Analiza otpora zraka i njegov utjecaj na potrošnju goriva kod pojednostavljene geometrije autobusa

master's thesis

• Title (english): Analysis of air drag and its influence on the fuel consumption for the simplified bus geometry
• Author: Matej Bošković
• Mentor: Momir Sjerić (mentor)
• Granter: University of Zagreb; Faculty of Mechanical Engineering and Naval Architecture; Zagreb
• Defense date and country: 2025-02-10, Croatia
• Scientific / art field, discipline and subdiscipline: TECHNICAL SCIENCES; Mechanical Engineering; General Mechanical Engineering (Construction)

Abstract

U ovom radu objašnjen je detaljan postupak izrade modela i postavljanja simulacije za pregled ovisnosti faktora otpora zraka o radijusu zaobljenja prednjega gornjeg ruba autobusa u programskom paketu ANSYS te njegov utjecaj na potrošnju goriva u programskom paketu CarSim. Uvodni je dio povijesni pregled kako se mijenjao oblik vozila te i sam faktor otpora zraka te što utječe na potrošnju goriva. Zatim se objašnjava izrada geometrijskih 2D i 3D modela vozila i kako se postavlja računalna simulacija dinamike fluida. Potom se opisuje i objašnjava postupak izrade simulacijskog modela za analizu dinamike vozila. Poslije toga prikazani su i analizirani rezultati ispitivanja. Analizom rezultata se pokazalo kako pojedini dijelovi utječu na otpor zraka, kako je raspoređen faktor tlaka po konturi vozila, tj. kako i koliko pojedini dio na vozilu utječe na otpor zraka i kako različite vrijednosti faktora otpora zraka utječu na potrošnju goriva i emisiju . Na kraju rada je naveden zaključak u kojem je vidljivo da već malom promjenom zaobljenja prednjeg gornjeg brida dolazi do znatne promjene faktora otpora zraka te kako povećanje zaobljenja i faktor otpora zraka nisu proporcionalni. tj. kako se sve većim povećanjem zaobljenja ne smanjuje sve više faktor otpora zraka. Također se uočilo kako je i s ograničenim resursima studentske verzije moguće dobiti približne vrijednosti kao i u realnim uvjetima. Dokazalo se kako povećanje faktora otpora zraka znatno utječe kod vožnje autocestom, tj. vožnje većim brzinama, a da kod gradskog i međugradskog režima, tj. kod vožnje manjim brzinama, ne utječe znatno.

Abstract (english)

This paper describes the comprehensive process for building a model and configuring a simulation to investigate how the air resistance factor depends on the bus's front upper edge's radius of curvature in the ANSYS software package and how it affects fuel consumption in the CarSim software package. The introduction provides a historical review of the changes in the vehicle's design and the air resistance factor itself, as well as the factors that influence fuel consumption. The construction of geometric 2D and 3D vehicle models is then described, along with the setup of a computer simulation of fluid dynamics. The process of developing a simulation model for fluid dynamics analysis is then discussed and described. After that, the steps involved in developing a simulation model for vehicle dynamics study are outlined and clarified. Following that, the test results are shown and examined. The results of the analysis demonstrated how the pressure factor is distributed along the vehicle contour, how and to what degree individual parts of the vehicle affect air resistance, and how fuel consumption and emissions are affected by varying air resistance factor values. The paper concludes by demonstrating that even a slight alteration in the front upper edge's curvature results in a notable change in the air resistance factor and that the two variables are not proportionate, meaning that decreasing curvature does not result in a decrease in air resistance factor. Additionally, it was noted that approximation values from real-world conditions could be obtained even with the student version's limited resources. Driving on highways, or at greater speeds, is significantly impacted by an increase in the air resistance factor, whereas driving in cities and between cities, or at lower speeds, is not much impacted.

• Keywords: aerodinamika autobusa; potrošnja goriva; faktor otpora zraka; vozni ciklus
• Keywords (english): bus aerodynamics; fuel consumption; air resistance factor; driving cycle
• Language: croatian
• URN:NBN: urn:nbn:hr:235:855689
• 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, Mechanics and Robotics, Autonomous Systems, Mechatronics and Robotics; Course: Design; Study programme type: university; Study level: graduate; Academic / professional title: sveučilišni/a magistar/magistra inženjer/inženjerka strojarstva (sveučilišni/a magistar/magistra inženjer/inženjerka strojarstva)
• Type of resource: Text
• File origin: Born digital
• Access conditions: Open access
• Created on: 2025-01-31 16:30:59