Influence of turbulent jet ignition and variable valve lift technology on the performance of spark ignition engine

undergraduate thesis

• Title (croatian): Utjecaj primjene pretkomore i varijabilnog otvaranja ventila na značajke rada Ottovog motora
• Author: Luka Preksavec
• Mentor: Momir Sjerić (mentor)
• Granter: University of Zagreb; Faculty of Mechanical Engineering and Naval Architecture; Zagreb
• Defense date and country: 2023-03-01, Croatia
• Scientific / art field, discipline and subdiscipline: TECHNICAL SCIENCES; Mechanical Engineering; General Mechanical Engineering (Construction)

Abstract

Turbulent Jet Ignition and Variable Valve Lift are relatively new technologies for improving the performance of internal combustion engines. Over the last years they have been a topic for many scientific researches. In this paper, the claimed performance gains are tested using a commercial simulation software GT-PowerTM. The benefits of those technologies are compared against the base engine model, created and calibrated using the experimental data from the test bench. The TJI is evaluated by modifying the base engine model, where assumed benefits of using the system will be imposed. Firstly, brake torque and power are simulated and compared to the base model. Following that, the compression ratio of the engine is increased to further examine the usage of the prechamber combustion. The influence on the exhaust temperatures is also inspected and the found improvements are exploited by increasing the access air ratio. VVL is examined by modifying the base model intake and exhaust valve profiles for different steady state points. The potential improvements in brake torque and power are examined at wide-open throttle conditions and again compared to the base model. For part load conditions, the reducement of pumping losses with the increasement of expansion work is targeted.

Abstract (croatian)

Izgaranje u pretkomori i varijabilno podizanje ventila relativno su nove tehnologije za poboljšanje značajki motora s unutarnjim izgaranjem. Proteklih godina bile su predmet istraživanja mnogih znanstvenih radova. Pretpostavke o poboljšanju značajki rada motora biti će ispitane koristeći komercijalni programski paket za simulacije GT-PowerTM. Prednosti spomenutih tehnologija uspoređene su sa osnovnim simulacijskim modelom motora koji je izrađen i kalibriran prema podacima s ispitne stanice. Izgaranje u pretkomori ispitano je izmjenom početnog modela, gdje su pretpostavke o uporabi pretkomore određene parametrima. Najprije su ispitani i uspoređeni efektivni moment i snaga koji su dobiveni simulacijama početnog i izmjenjenog modela. Nakon toga, kompresijski omjer motora biti će uvećan kako bi se nadalje promatrali učinci korištenja pretkomore. Utjecaj na temperaturu ispušnih plinova također je promatran te su poboljšanja primjenjena povećanjem pretička zraka. Varijabilno podizanje ventila ispitano je izmjenom profila podizaja usisnog i ispušnog ventila za različite radne točke. Poboljšanje iznosa efektivnog momenta i snage ispitano je u uvjetima punog opterećenja te također uspoređeno s osnovnim modelom. Za uvjete djelomičnog opterećenja cilj je smanjenje gibitaka tijekom izmjene radnog medija te povećanje rada prilikom ekspanzije.

• Keywords: Spark Ignition Engine; Turbulent Jet Ignition; Prechamber Ignition; Variable Valve Lift; Engine simulations; GT-PowerTM
• Keywords (croatian): Ottov motor; izgaranje u predkomori; varijabilno podizanje ventila; simulacije motora; GT-Power TM
• Language: english
• URN:NBN: urn:nbn:hr:235:033636
• Study programme: Title: Mechanical Engineering; specializations in: Design, Process and Energy Engineering, Production Engineering, Engineering Modelling and Computer Simulation, Marine Engineering, Industrial Engineering and Management, Materials Engineering; Course: Design; 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: Embargoed access; Embargo expiration date: 2025-03-01
• Created on: 2023-02-23 11:01:42