by Pepper White
I was counting incandescent light bulbs in a hallway at URI on the day of the Chernobyl nuclear accident. The bulbs were to be replaced by compact fluorescent bulbs, that would produce about 70 percent savings in electric use, while giving the same amount of light. As I watched on TV the brave Soviet firefighters lamely try to douse the out-of-control atoms, I felt like I'd picked the right side of the energy issue.
From that company a headhunter "placed" me at a small energy consulting firm in downtown Boston. It had been founded by two Harvard students during French class.
I worked at the consulting firm for six years, until June 1992. It was a boom time for such firms, before electric deregulation, and the electric utilities were spending money hand over fist to keep the regulators happy and to defer the need to build new power plants. The firm grew from 12 employees to 80, and I rose up the corporate ladder. I was never satisfied with my bosses there though, because once you've worked for the likes of John B. Heywood and Chet Yeung, it's hard to work for anyone else.
Two events convinced me that it was time to go out on my own. First, the company made me a branch office manager in Burlington, Vermont, in the winter and spring of 1992. It was just me and an about-to-retire engineer from the area. I was his boss. I was out of the cocoon where I had been made to believe that everything I produced had to be read, checked, modified, and proofread by eight different people.
The primary electric utility client up there asked for an analysis relating to air compressors. In less than an hour I typed up a summary memo, no longer than a page and a half, on an old NEC 286 using WordPerfect for DOS, and faxed it to them. They loved it, and referred to it as a model for months afterward.
The second event was the pond-skimming at the Sugarbush Ski Resort. Sugarbush is less than an hour from Burlington, and I frequented it on weekends. The lift operators and snow-making machinery operators build a dam out of snow at the bottom of the ski hill and make a pond. You start a few hundred feet above the pond, ski toward it, and try to keep your balance as you go from snow skier to water skier. If I can get myself to do this, I thought, then-sink or skim-I'll quit my job to go out on my own.
I skimmed about 40 feet, then rocked forward, then back, and then fell flat on my face about 60 feet down the 100 foot pond. However, I did it gracefully enough to come in fourth in the competition, and I won an attractive green Poland Spring sweatshirt. I'm hoping someday to lose enough weight to fit in it again.
I gave my notice to the Boston consulting firm, and I left on good terms. At first being self-employed felt like what I imagined the freefall part of bungee jumping to be like. What am I doing this for? But then a project came in, and then another, and now eight and a half years later I'm happier when the phone doesn't ring than when it does. That way I can work down my backlog.
During the free-fall phase of self-employment, I undertook what I refer to as my "personal life makeover." I thoroughly cleaned my rent-controlled Cambridge studio apartment. I hired an organizational consultant, organized my work files into hanging files with tabs, and started balancing my checkbook. My mother told me that if you build the nest, the little thrush will arrive."
My consulting projects include the occasional lighting survey, setting up Lotus or Excel spreadsheet models to calculate energy savings from various projects, estimating costs of the projects, and writing reports for the facilities staff. I also analyze trends in utility data, find ways to combine meters and streamline utility accounting, and look for rate changes that will save my clients money. Come to think of it, I wrote my own ticket. MIT allowed me to do that.
I've also been developing plans and specifications to solicit bids from contractors. I first wondered about my ability to do thatmost of the people who are good at it have worked at traditional A/E (architect/engineer) firms since they graduated from Northeastern or Wentworth. But I've become conversant with AutoCAD electronic drafting software and I've developed a fairly good library of specification language. And when I realize that "Plans and Specifications" can be translated to "Wheres/How Bigs and Whats/Hows," it doesn't seem so daunting. Also, I've discovered that "design" often just means "figure out where to put things."
April 30, 1999
Twentieth reunion, Johns Hopkins. I talk with a classmate who went on from Johns Hopkins to do very well at MIT and also in medical school. "You weren't harsh enough," he says. The whole system is corrupt. My thesis advisor took what I discovered in my thesis research and filed patents on it. He formed a company based on it and then sold it for millions of dollars. I didn't get a cent. I even hired a lawyer, but found out that a student has never won such a case."
June 25, 1999
Flying into Detroit Airport. I'm in the aisle seat. I like to be able to get up and go to the bathroom whenever I want to. A man is in the window seat and a woman is between us. They seem to be husband and wife.
