1. HONG IK UNIVERSITY 2008 -2009 Webinar presentation for Emerging Market Vehicle Project July 21 2009

2. HONG IK UNIVERSITY 2008 -2009 Agenda Overall background Improvement in CAD model & meshing Result of Force values (C D, C L ) & Shape of wake Comparison & Analysis Conclusion

3. HONG IK UNIVERSITY 2008 -2009 Overall Background Our EMV vehicle is a van-type exterior. - C D value for this shape is approximately 0.5 Reduce the C D value. - Not easy to reduce the frontal area of a van-type vehicle. - A hybrid vehicle needs an energy-efficient powertrain. Decrease wake. - A lower pressure zone is generated when wake is distinctly developed.

4. HONG IK UNIVERSITY 2008 -2009 Received EMV CAD model (March 20 th ) Checking the CAD model for running CFD, Overall Background

5. HONG IK UNIVERSITY 2008 -2009 Surface meshing (April 7 th ) - 2D mesh by Hyper works Volume meshing (May 4 th ) - 3D mesh by Tgrid Overall Background

6. HONG IK UNIVERSITY 2008 -2009 1 st CFD results (May 16 th ) < Pathlines colored by Particle ID > C D : 0.4657 (Axis : +Y) C L : - 0.1855 (Axis : +Z) Extreme wake at the back side Overall Background

7. HONG IK UNIVERSITY 2008 -2009 Improvement the CAD model & meshing(1) The model for reducing the C D value & wake Concept1Concept2 Model 2 Model 1

8. HONG IK UNIVERSITY 2008 -2009 Improvement the CAD model & meshing(2) Meshing for update-model Model 2 Model 1

9. HONG IK UNIVERSITY 2008 -2009 Improvement the CAD model & meshing(3) CFD model descriptions Update model Elements #4,672,738 Inlet Velocity120 km/hr Model descriptionsSymmetric model, Considering ground effect Frontal area 2.49 ㎡

10. HONG IK UNIVERSITY 2008 -2009 Result of Force values (C D, C L ) & Shape of wake(1) Baseline model results - C D : 0.4657 C L : - 0.1855

11. HONG IK UNIVERSITY 2008 -2009 Result of Force values (C D, C L ) & Shape of wake(2) Baseline model

12. HONG IK UNIVERSITY 2008 -2009 Result of Force values (C D, C L ) & Shape of wake(3) Update-model - C D : 0.4536 C L : - 0.1603

13. HONG IK UNIVERSITY 2008 -2009 Result of Force values (C D, C L ) & Shape of wake(4) Update-model

14. HONG IK UNIVERSITY 2008 -2009 Comparison & Analysis Baseline modelUpdate modelImprovement(%) CDCD 0.46570.45362.59 CLCL - 0.1855- 0.160313.58 WakeSignificant wake reduction Comparison

15. HONG IK UNIVERSITY 2008 -2009 Conclusions By attaching a small protrusion on the rear part of the roof,  achieved the reduction of wake phenomena  So does drag coefficient!! As a result, we could simply improve the quality of aerodynamical efficiency by not changing much the form of existing van.

16. HONG IK UNIVERSITY 2008 -2009 Thank you