FAST RIDES SHOWCASE

An automobile is a wheeled vehicle with a self-contained motor that runs mostly on roads. Automobile speed is an outcome of four interacting factors: power, power train, weight and aerodynamics.

Power

The motive force for a car is the engine. Every engine produces an amount of work-energy measured in mechanical horsepower. One horsepower is 550 foot-pounds per second. More power in generation from the engine means more power available to turn the wheels faster on the car.

Power Train

A car with a 100 horsepower engine still has to have the energy from the engine transferred to the mechanical axle to turn the wheels. The mechanisms that effect this transfer are called the power train. Reduction of friction and resistance throughout the power train will make more energy available to turn the wheels, and thereby increase speed.

Weight

Two equally powerful engines, with two equally efficient power trains, and unequal weights will have different top speeds because of the difference in weight. Lighter weights translate into more speed.

Aerodynamics

Air causes greater resistance at increasing speed. The faster you go, the more air you are moving in a given amount of time. Air resistance to automobiles increases progressively with speed. Aerodynamic design that reduces wind resistance increases car speed.

Reaction Turbines

Reaction turbines and water wheels, a type of turbine, are very efficient machines. Because of their unique design, maximum energy is extracted from the flowing stream. This leads to offshoot advantages, such as improved power transfer to pulleys or grinding stones. In 2011, all turbines are reaction, since other types of turbines are inefficient and antiquated technology.

Efficiency Advantage

Because the blades of a reaction turbine direct nozzle flow opposite the spin, an action / reaction physics process takes place. This is very much akin to filling a balloon with air and letting it go. The escaping air forces the balloon in the opposite direction. Engineer J. B. Calvert of the University of Denver describes an S-shaped lawn sprinkler as a reaction device. In terms of energy input versus energy output, a reaction turbine is far more efficient than the old-style impulse turbine, which just had the force of the liquid from the nozzle hitting paddle blades.

Energy Input Advantage

In comparing an impulse turbine to a reaction turbine, you find the energy inputs are different. To extract the same amount of power output from an impulse turbine, you need a lot more energy input. For a gravity-fed water system, this means the water has to fall a greater distance for an impulse turbine. For a steam turbine system, more steam is required for an impulse turbine.

Materials Usage Advantage

Because the efficiency is greater for a reaction turbine over an impulse turbine, not as many materials are needed to build a reaction turbine that produces the same energy output. An impulse turbine would require a bigger housing, more paddles and a larger diameter. All this translates into more materials, and more materials cost to build an impulse turbine.

Power Output Advantage

For the same size of turbines, a reaction turbine puts forth more power than an impulse turbine. Impulse turbines are simply not efficient in terms of energy output. For this reason, impulse turbines are antiquated technology and no longer used in modern turbine systems, such as a steam-powered electrical generating facility.