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Making current cars more efficient. Minimize the force required: ma+msg+ C r mv+C D A f v 2 /370 Make m small Make C r small Make C D small Make A f small Make v small Or any combination of reducing these values. Flex-Fuel Vehicles.

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making current cars more efficient
Making current cars more efficient
  • Minimize the force required:
    • ma+msg+ Crmv+CD Af v2 /370
  • Make m small
  • Make Cr small
  • Make CD small
  • Make Af small
  • Make v small
  • Or any combination of reducing these values
flex fuel vehicles
Flex-Fuel Vehicles
  • Internal combustion engines designed to run on more than one fuel
  • Second fuel is usually ethanol or sometimes methanol
  • Fuel blend is detected by sensors that adjust ignition and timing to match the mixture
  • Most North American vehicles are optimized to run on mixtures up to E85.
the first flex fuel vehicle was
The first flex fuel vehicle was
  • The Ford Model T!!!!
  • Designed to run on petroleum, ethanol or kerosene
  • Prohibition made ethanol unviable and decreasing costs of petroleum made it more attractive
  • 1909-1927
alternatives to the internal combustion engine
Alternatives to the internal combustion engine
  • Flywheels
  • Electric batteries
  • Hybrids
  • Alcohol
  • Hydrogen
flywheels
Flywheels
  • Energy storage device
  • Flywheel is spun up and the energy is stored as rotational energy to be used at a later time
  • Designed to resist losses of rotational energy due to friction, etc
  • Energy stored is given by
      • Ek = Iω2

where I = moment of inertial of the flywheel, and ω is the angular velocity.

