Computational Evaluation of Aerodynamic Performance of Isuzu Midi Bus Body

Abstract

The aerodynamic drag reduction problem is a major topic in the automotive industry because of its close link with reduction of fuel consumption and exhaust emission. Many buses travel large distances at higher speeds. The significant increase in road transport combined with the increasing environmental issues and fuel prices has renewed the interest in bus design. Reducing the aerodynamic drag has a large positive influence on the fuel economy and the reduction of harmful exhaust gases. There are many buses available in Ethiopia most of these buses have poor aerodynamic shape which seems rectangular blunt, which has high drag resistance force these leads to increased fuel consumption. Isuzu Midi Bus is one of the most available buses in Ethiopia, its outer exterior body is built locally with poor aerodynamic shape. The main objective of this study was to improve the outer body shape of the existing Isuzu Midi Bus aerodynamically in order to reduce the overall aerodynamic drag force which in turn results in reduction of fuel consumption and carbon dioxide emission. The analyses were performed both numerically using Computational Fluid Dynamic /ANSYS Fluent, and experimentally for validation using Wind Tunnel. A baseline model of the bus modeled with SolidWorks with scale of 1:20 was analyzed at various speeds and the coefficient of drag was found. Later modifications and addition of rear spoiler were made to this base design in order to reduce the coefficient of drag and lift. Four models such as model Ⅰ, model Ⅱ, model Ⅲ, and model Ⅳ were prepared. The coefficient of drag was later converted into quantifiable performance parameters such as fuel efficiency and CO2 emissions. The aerodynamic shape improvement in model Ⅳ reduced the drag coefficient by 54.35% which has resulted in the percentage reduction in fuel consumption of 32.61% and exhaust gas emission 9.7%. This reduction of exhaust emission has a significant effect in the environment.

The Aerodynamic Drag Reduction Problem Is A Major Topic In The Automotive Industry Because Of Its Close Link With Reduction Of Fuel Consumption And Exhaust Emission. Many Buses Travel Large Distances At Higher Speeds. The Significant Increase In Road Transport Combined With The Increasing Environmental Issues And Fuel Prices Has Renewed The Interest In Bus Design. Reducing The Aerodynamic Drag Has A Large Positive Influence On The Fuel Economy And The Reduction Of Harmful Exhaust Gases. There Are Many Buses Available In Ethiopia Most Of These Buses Have Poor Aerodynamic Shape Which Seems Rectangular Blunt, Which Has High Drag Resistance Force These Leads To Increased Fuel Consumption. Isuzu Midi Bus Is One Of The Most Available Buses In Ethiopia, Its Outer Exterior Body Is Built Locally With Poor Aerodynamic Shape. The Main Objective Of This Study Was To Improve The Outer Body Shape Of The Existing Isuzu Midi Bus Aerodynamically In Order To Reduce The Overall Aerodynamic Drag Force Which In Turn Results In Reduction Of Fuel Consumption And Carbon Dioxide Emission. The Analyses Were Performed Both Numerically Using Computational Fluid Dynamic /Ansys Fluent, And Experimentally For Validation Using Wind Tunnel. A Baseline Model Of The Bus Modeled With Solidworks With Scale Of 1:20 Was Analyzed At Various Speeds And The Coefficient Of Drag Was Found. Later Modifications And Addition Of Rear Spoiler Were Made To This Base Design In Order To Reduce The Coefficient Of Drag And Lift. Four Models Such As Model ???, Model ???, Model ???, And Model ??? Were Prepared. The Coefficient Of Drag Was Later Converted Into Quantifiable Performance Parameters Such As Fuel Efficiency And Co2 Emissions. The Aerodynamic Shape Improvement In Model ??? Reduced The Drag Coefficient By 54.35% Which Has Resulted In The Percentage Reduction In Fuel Consumption Of 32.61% And Exhaust Gas Emission 9.7%. This Reduction Of Exhaust Emission Has A Significant Effect In The Environment.