Presentation on theme: "TRANSPORTATION. Energy Use By Sector Electric Utilities35.6% (1/3) Transportation28.4% (1/3) Industrial/Residential And Commercial 36.1% (1/3)"— Presentation transcript:
Energy Use By Sector Electric Utilities35.6% (1/3) Transportation28.4% (1/3) Industrial/Residential And Commercial 36.1% (1/3)
► 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.
How many cars does your family own? More than 4
Do you use the free bus service provided by ISU? 1. Frequently 2. Occasionally 3. Not at all
Do you have a car at ISU? 1. Yes 2. No
► 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%
Fuel Source for Transportation
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
Percentage of Energy for Different Transport Modes
Forces on a Moving Vehicle
Rolling Resistance Coefficients Rolling Resistance Coefficient Cr – 0.002Railroad steel wheels on steel rails 0.001Bicycle tire on wooden track – 0.005Low resistance tubeless tires 0.002Bicycle tire on concrete 0.004Bicycle tire on asphalt 0.005Dirty tram rails – 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
Energy usage in a typical car Heat losses in water and exhaust are due to 2nd Law (Carnot efficiencies)
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.
► Aerodynamic drag depends on shape and speed ► All other forces depend on mass ► Reduce mass reduce force opposing motion increase economy
2.1 - a smooth brick a typical bicycle plus cyclistbicycle Hummer H2, 2003Hummer H Citroën 2CVCitroën 2CV Lamborghini Countach, 1974Lamborghini Countach Ferrari Testarossa, 1986Ferrari Testarossa Chevrolet Caprice, Chevrolet Caprice Chevrolet Corvette Z06, 2006Chevrolet Corvette Z Chevrolet Camaro, 1995Chevrolet Camaro Audi A3, 2006Audi A Subaru XT, 1985Subaru XT BMW 8-Series, 1989BMW 8-Series Porsche Boxster, 2005Porsche Boxster Chevrolet Corvette, 2005Chevrolet Corvette Mercedes-Benz W203 C-Class Coupe, Mercedes-Benz W203C-Class Coupe Toyota Camry and sister model Lexus ES, 2005Toyota CamryLexus ES Porsche 997, 2004Porsche Toyota Camry Hybrid, 2007Toyota Camry Hybrid Toyota Prius, 2004Toyota Prius Honda Insight, 1999Honda Insight Audi A2 1.2 TDI, 2001Audi A General Motors EV1, 1996General Motors EV Ford Probe V prototype, 1985Ford Automobile_drag_coefficient
All other forces depend on mass
► Reduce mass reduce safety
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
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
CAFE Results ► fuel economy rose as the CAFE standard rose dramatically; price of fuel increased ► fuel economy rose as the CAFE standard rose; price of fuel decreased rapidly ► fuel economy rose at significantly subdued rate then leveled off; fuel fell, CAFE standard was relaxed
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.
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.
Efficiency vs. Max Load ► Engine are most efficient when they are running near max load.
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.
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.
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.,
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
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)