  • The moment of inertial is a function of the mass and the distance from the center of rotation
  • So the structure of the flywheel and the rotational rate determine the amount of energy stored.
  • Ultimate limit on the energy storage is the strength of the flywheel. Spin it too fast, and it will tear itself apart.
flywheel vehicles
Flywheel vehicles
  • Could extract energy from braking-rather than waste the energy into frictional heating of brakepads, reverse the engine and spin up the flywheel.
  • Need to be recharged on the power gird, saves gas, but drains electricity
  • The big implementation problem is materials which can withstand the stress needed to spin the flywheel fast enough to make this a worthwhile alternative.
  • Prototype mass transportation vehicles have been built (In Sweden and by Lockheed)
  • Used in Formula 1 racing to recover energy lost in braking and along with a continuously variable transmission to improve Formula one car acceleration.
  • Also used in the incredible hulk roller coaster at Universal Islands of Adventure in Orlando, Fl.
    • Ride starts with an uphill acceleration, rather than a gravity drop.
    • Flywheels are used to provide the initial energy impulse, otherwise the park would brown out the local energy grid everytime the ride began.
hybrids
Hybrids
  • Still use gasoline powered engines, but combine them with (usually) batteries to achieve better fuel economy.
  • Different from a flex-fuel vehicle:Flexible fuel vehicles (FFVs) are designed to run on gasoline or a blend of up to 85% ethanol (E85).
    • no loss in performance when operating on E85.
    • FFVs typically get about 25-30% fewer miles per gallon when fueled with E85.
  • Idea is to use as small as possible a gasoline engine, and only when it can be run at peak efficiency.
  • Use excess power to recharge the battery (no need to tap the power grid)
  • Use energy from braking (regenerative braking) to also charge the battery
  • Work best in stop and go driving.
  • Major initiative in the auto industry right now.
  • Result in using less gas-stretching our fossil fuels
hybrid models
Hybrid Models
  • Hyunai Sonata Hybrid
  • Honda CRZ and Fit
  • Mercedes Benz ML 450
  • BMW
  • Dodge Ram
  • Chevy Silverado
  • Toyota Prius
  • Chevy Volt –WKU president drives one
    • has a total driving range of up to 379 miles. For the first 35 miles, it can drive gas free using a full charge of electricity stored in its 16-kWh lithium-ion battery. When the Volt’s battery runs low, a gasoline-powered engine seamlessly operates to extend the driving range another 244 miles on a full tank.
pure electric vehicles
Pure electric vehicles
  • Powered by an electric motor, rather than a gasoline engine
  • Needs batteries – current generation of batteries have 520 times less energy density than gasoline.
  • Need to be charged from the power grid
  • If all the vehicles in the US were converted to electric cars, it would triple the current electric energy generation
  • Recharging electric vehicles takes time- several hours, whereas it takes minutes to refill your gas tank
  • Batteries have a finite lifetime, need to be replaced every 2-3 years at a current cost of 1000
  • Limited range (less than 100 miles before recharging is needed)
  • Ultimate limit is current battery technology-current lead acid batteries have not changed much in 100 years.
  • Environmental effects from the disposal of lead acid batteries
  • No new promising battery technologies on the horizon to substantially help electric cars
types of electric vehicles
Types of electric vehicles
  • Ford Focus EV due in late 2011
  • Nissan Leaf - out now
fuel cells
Fuel cells
  • An electrochemical conversion device
  • Chemical reactions cause electrons (current) to flow
  • Requires a fuel, an oxidant and an electrolyte ( a substance that contains free ions and acts as a conductor)
  • Typical type of fuel cell is called a proton exchange membrane fuel cell (PEMFC)
hydrogen fuel cells
Hydrogen Fuel Cells
  • Clean-only emission is water
  • Expensive to produce
  • Highly efficient-in an automobile, efficiencies of converting fuel energy to mechanical energy of 60% could be achieved, almost double the current efficiencies
  • Hydrogen itself has issues as a fuel source
issues with hydrogen
Issues with Hydrogen
  • Abundant in nature, but not a freely available fuel
  • Must be unbound from compounds
  • Currently obtained via steam reforming
    • Steam and a nickel catalyst react, producing H
    • Need steam at very high temperatures, 1600F
  • In the future, H is anticipated to be produced by the electrolysis of water, requiring large amount of water and electricity
electrolysis
Electrolysis
  • Pass an electrical current through water and obtain H
  • Pass a direct current from a battery or other DC power supply through a cup of water (salt water solution increases the reaction intensity making it easier to observe).
  • Using platinum electrodes, hydrogen gas will be seen to bubble up at the cathode, and oxygen will bubble at the anode.
  • Choice of the electrode is critical, you do not want a metal that will react with oxygen
issues with hydrogen1
Issues with Hydrogen
  • Storage-occurs in gas form at room temperature, hard to contain
  • As a liquid, it can be stored, but needs temperatures of -253 C.
    • As a liquid, its energy density increases 1000 times
    • In principle, could replace gasoline as a liquid fuel, but not practical at this time
  • One solution is to store it as a metallic hydride (the negative ion of Hydrogen in a compound with another element) at room T.
issues with h
Issues with H
  • Highly explosive
    • Forms a volatile mixture with air
  • A mixture of 4-75% of H in air is explosive, compared with natural gas which is only explosive in a range of 5-15% concentration in air
  • Ignition energy is small, needing only 2 x 10-5 J (basically a spark of static electricity can ignite H)
  • Only good news is its low density means if there is a H leak, it disperses quickly
hydrogen
Hydrogen
  • Hindenburg disaster
  • Hindenburg was a German passenger airship (zeppelins) built for transatlantic air flight.
  • Filled with Hydrogen
  • Something caused ignition of the Hydrogen-cause is debatable
  • 36 fatalities out of 79 people onboard
alchohol
Alchohol
  • Use methanol or ethanol as a fuel
    • Already gone over ethanol
  • Methanol is already in use at Indy 500 race
    • Proven that no significant loss of performance is experienced (though they are in the process of switching to ethanol)
  • About ½ the energy content of gasoline
  • Produces only CO2 and water
    • Some nitrogen oxides produced in the engine
  • Can be manufactured from re-newable sources (biomass for example)
  • Technologies exist now.
disadvantages
Disadvantages
  • Very dangerous
    • Burns with no visible flame-needs a colorant added
    • Fumes are toxic
  • CO2 is a greenhouse gas
  • Currently made mostly from natural gas-a non-renewable fossil fuel
  • Possibly more corrosive than ethanol to engine parts
use in liquid fuel cells
Use in liquid fuel cells
  • Another use is as a input to a liquid feed fuel cell
  • In these cells, Methanol replaces hydrogen
  • Methanol has a much higher energy density and is easier to store than H
  • Current methanol fuel cells produce power too low for vehicles, but can be used in cell phones, laptops etc
  • Advantage is that they store lots of power in a small space, which they over a long period of time
environmental effects of energy production
Environmental effects of energy production
  • All of our energy producing mechanisms have some effect on the environment
    • Production of waste products pollutes air, water and ground
    • Disruptions to local ecosystems
  • Our job is to understand and mitigate these effects to the best of our ability
  • Philosophy : If it hurts (the environment) when you do that, don’t do that!
air pollution
Air pollution
  • If its in the air, its in your body
  • Components of the Earth’s Atmosphere:
    • Nitrogen 78.08%
    • Oxygen 20.95%
    • Argon 0.93%
    • Also small amounts of Neon, Helium, Krypton,& Hydrogen
  • In addition, there are compounds whose concentrations vary with height: water vapor, carbon dioxide, methane, carbon monoxide, ozone, ammonia
  • These are naturally occurring concentrations, any additional influx or destruction of these compounds via human beings alters the system.
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