Ch 9. External Flow fl Multimedia Engineering Fluids Drag Lift BoundaryLayer
 Chapter 1. Basics 2. Fluid Statics 3. Kinematics 4. Laws (Integral) 5. Laws (Diff.) 6. Modeling/Similitude 7. Inviscid 8. Viscous 9. External Flow 10. Open-Channel Appendix Basic Math Units Basic Equations Water/Air Tables Sections Search eBooks Dynamics Statics Mechanics Fluids Thermodynamics Math Author(s): Chean Chin Ngo Kurt Gramoll ©Kurt Gramoll

 FLUID MECHANICS - CASE STUDY Introduction Problem Description Click to view movie (40k) Andy, the manager of EZ Trucking, would like to convince his boss to invest in installing air deflectors on their 18-wheelers. Research has shown that the drag coefficient, CD, is lower for an 18-wheeler with an air deflector (from 0.95 to 0.75). How can he show that the air deflector will save the company a small fortune? Questions What is the drag exerted on the 18-wheeler with and without the air deflector? Approach The drag force is directly proportional to the fuel consumption. Base the analysis on a frontal area, A, of 100 ft2. Assume the 18-wheeler runs at an average speed of 65 mph on the highway.