Journal 4-4 Max Bardowell 4-28-08

Most Efficient Blade Angle for Wind Turbines

Answer to Last Week’s Question: Tesla died of heart failure alone in Room 3327 of the New Yorker Hotel, some time between the evening of January 5 and the morning of January 8, 1943, at the age of 86. Despite selling his AC electricity patents, Tesla was destitute and died with significant debts. Later that year the US Supreme Court upheld Tesla's patent number U.S. Patent 645,576 in effect recognizing him as the inventor of radio.

wikipedia.com

Last week we were asked to design and then carry out a lab plan based around the wind turbine models we had built earlier in the week. Designs for our turbine called for a blade that was cupped toward the back edge of the blade in order to more effectively catch the wind. With the addition of this feature, we would also need to determine what angle, in relation to the front edge of the turbine, the blade should be turned to, to achieve the maximum output/ input efficiency. This was tested by recording the output energy at a series of different blade angles, from 30 degrees to 180 degrees, and then calculating the output efficiency for each. The 30 degree angle produced the highest output efficiency: .0276 watts, while the next highest angle, 45 degrees, only produced an efficiency of .0197 watts. My findings supported my hypothesis, as the wind passing over the blades at a 30 degree angle has the greatest combination of both blade surface area and catch. In order to produce a turbine with the most efficiency output, it is necessary to create a blade that has a cupped edge to catch the wind. However, you must first determine what angle, in relation to the front edge of the turbine, the blade should be turned to, to achieve the maximum output/ input efficiency. The results gained from this experiment could be very applicable to any future designs of wind turbines, where the maximum efficiency that can be gained from the least amount of material is optimal.

I also learned that the construction of your materials must be sound before you even design an experiment to surround them, as faulty equipment will disrupt the flow and findings of an experiment. I also learned that measurements must be precise, as flawed measurements will carry through the entire experiment, affecting the final results and thus the answer to the initial question posed.

Question: Who is the leading manufacturer of wind turbines?

Journal 4-3 Max Bardowell 4-20-08

Nikola Tesla

Answer to Last Week’s Question: A “wind farm” is any collection of more than one wind turbine that is operated in order to produce electrical power. The largest farms can have over one hundred turbines and can stretch for hundreds of square miles.

• There is a fine line between genius and madness. Explain how this might be said of Tesla. Give at least two examples.

I think that the two traits mentioned above are often found to be residing in the same individual, as was the case with Tesla. There is also a third complication to throw into the mix; obsession, a quality Tesla also shared. I think there is a fascinating common bond among many great men of science, that they all have genius mixed with another potentially negative quality. I say potentially because oftentimes these debilitating characteristics give them the power to accomplish the unimaginable. Such was the case with Tesla. He was a genius, but he was also a social introvert, obsessive to the point of madness, and so competitive that he would waste his life away to outdo another scientist. However, these qualities did not limit him; they allowed him to electrify the world. By opening himself up fully to the effects of these characteristics, he gained vision, and focus, and the drive to push the boundaries of the physical world we knew. He reversed their effects in a sense, using obsession to push his body and mind to the maximum, and madness to block out the world and open his mind to the possibilities before him. He could not however, reverse the effects of his status as a social outcast, a problem that eventually lead to his downfall. He could not speak, so the world did not listen.

Question: How and when did Tesla die?

Journal 4-2 Max Bardowell 4-16-08

Wind Turbines

Answer to Last Week’s Question: The Alternating Current system used today was devised in the late nineteenth century by Nikola Tesla.

This week we began construction of our wind turbines. During this process, as the design of our turbine began to take shape, I became interested in the history of wind turbines and how they came to be used in the manner which they are used today.

According to Wikipedia, machines powered by wind were used for grinding grain in Persia as early as 200 B.C. They were later used for the same function in the Roman Empire. By the 14^th century, windmills were being used for more advanced purposes in Denmark, such as to drain areas of the Rhine River delta. By 1900 in Denmark there were approximately 2500 windmills used for mechanical loads such as pumps and mills. The first windmill built for the production of electricity was constructed in Cleveland, Ohio in 1888, and by 1908 there were 72 wind-driven electric generators. The largest machines were on 79 ft towers with four-bladed 75 ft diameter rotors. Around the time of World War I, windmill makers in America were producing 100,000 windmills each year, most for water-pumping actions. By the 1930s, windmills for the production of electricity were common on farms.

The forerunner of modern wind generators was in service at Yalta, Russia in 1931.

Question: What are “wind farms” ?

Journal 4-1 Max Bardowell 4-6-08

The War of the Currents

In one of our recent discussions about electricity we talked about the two different forms of electricity, alternating and direct current. I was puzzled by the fact that Thomas Edison, the man responsible for inventions such as the light bulb and the phonograph, would support direct current, the variant of electricity that is considered less sophisticated and less successful, as it is no longer in use today. After some research I discovered that the time after electricity’s conception, when it was still an immature technology, became defined by the “War of the Currents”, the struggle between Edison and George Westinghouse over which of the currents the public would accept. I am still not sure why Edison supported direct current, as even then it was widely considered an inferior technology, but I have a theory that he simply felt duty bound to support his invention through thick and thin. He could have just been a stubborn man. The time period is very interesting, fraught with competing inventors and progress, and is a large part of popular culture, inspiring movies such as The Prestige.

