Numerička simulacija dinamike klipa i klipnih prstena

master's thesis

• Title (english): Simulation of piston and piston ring dymanics
• Author: Ljudevit Putarek
• Mentor: Darko Kozarac (mentor)
• Granter: University of Zagreb; Faculty of Mechanical Engineering and Naval Architecture; Zagreb
• Defense date and country: 2019-05-17, Croatia
• Scientific / art field, discipline and subdiscipline: TECHNICAL SCIENCES; Mechanical Engineering

Abstract

Trenje izazvano radom klipnog mehanizama doprinosi 40% do 50% ukupnom trenju motora s unutarnjim izgaranjem. Proizvođači automobila traže učinkovite metode u smanjenju trenja bez nedostataka u izdržljivosti, buci i vibracijama. S obzirom na to, efikasno ispitivanje parametara i optimizacije simulacijskih modela dobiva sve više na važnosti. Cilj rada istražiti je razlike u rezultatima između simulacije i mjerenja provedenih na motoru AVL FRISC. AVL FRISC je jednocilindarski motor s unutarnjim izgaranjem konstruiran za proučavanje rezultata dinamike klipa i klipnih prstena s naglaskom na rezultate sile trenja, bočne sile klipa, srednjeg tlaka trenja, potrošnje ulja klipnog mehanizma i prestrujavanja zraka u donji dio kućišta motora (blow-by). Simulacijski modeli izrađeni su u programima AVL EXCITE™ Piston&Ring i AVL EXCITE™ Power Unit. U programu AVL EXCITE™ Piston&Ring izrađena su dva modela koji se razlikuju s obzirom na korišteni paket klipnih prstena, osnovni paket klipnih prstena i paket klipnih prstena sa smanjenim trenjem. Također, izrađeni su modeli koji se razlikuju u pristupu rješavanja simulacijskog modela: pojednostavljeni pristup ili 2D te napredniji pristup ili 3D. Rezultati potrošnje ulja klipnog mehanizma, prestujavanja zraka, dinamike klipnih prstena i gubitaka trenja klipnih prstena dobiveni su simulacijom u programu AVL EXCITE™ Piston&Ring. Proučavanje ukupnih gubitaka tlaka trenja klipnog mehanizma, sile trenja i bočne sile na klip provedeno je u programu AVL EXCITE™ Power Unit s osnovnim paketom klipnih prstena i paketom klipnih prstena sa smanjenim trenjem. Simulacijski modeli izrađeni su na pojednostavljen i napredan način. Pojednostavljeni model koristi REVO spoj, dok napredan model koristi EHD spoj. Prikazani su rezultati dinamike klipa, gubitci trenja klipa, sile trenja i bočne sile na klipu. Dostupna su mjerenja potrošnje ulja, prestrujavanja zraka, sile trenja, bočne sile na klipu i srednjeg tlaka trenja, kao i njihova usporedba sa simulacijskim rezultatima. Na kraju je prikazan utjecaj parametara na usklađivanje simulacijskog modela i mjerenja.

Abstract (english)

Piston group is the main contributor to friction with an amount of 40%-50% of the total IC engine friction. The market is looking for efficient friction reduction methods without drawbacks in durability and NVH. In light of this, efficient parameter studies and optimization processes in multibody dynamics simulation are becoming increasingly important and must be setup. The aim of this thesis is to investigate the differences in the results of simulation and measurement on the AVL FRISC engine. The AVL FRISC (FRIction Single Cylinder) engine is a research IC engine designed for the investigation of piston and piston ring dynamics in view of measuring friction force side force, friction mean effective pressure (FMEP), lube oil consumption (LOC) and blow-by values. Simulation models are built in the AVL EXCITE™ Piston&Ring and AVL EXCITE™ Power Unit software’s. In EXCITE™ Piston&Ring, models with two different piston ring packages (basic and low friction package) are created for different simulation solvers: simplified (2D) and advanced (3D) solver. The differences between the basic and low friction ring package is in the tangential force. The results of LOC, blow-by, piston ring dynamics and piston ring friction losses are given by the AVL EXCITE™ Piston&Ring software. To investigate the total FMEP values of piston group, friction force and side force, AVL EXCITE™ Power Unit models are created for a basic and low friction package. Simulation models are also created with a simplified and advanced approach. Revolute Joints (REVO) are used in the simplified approach, whereas Elasto-Hydrodynamic journal sliding bearing (EHD2) is used in the advanced approach. The results of piston dynamics, piston friction losses, friction and side force are presented. For the simulated AVL FRISC engine, the measurements of LOC, blow-by, FMEP, friction and side forces are available and simulation results are compared with the available measurements. Finally, a study on tuning parameters for results correlation and sensitivity of tuning parameters is presented.

• Keywords: trenje klipnog mehanizma; mjerenja AVL FRISC; AVL EXCITE™ Piston&Ring; AVL EXCITE™ Power Unit; srednji tlak gubitaka; potrošnja ulja; prestrujavanje zraka; sila trenja; bočna sila na klipu; tangencijalna sila klipnog prstena; 2D i 3D pristup; REVO; EHD; utjecaj parametara
• Keywords (english): piston group friction; AVL FRISC measurement; AVL EXCITE™ Piston&Ring; AVL EXCITE™ Power Unit; FMEP; LOC; blow-by; friction force; side force; tangential force on piston ring; 2D and 3D simulation solver; REVO; EHD; tuning parameters
• Language: croatian
• URN:NBN: urn:nbn:hr:235:758581
• 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: 2024-02-02 16:25:09