|Tipo di tesi||Tesi di dottorato di ricerca|
|Titolo||Analisi Termo-Fluidodinamiche di ICE per propulsori ibridi ad alte prestazioni ed efficienza termodinamica|
|Titolo in inglese||Thermo-Fluid Dynamic Analyses of ICE for Hybrid Powertrains with High Performance and Thermodynamic Efficiency|
|Settore scientifico disciplinare||ING-IND/08 - MACCHINE A FLUIDO|
|Corso di studi||INGEGNERIA INDUSTRIALE E DEL TERRITORIO|
|Data inizio appello||2019-09-25|
|Disponibilità||Embargo di 3 anni|
|Data di rilascio||2022-09-25|
Il powertrain ibrido in studio per l’attività di ricerca è quello dell’attuale Power Unit F1, come definito dal regolamento FIA. Dal 2014, i motori F1 hanno cambiato nome in “power unit” e sono diventati 1.6 litri V6 sovralimentati con turbocompressore e sistemi di recupero energia maggiorati. Possono arrivare fino a 15000rpm e la portata carburante è limitata. Sono iniezione diretta (nel cilindro), con pressione di alimentazione benzina limitata a 500bar. Nel 2014 i Team avevano solo cinque power unit/macchina/stagione ed ognuna doveva percorrere 4000km. Nel 2018 le power unit sono limitate a tre/macchina/stagione e quindi ognuna deve percorrere 7000km.
The hybrid powertrain in study for the research activity is the one of the current F1 racing power unit, as defined by FIA regulations. From 2014, F1 engines changed name in "power unit" and they are 1.6 litre V6 boosted with a turbocharger and greater energy recovery systems. They can run at up to 15,000rpm and the fuel flow is restricted. They have direct fuel injection into cylinders, with fuel pressure limited at 500 bars. In 2014 Teams have just five power units/car/season and each has to last 4000km. In 2018 the power units are limited to three/car/season and each has to last 7000km. In 2013 the engines were 2.4 litre V8s with fuel indirect injection. In 2013 engines produced around 750HP at up to 18,000rpm. 2013 teams had eight engines/season/car and engine units had to last 2000kms. The new rules had the intent to make the F1 more “road relevant” and transform the performance increase to an efficiency increase, thanks to the fuel flow limitation to 100kg/h and also max fuel in to the car being 100kg. So the efficiency really makes the main role for the performance increase. The intent of this research is to investigate the main thermo-fluid dynamic topics to deal for the design and concept of an high efficiency and performance internal combustion engine that is part of an hybrid powertrain. So the investigated topics are: intake system and trumpet length, cam profiles for different scenarios, in-cylinder motions and turbulence and systems to enhance combustion velocity and efficiency, study of piston crevices and finally also heat rejection and improvements for predicting it. The method, used to face the single topic, changes in dependency to the detail requested and the modelling necessity. So it can start from the simple theory, then cfd 1d, cfd 3D transient arriving to combustion simulation with predictions of knock tendency. When possible, the result of the analyses are compared to experimental results or investigations, in order to properly close the loop from the design and simulation phase to the final experiment. This is easier for topic like trumpets and cams, it is much less easier for example for the evaluation of the in-cylinder transient low-scale turbulence for which only in-direct, invasive and not clear measurements can be performed and so skipped. The results for every investigated topics are shown in the manuscript, but often the final choices are not made explicit for reasons of confidentiality. The scope is anyway to show and discuss the technical issue, go in the full detail and the leave to the reader the chance to choose the best options. The overall intent was to investigate and report (when possible) in the research document the different technical solutions investigated when designing a new concept of Ice dedicated to hybrid high performance and high efficiency powertrain, running in F1 from 2014.