Question: Who was the inventor of Alternating current?

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Home Energy Use

Answer to Last Week’s Question: Past Rube Goldberg challenges:

Past Contest Challenges:

• 1987 Put Toothpaste on a Toothbrush
• 1992 Unlock a Combination Padlock
• 1997 Insert and Then Play a CD Disc
• 2002 To Select, Raise and Wave a National Flag
• 2004 To Select, Mark and Cast an Election Ballot (certainly applicable to today)
• 2007 Squeeze the Juice from an Orange

This week we conducted an energy survey of our homes. The survey begins with questions about the floor plan of our homes, how old it is, how large it is, what heating system we use, and finally whether we rent or own our home. Next it uses more detailed questions to determine what types of appliances we use. Using this information the survey found that my house used about an average amount of energy.

It then suggested some cost cutting solutions that we could employ to reduce our energy footprint. Naturally many of these centered around improving the heating and colling system, as this draws the overwhelming majority of energy. They suggested lowering the hot water heater temperature, insulating the hot water heater, washing full loads of dishes, air drying dishes, avoiding over drying clothes, maintaining the heating system, installing a programmable thermostat, and finally using compact florescent light bulbs. These simple cost cutting solutions will hopefully help reduce our effect on the environment and promote a longevity within our natural resource consumption.

Question: Who developed and who maintains this surveys website?

Rube Goldberg Devices

Answer to Last Week's Question: The first major discovery or invention conceived by early humans is arguably the domestication of animals and the use of irrigation in agriculture, both of which would have undoubtedly revolutionized their society.

After learning that we would soon be developing our own Rube Goldberg devices in class, I decided to research a little about this extraordinary man and his life. Goldberg began his career as an engineer, graduating from Berkley in 1904. From there he began a distinguished career in cartooning, working at papers of the caliber of the San Francisco Chronicle and incorporating his experience as an engineer into his cartoons. His career culminated in his reception of the 1940 Pulitzer Prize for political cartooning. Unfortunately later in life his cartoons became so controversial in the WWII era he was forced to change his name and to go in to hiding. Accounts of his life after that point become sketchy. He died on December 7^th, 1970.

The cartoon series his is best known for, the “Professor Butts” collection, utilized Goldberg’s knowledge of engineering, physics and the flow of energy to construct theoretical machines that would perform simple tasks. His designs gave rise to many copycats and later to design contests which encourage students to explore the three dimensional world of energy as opposed to the linear one. His designs also prompted our project.

Question: What tasks have students been required to complete in past Rube Goldberg challenges.

Below is the the "Cog" advertisement developed by Honda, a classic example of a Rube Goldberg machine.

Energy/ Connectivity within Physics


“In physics, you don't have to go around making trouble for yourself - nature does it for you.”

Frank Wilczek

“The observer, when he seems to himself to be observing a stone, is really, if physics is to be believed, observing the effects of the stone upon himself.”

Bertrand Russell

How true. Each energy experiment we conducted this week revealed a bit more about the world around us, and, as we learned more about the world around us, we learned more about our place in it, and thus more about ourselves. It is this fluid and adaptive connectivity that makes the study of physics so unique, and in turn so difficult, hence the first quote presented here by Frank Wilczek. It seems that the more we discover about the physical world, the less we really know about it. The knowledge we gain coincides with the number of questions we unearth, and with questions come the desire for more discovery and more knowledge. Thus, the process perpetuates itself. But can we stop this process? Do we even want to? Are we debasing ourselves by preventing the search for knowledge? It seems as if there is no halting exploration. We are human, and humanity must ask why.

But, what can we learn from our constant questions? How can we find practical applications for the knowledge we gain? For instance, in the recent energy lab we completed, the first experiment involved a 50 gram mass attached to the end of a medium tension spring. The mass was raised to a certain height above the equilibrium point and then released. As the mass was released it began to bob and then slow to a halt. We inferred that the mass slowed due to the fact that the gravitational energy it possessed at the beginning of the experiment was lost over time. It simply dissipates into the atmosphere around it. What can we do with this new information? Fortunately, this fundamental fact can be applied to many industries and areas outside of physics. This can be applied to the area of car design, as the constant energy loss must be factored into any new design. Also with any type of sound proofing system or body armor system the effects of dissipating energy must be factored into design, as the force of sound waves or a bullet can carry far beyond the point when the sound can no longer be heard or the bullet has stopped moving. Thus, the theories of physics can have effects far beyond the text of their original phrasing. We can solve problems through discovery and experimentation, and if we’re lucky, our discoveries can change the world.

Answer to last week’s question: Hooke's law is named after the 17^th century British physicist Robert Hooke. He first stated this law in 1676 as a Latin anagram, whose solution he published in 1678 as Ut tensio, sic vis, which means:

“As the extension, so the force.”

For systems that obey Hooke's law, the extension produced is directly proportional to the load.

http://en.wikipedia.org/wiki/Hooke's_law

Question: What was the first major discovery made by early humans about the physical world?