DRAG FORCE ANALYSIS OF CAR

1
DRAG FORCE ANALYSIS OF CAR AUTHORS
ABHISHEK KUMAR RAVISHEK KUMAR
SESSION 2005-2006 DEPARTMENT OF MECHANICAL
ENGINEERING G. H. RAISONI COLLEGE OF
ENGINEERING, NAGPUR.
2
CONTENTS

• Introduction
• Motivation
• Regimes of External Flow
• Profile Drag
• Minimizing Drag on a LMV
• Expression For Drag Force
• Stream-lined and Bluff Body
• Components of Drag
• Thrust Vs Speed of Car
• Project
• Limitations
• Conclusion
• References

3
INTRODUCTION

• Decreasing the fuel consumption of road vehicles
  .
• Drag is one of the most important issues when it
  comes to Aerodynamics design of road vehicles

4
MOTIVATION

• Designing a vehicle with a minimized drag
  resistance provides economy and performance
  advantages.
• The main motivation for reducing drag resistance
  is
• Fuel consumption reduction
• Performance increasing

5
REGIMES OF EXTERNAL FLOW
External Flow of Fluid on Vertical Plate
6
External Flow of Fluid on Horizontal Plate
7
PRESSURE RECOVERY
8
PROFILE DRAG

• Pressure drag
• Friction drag
• Profile drag Pressure drag Friction drag

9
Expression For Drag Force

• The Drag force value for a moving vehicle is
  given by the following expression.
• DF 1/2 A ? CD V2
• where ,
• CD is the drag coefficient
• A is the projected frontal area of the vehicle
• ? is the density of air
• V is the speed of the vehicle relatively to the
  air

10
STREAM-LINED AND BLUFF BODY
11
MINIMIZING DRAG ON A LMV(CAR)
SHAPE OF VEHICLES BODY
12
DRAG COMPONENTS
13
THRUST Vs SPEED OF CAR
14
PROJECT
DIMENSIONS OVERALL LENGH 3335 mm
OVERALL WIDTH 1440 mm
2D SCETCH OF MARUTI 800
15
LIMITATIONS

• Space Constraint
• Styling may be the most flagrant example
• Consumers/buyers always seek for a
• certain look'. This concept is today very
• different from the aerodynamically ideal
• car.
• Drag and Lift Relation

16
CONCLUSION

• Smooth vehicle shape, rounded corners.
• Tapered rear end.
• Minimized body seams.
• Substitution of rear view mirrors with
  Cameras.
• Smooth underbody.

17
REFERANCES

• 1. Paper Optimization of Body Shape through
  Computation of Aerodynamic Forces on Low Mass
  Vehicle (LMV) By Inchul Kim and Xin Geng
• 2. Paper Reducing Drag Forces in Future
  Vehicles by Alexander Diehl, Jose Nuno Lopes, Rui
  Miranda, Christoffer Mursu Simu and John Viji.
• 3. Book Fluid Mechanics By John f Douglas,
  Janusz M Gasiorek and John A Swaffield.
• 4. Websites www.engin.umd.umich.edu/ceep/tech_day
  
• www.marutiudyog.com
• www.princeton.edu/asmits/blun
  t.html

18

• ANY QUERY ?

19

• THANK YOU