grids are used during the optimisation process, while a final verification with a very refined grid is presented to validate the results. More than 2500 different configurations are analysed, spending one month on a 16 nodes linux cluster. Final results show that important increase in the down-force, without drag penalization, can be obtained by using flow-blowing devices.
Authors: Giovanni Lombardi, Nuri David, Ferdinando Cannizzo, Enrico Cardile
Conference/Journal: 8th MIRA International Vehicle Aerodynamics Conference, Oxford (GB)
Enrico Cardile, Ferdinando Cannizzo, Giovanni Lombardi, Marco Maganzi
2008
Cubit, Ferrari, Università di Pisa
Abstract
In the initial phase of a car project, difficulties arise from the high number of parameters involved. A systematic aerodynamic analysis taking into account the effects of all these parameters appears to be difficult, given the complexity related to both aerodynamic load evaluation and the assessment of general requirements of the car. In the analysis through numerical optimization, an aerodynamic code is coupled in a loop with an optimization routine, to automatically manage the values of the design variables, with the aim of minimizing a given objective function. This approach is extremely flexible, and capable of meeting multi-disciplinary requirements. Therefore, in the past, it was developed an advanced, integrated design and development environment for optimizing car aerodynamics, under certain geometrical and physical constraints imposed by the designer. A potential flow code was used initially; obviously, the capabilities of this model are restricted. The important increases in both the CFD algorithms and computing capabilities, suggested the possibility to use RANS solver in the optimisation procedure. Therefore, an activity to insert in the procedure a CFD code (FLUENT) was carried out. The process is driven by the code ModeFrontier, and it can now be considered a standard tool in aerodynamic design. In this paper the general scheme of the procedure is described, and an example of the capability to improve the aerodynamic characteristics of a high performance car is presented. By using this approach, increases in the results are obtained both in the initial phase of the project, the definition of the car shape, and in the final phase, in order to optimize the details.
Authors: G. Lombardi, S. Vannucci, F. Cannizzo, E. Cardile
Conference/Journal: 7th MIRA International Vehicle Aerodynamics Conference, England
Ferdinando Cannizzo, Giovanni Lombardi, Giuseppe Petrotta, Luca Caldirola, Marco Maganzi
2007
Cubit, Ferrari, Università di Pisa
Abstract
This paper presents the comprehensive aerodynamic development process of the Ferrari FXX supercar. The development was essentially based on intensive CFD use combined with wind tunnel validation. The work covers the complete aerodynamic optimization of the vehicle including underbody flow management, rear diffuser design, and active aerodynamic devices.
The Ferrari FXX represented a significant step forward in road car aerodynamics, implementing racing-derived technologies for improved downforce and drag management. CFD results were verified in Ferrari's wind tunnel facilities with differences less than 5% on global aerodynamic coefficients. The project demonstrated how advanced simulation tools can accelerate the development of high-performance vehicles while maintaining accuracy comparable to physical testing.
Conference/Journal: 6th MIRA International Vehicles Aerodynamics Conference, Warwick, UK (2006)
Ferdinando Cannizzo, Giovanni Lombardi, Luca Caldirola, Marco Maganzi
2006
Cubit, Ferrari, Università di Pisa
Abstract
This paper presents the comprehensive aerodynamic development process of the Ferrari FXX supercar. The development was essentially based on intensive CFD use combined with wind tunnel validation. The work covers the complete aerodynamic optimization of the vehicle including underbody flow management, rear diffuser design, and active aerodynamic devices.
The Ferrari FXX represented a significant step forward in road car aerodynamics, implementing racing-derived technologies for improved downforce and drag management. CFD results were verified in Ferrari's wind tunnel facilities with differences less than 5% on global aerodynamic coefficients. The project demonstrated how advanced simulation tools can accelerate the development of high-performance vehicles while maintaining accuracy comparable to physical testing.
Conference/Journal: 6th MIRA International Vehicles Aerodynamics Conference, Warwick, UK (2006)
