Simulacija radnog ciklusa Ottovog motora s pretkomorom

undergraduate thesis

• Title (english): Cycle-simulation of pre-chamber spark ignition engine
• Author: Alen Miklik
• Mentor: Momir Sjerić (mentor)
• Granter: University of Zagreb; Faculty of Mechanical Engineering and Naval Architecture; Zagreb
• Defense date and country: 2018-02-28, Croatia
• Scientific / art field, discipline and subdiscipline: TECHNICAL SCIENCES; Mechanical Engineering

Abstract

Posljednjih godina ponovno se pojavio interes za tehnologijom koja omogućava izgaranje siromašne smjese kod motora s unutarnjim izgaranjem, prvenstveno zbog poboljšanja ekonomičnosti potrošnje goriva i smanjenja emisija dušikovih oksida koje te tehnologije omogućavaju. Izgaranje siromašne smjese nastaje kada gorivo izgara u suvišku zraka te takav način rada motora ima mnogo prednosti pred konvencionalnim motorima sa stehiometrijskim izgaranjem (λ=1). Izgaranje siromašne smjese kod konvencionalnih Ottovih motora ne može se postići standardnom svjećicom, već svjećicu zamjenjuje sklop pretkomore s brizgaljkom za direktno ubrizgavanje male količine ( 3% ) goriva i svjećicom za zapaljenje tog goriva. U cilindar gorivo ( 97% ) se ubrizgava preko brizgaljke za direktno ubrizgavanje goriva. Zbog načina paljenja smjese goriva i zraka u cilindru, ovakav sustav naziva se „Turbulent Jet Ignition-TJI“. U ovom radu prikazana je usporedba konvencionalnog Ottovog motora i Ottovog motora s pretkomorom. Računalne simulacije provedene su u programskom paketu AVL BOOST™ v2013.2. U oba slučaja primijenjeni su kvazi-dimenzijski modeli izgaranja koji su dostupni u programskom paketu. Tijekom simulacija sve geometrijske značajke motora ostale su nepromijenjene čime je osigurano izdvajanje utjecaja modela izgaranja na performanse motora. Na kraju su prikazani, uspoređeni i objašnjeni simulacijski rezultati.

Abstract (english)

In recent years there has been renewed interest in lean burn combustion technologies in internal combustion engines, primarily due to the improvement in fuel efficieny and reduction of nitrogen oxide (NOx) emissions that these technologies can provide. Lean burn occurs when fuel is burnt in excess air and running an engine in this manner has many advantages over conventional stoichiometric combustion (λ=1). Combustion of lean mixture in conventional spark ignition (SI) engines can not be achieved with standard spark plug, so the spark plug is replaced with prechamber assembly with a direct injector (DI) that provides a small amount ( 3%) of fuel and a spark plug to ignite that charge. The cylinder is fuelled ( 97%) through direct injector. Due to the ignition of the fuel and air mixture in cylinder, this system is also known as „Turbulent Jet Ignition-TJI“. In this thesis is presented comparison between conventional spark ignition engine and pre-chamber spark ignition engine. Computer simulations were conducted using the AVL BOOST™ v2013.2 software package. In both cases quasi-dimensional combustion models were used which are available in software package. During the simulations all geometrical features of the engine remained unchanged, which ensured separation of the impact of the combustion models on engine performance. At the end simulation results are presented, compared and explained.

• Keywords: Ottov motor; Ottov motor s pretkomorom; AVL BOOST; Fraktalni model izgaranja
• Keywords (english): SI Engine; Pre-chamber spark ignition engine; AVL BOOST; Fractal combustion model
• Language: croatian
• URN:NBN: urn:nbn:hr:235:697145
• Study programme: Title: Mechanical Engineering; Study programme type: university; Study level: undergraduate; Academic / professional title: sveučilišni/a prvostupnik/ prvostupnica (baccalaureus/baccalaurea) inženjer/inženjerka strojarstva (sveučilišni/a prvostupnik/ prvostupnica (baccalaureus/baccalaurea) inženjer/inženjerka strojarstva)
• Type of resource: Text
• File origin: Born digital
• Access conditions: Open access
• Created on: 2019-05-22 21:44:16