I look out the window. A white stream trails the corner of one of the lowered flaps. Ah, I think. A tip vortex. The sharp point of the flap is causing the air flow over the wing to speed up and spin in the neighborhood of the point. As the flow velocity increases, Bernoulli tells us that the fluid's static pressure decreases. When it's really humid, as it is today in Detroit, the lower pressure and consequent lower temperature cause the water vapor's partial pressure to exceed its saturation pressure. A cloud-stream of minute droplets occurs.
I'm dying to share this with the couple to my right. But no, that would be weird. But yes the husband is explaining the phenomenon to his wife. The pilot must be releasing some fuel," he says.
Let it go, Pepper. Don't sweat the small stuff. Oh please. You idiot. Think about it. Are we about to crash land and the pilot wants to reduce the amount of JP-40 jet fuel that's available to burn? I don't think so. Can Northwest Airlines afford to throw away $3-a-gallon fuel every time a plane lands? Would the Environmental Protection Agency allow the unburned fuel to be released in this congested metropolitan area?
"Excuse me, but I couldn't help but overhear," I interrupt. You see, I studied fluid mechanics, and the phenomenon you're observing is called a tip vortex." I launch into an explanation.
"All I know is there's some kind of vapor out there," the husband says at last.
July 23, 1999
The air-conditioning in our 1990 Ford Escort doesn't work anymore, and the temperature is in the mid-90s during our drive back from our Vermont vacation. Daisy, our chocolate lab puppy, is breathing heavily. We stop at a service station, fill the empty gallon container with water, and I pour it on her regularly as we drive along. The evaporation of the water increases the rate of heat transfer away from her fur, and her breathing eventually becomes more normal.
What about the others? I last saw Chet when I asked him to review the technical material in this book. I had the spark plug explanation all wrong, which may partly explain why Schlumberger didn't hire me. Chet now has tenure. If anyone taught me how to solve problems, it was Chet, by example.
I sent a draft of the sections that included Gyftopoulos to him for his review. He corrected the technical errors, but by the tone of his red marks I sensed his displeasure. He left the rest of the text alone. When after the book was published I gave a talk for outgoing graduate students at MIT he was in the audience, beaming.
I finally got together with Nick in 1994. We went to the No Name fish restaurant on the South Boston waterfront for lunch. "You inventin' anything?" he asked me. He had confidence in me that I could invent things. If anyone taught me how to be a good person, it was Nick, by example.
Ben and my lab partner Scott became Ph.Ds and went on to work at General Motors. I hope to see them in Scientific American soon, featured as "The Men Behind the Work." Two Rapid Compression Machines are now in action. Which means that some mealymouthed 24-year-old kid is reading my thesis, and maybe this book, as background material. In the Eiffel Tower of technology, I am a rivet, or at least an atom or two in a rivet.
Doctor An retired after reaching t
he rank of colonel in the Israeli army. I last saw him in Manhattan in 1990. He'd lost 20 pounds or so and looked lean and kind and much healthier than he'd ever looked at MIT. His fellow countryman and MIT alum Bibi Netanyahu is still active in Israeli politics.
Shortly after Eldon graduated in 1986 his mother was afraid to leave him alone in the house-he was suffering from posttraumatic stress disorder. He didn't make the space program, but he did get a job at Lockheed programming automatic pilots. I went to his wedding in 1992, and he seemed very happy when I saw him and his wife a couple of years after that.
Dianne Mitchell is a composite of many Senior House boys and girls. I haven't been to Steer Roast in a long time, but I know that a kid that was a freshman when I started as a tutor joined the Foreign Service and became an ambassador within 10 years of completing his undergraduate degree, and another went to the '88 Olympics on the women's crew team and is now a professor of electrical engineering. Senior House itself has been gutrehabbed and the wall art has been lost forever.
At last report from a mutual friend, Stephanie was married and living in the Chicago area.
And Mary. Well, in the male-dominated world of engineering, I try to rebuke sexism in myself and others. It may be a little late, but I told her I'd try to make it up to her someday.
I try to be innocent. I try to be a nice person. I try not to be an egotist. I try to think like a human being.
