1. TRANSPORTATION

2. Energy Use By Sector Electric Utilities35.6% (1/3) Transportation28.4% (1/3) Industrial/Residential And Commercial 36.1% (1/3)

3. ► One of the three basic energy use sectors.  Electric Utilities  Transportation  Industrial, Residential, and Commercial ► Important for people and for goods. ► Changes in transportation costs can affect the cost of just about everything.

4. How many cars does your family own? 1. 0 2. 1 3. 2 4. 3 5. 4 6. More than 4

5. Do you use the free bus service provided by ISU? 1. Frequently 2. Occasionally 3. Not at all

6. Do you have a car at ISU? 1. Yes 2. No

7. ► There are approximately 200,000,000 cars trucks and buses in the US. ► Together, roads and parking account for approximately 1% of the land surface of the US. An area approximately equal to Indiana. ► Transportation uses almost 70% of the total petroleum used in the US.  Petroleum 97%  Other 3%

8. Fuel Source for Transportation

9. Energy Density of Various Fuels Storage TypeEnergy Density (MJ/kg) Gasoline46.4 Natural Gas53.6 NiMH battery0.25 Lead Acid Battery0.14 Li Ion Battery0.46 to 0.72 Hydrogen143 Antimatter89,876,000,000

10. Percentage of Energy for Different Transport Modes

12. Forces on a Moving Vehicle

13. Rolling Resistance Coefficients Rolling Resistance Coefficient Cr 0.001 – 0.002Railroad steel wheels on steel rails 0.001Bicycle tire on wooden track 0.002 – 0.005Low resistance tubeless tires 0.002Bicycle tire on concrete 0.004Bicycle tire on asphalt 0.005Dirty tram rails 0.006 – 0.01Truck tire on asphalt 0.008Bicycle tire on rough paved road 0.01 – 0.015Automobile tires on concrete 0.03Automobile tires on tar or asphalt 0.04 – 0.08Automobile tires on solid sand 0.2 – 0.4Automobile tires on loose sand

14. Energy usage in a typical car Heat losses in water and exhaust are due to 2nd Law (Carnot efficiencies)

15. How Can We Reduce Forces ► F tot =F a + F h + F r + F ad ► Don’t go up hills. (Works around here.) ► Go at constant speeds. ► Improve engineering (reduce C r & C D.) ► Reduce mass.

16. Power

17. Aerodynamic Drag

18. ► Aerodynamic drag depends on shape and speed ► All other forces depend on mass ► Reduce mass  reduce force opposing motion  increase economy

19. 2.1 - a smooth brick 0.9 - a typical bicycle plus cyclistbicycle 0.57 - Hummer H2, 2003Hummer H2 0.51 - Citroën 2CVCitroën 2CV 0.42 - Lamborghini Countach, 1974Lamborghini Countach 0.36 - Ferrari Testarossa, 1986Ferrari Testarossa 0.34 - Chevrolet Caprice, 1994-1996Chevrolet Caprice 0.34 - Chevrolet Corvette Z06, 2006Chevrolet Corvette Z06 0.338 - Chevrolet Camaro, 1995Chevrolet Camaro 0.33 - Audi A3, 2006Audi A3 0.29 - Subaru XT, 1985Subaru XT 0.29 - BMW 8-Series, 1989BMW 8-Series 0.29 - Porsche Boxster, 2005Porsche Boxster 0.29 - Chevrolet Corvette, 2005Chevrolet Corvette 0.29 - Mercedes-Benz W203 C-Class Coupe, 2001 - 2007Mercedes-Benz W203C-Class Coupe 0.28 - Toyota Camry and sister model Lexus ES, 2005Toyota CamryLexus ES 0.28 - Porsche 997, 2004Porsche 997 0.27 - Toyota Camry Hybrid, 2007Toyota Camry Hybrid 0.26 - Toyota Prius, 2004Toyota Prius 0.25 - Honda Insight, 1999Honda Insight 0.24 - Audi A2 1.2 TDI, 2001Audi A2 0.195 - General Motors EV1, 1996General Motors EV1 0.137 - Ford Probe V prototype, 1985Ford Automobile_drag_coefficient

20. All other forces depend on mass

22. ► Reduce mass  reduce safety

23. CAFE Standards ► Corporate Average Fuel Economy ► Regulations enacted by Congress in 1975 ► Intended to improve average fuel economy of cars and light trucks ► Vehicles under 8500 lbs/3856 kg

24. CAFE Standards

25. CAFE Testing ► The city and highway tests performed under mild climate conditions (75  F) ► Acceleration rates and driving speeds EPA believes are generally lower than real world conditions. ► Acceleration rates and driving speeds EPA believes are generally lower than real world conditions. ► No accessories (such as air conditioning) ► Highway test has a top speed of 60 mph

26. CAFE Results ► 1979-1982 - fuel economy rose as the CAFE standard rose dramatically; price of fuel increased ► 1984-1986 - fuel economy rose as the CAFE standard rose; price of fuel decreased rapidly ► 1986-1988 - fuel economy rose at significantly subdued rate then leveled off; fuel fell, CAFE standard was relaxed

27. CAFE Results

33. Maximum Load ► The power that an engine can provide depends on the engine rpm. ► The greatest power an engine can provide at a given rpm in the maximum load for that rpm.

34. Maximum Load ► The power that an engine can provide depends on the engine rpm. The maximum load is the maximum power that the engine can generate at a given speed: e.g. at 3000 rpm, the max load is 100 hp.

35. Efficiency vs. Max Load ► Engine are most efficient when they are running near max load.

36. Efficiency vs. Maximum Load ► Engine are most efficient when they are running near their maximum load. ► Maximum load is often not needed to cruise at a given speed ► More power is needed to accelerate and to run accessories.

37. Example of the effects of an overpowered car ► Previous slides are for a typical 3500 lb car. ► At 70mph the power required is 25hp and the engine is running at 3000 rpm. ► The max load at 3000 rpm is 100hp thus we have a partial load of only 0.25 and thus our efficiency is only 19%. ► If we use a smaller engine our partial load increases and we get better efficiency ► If we use a more powerful engine, the partial load is decreases and we get worse efficiency.

38. Techniques to improve efficiency ► Only use some of the cylinders when cruising. Others engage when you need more power. ► Use two engines: example Hybrid cars that combine gas and electric motors.,

39. Techniques to improve efficiency ► Only use some of the cylinders when cruising. Others engage when you need more power. ► Use two engines: example Hybrid cars that combine gas and electric motors., ► The Stirling cycle engine has the highest theoretical efficiency of any thermal engine Stirling cycle engineStirling cycle engine

40. Characteristics of the worst case car ► Very Heavy (increases forces due to rolling friction, acceleration, and hill climbing.) ► Boxy (increases aerodynamic drag) ► Overpowered (decreases partial load efficiency)