Optimizacija usisnog i ispušnog sustava motora bolida Formula student

master's thesis

• Title (english): Optimization of the intake and exhaust system of Formula student car engine
• Author: Dominik Grubić
• Mentor: Darko Kozarac (mentor)
• Granter: University of Zagreb; Faculty of Mechanical Engineering and Naval Architecture; Zagreb
• Defense date and country: 2018-07-11, Croatia
• Scientific / art field, discipline and subdiscipline: TECHNICAL SCIENCES; Mechanical Engineering

Abstract

U okviru ovog rada izvršena je optimizacija usisnog i ispušnog sustava motora bolida Formula Student. Na početku rada prvo je bilo potrebno proučiti pravilnik o natjecanju kako se ne bi ponudilo rješenje, koje će se pokazati kao najbolje, ali istovremeno suprotstavljati odredbama pravilnika. Optimizacijom usisa nastoje se ostvariti poboljšane performanse motora. U startu je odmah odbačena ideja da se koristi turbopunjač, pošto je riječ o jednocilindričnom motoru, a u obzir treba uzeti i samu težinu turbopunjača kao i potrebu za ugradnjom hladnjaka stlačenog zraka, koji također svojstveno pridonosi većoj ukupnoj masi bolida. Stoga je odlučeno da se poboljšanje performansi motora nastoji ostvariti dinamičkim nabijanjem, koje kao takvo može pridonijeti povećanju performansi uz neznatno povećanje mase. Shodno tome, razvijena je ideja varijabilnog usisa, pomoću kojeg je moguće postići optimalne performanse na cijelom području brzine vrtnje motora. Analiziran je slučaj s dvije i tri duljine cijevi u sklopu varijabilnog usisa te je prikazana njihova usporedba. Također, u sklopu optimizacije usisa ispitan je utjecaj smanjenja volumena usisnog plenuma. Smanjenje volumena plenuma prvo je analizirano pomoću stacionarnih simulacija u kojima se pratio porast, odnosno pad momenta, a potom i pomoću tranzijentnih simulacija pomoću kojih je moguće usporediti brzinu odziva motora. Optimizacija ispušnog sustava motora svodi se na jedan osnovni zadatak, a to je konstruirati takav ispušni sustav, s kojim će bolid zadovoljavati dopuštenu razinu buke propisanu pravilnikom. Optimizacija ispuha se stoga zapravo svodi na traženje kompromisa između dobrih performansi motora i dozvoljene razine buke. U konačnici, razvijen je takav ispušni sustav koji zadovoljava dopuštenu razinu buke i s kojim se ostvaruju zadovoljavajuće performanse motora. Optimizacija usisnog i ispušnog sustava provedena je korištenjem numeričkih simulacija u sklopu programskog paketa AVL BoostTM.

Abstract (english)

In this thesis, optimization of the intake and exhaust system of Formula Student car engine was performed. At the beginning of the thesis, first it was necessary to review the competition rules in order not to present the solution, which would appear to be the optimal solution but at the same time it opposes the regulations of the rules. The purpose of the intake system optimization is to increase engine performance. The idea of using a turbocharger was immediately rejected, as it is a single-cylinder engine and it should take into account the weight of the turbocharger as well as the need for intercooler installation, which also contributes to the bigger mass of the vehicle. Therefore it was decided to increase engine performance with dynamic turbocharging, which can contribute to increased performance with a slight increase in a vehicle mass. Accordingly, the idea of variable intake manifold has been developed in order to achieve optimal engine performance throughout the engine speed range. The variable intake manifold with two and three pipe lengths were analyzed and compared. Also, as part of intake optimization, the influence of plenum volume reduction was examined. The reduction in the plenum volume was first analyzed by stationary simulations in which a momentum rise and droop were observed, followed by transient simulations in order to compare engine response. The foreground task of exhaust system optimization is to design such an exhaust system which will gratify noise level prescribed by the book of regulations. Therefore the exhaust system optimization is reduced to seeking compromise between high engine performance and permitted noise level. In the end, an exhaust system that meets the permitted noise level and achieves satisfactory engine performance is developed. Optimization of the intake and exhaust system was carried out using numerical simulations within the AVL BoostTM.

• Keywords: optimizacija; usis; ispuh; rezonancija; simulacija; performanse; razina buke; odziv motora; Formula Student
• Keywords (english): optimization; intake; exhaust; resonance; simulation; performance; noise level; engine response; Formula Student
• Language: croatian
• URN:NBN: urn:nbn:hr:235:232983
• Study programme: Title: Mechanical Engineering; Study programme type: university; Study level: graduate; Academic / professional title: magistar/magistra inženjer/inženjerka strojarstva (magistar/magistra inženjer/inženjerka strojarstva)
• Type of resource: Text
• File origin: Born digital
• Access conditions: Open access
• Created on: 2019-05-22 22:36:48