Chapter Notes
CHAPTER 1
The Canoeing on Waves Problem. For visual understanding of water waves, consult Illustrated Experiments in Fluid Mechanics (the National Committee on Fluid Mechanics Films book of film notes), (Cambridge, Mass.: MIT Press, 1972.) The film, described on p. 105 of the book, is entitled Waves in Fluids, and was produced by Arthur E. Bryson of Harvard University. Books that discuss water waves include introduction to Physical Oceanography, by John A. Knaus, (Englewood Cliffs, N.J.: Prentice Hall, 1978); Marine Hydrodynamics, by J. N. Newman (Cambridge, Mass.: MIT Press, 1977), and Sea Loads on Ships and Offshore Structures, by 0. M. Faltinsen (Cambridge, Mass.: Cambridge University Press, 1990).
The Hot Hard-Boiled Egg Problem. This is an unsteady heat conduction problem. "Unsteady" means that throughout the egg, the temperature at each point changes with time. If you take the egg out of the cold water, it will feel hot until the whole egg is cooled off. Unsteady heat conduction in various geometries is discussed in Heat, Mass, and Momentum Transfer, by Rohsenow and Choi (Englewood Cliffs, N.J.: Prentice Hall, 1961), pp. 110-19.
CHAPTER 2
Fluid Mechanics. The text Fluid Mechanics, by Potter and Foss (New York: John Wiley & Sons, 1975) was recommended as a reference when I took 2.25. Also recommended was Physical Fluid Dynamics, by D. J. Tritton (New York: Van Nostrand Reinhold, 1977).
Thermodynamics. For further elaboration on the thermodynamic principles and definitions of concepts described in the lectures by Gyftopoulos, refer to: Principles of General Thermodynamics, by Hatsopoulos and Keenan, (Malabar, Fla.: Krieger Publishing [originally published by John Wiley & Sons, 1965] ); Thermodynamics, Foundations and Applications by Elias P. Gyftopoulos and Gian Paolo Beretta (New York: Macmillan, 1991); and the article in Encyclopaedia Britannica entitled "Thermodynamics, Principles of," by Hatsopoulos, Gyftopoulos, and Keenan. To save you a trip to the library, some terms are defined below. Definitions are drawn from lecture notes and/or class handouts for course 2.45 1, or where noted, from the McGraw Hill Dictionary of Scientific and Technical Terms, 2nd Edition.
State: The condition of a system at an instant in time, which encompasses all that can be said about the results of any measurements or observations that can be performed on the system at that instant in time.
System: Any identifiable collection of matter that can be separated from everything else by a well-defined surface so that the interaction between the "system" and everything else may be described by transfer processes across the surface.
Entropy: According to the McGraw Hill Dictionary of Scientific and Technical Terms, entropy is "a function of the state of a thermodynamic system whose change in any differential reversible process is equal to the heat absorbed by the system from its surroundings divided by the absolute temperature of the system. Also known as thermal charge."
Energy: Again from McGraw Hill: "the capacity for doing work." Strictly speaking from a thermodynamics point of view, the McGraw Hill definition is not correct because energy may be classified as thermal energy and all other energy. Thermal energy has the distinction that not all of it is available for doing work. There is a limitation imposed by the Second Law of Thermodynamics. The 2.451 notes spent eight pages defining energy, so further reading is definitely in order.
Property: Any quantity the value of which depends on the state but not the history of the system; for a given state the value of a property can be determined by some type of measurement.
Enthalpy: From McGraw Hill: "The sum of the internal energy of a system plus the product of the system's volume multiplied by the pressure exerted on the system by its surroundings."
Stable equilibrium state: An equilibrium state that can only be altered by interactions that leave net effects in the environment.
Temperature: From McGraw Hill: "A property of an object which determines the direction of heat flow when the object is placed in thermal contact with another object; heat flows from a region of higher temperature to one of lower temperature.
Pressure: From McGraw Hill: "A type of stress which is exerted uniformly in all directions; its measure is the force per unit area."
Available Energy: A property of a system at a state, in reference to an environment of constant temperature and pressure; available energy is the maximum useful work that can be extracted from the combination of the system and the referenced environment.
Other terms in use in the general MIT environment are listed below.
Flush (verb): To reject unequivocally.
Flame (verb): To argue a point of view forcefully.
Cruisillate (cruise + oscillate, verb): To function very fast. Used in describing electronic chips.
Tool (verb): to study very hard; (noun) one who studies very hard.
Power Tool (verb) : to study very hard; (noun) one who studies very hard.
Bogossify (bogus + ossify, verb): To fake, as in results for a laboratory project.
Bogosity (bogus + fugacity, noun): State of being bogus.
Bible (noun): Notebook for a course, 3 to 4 inches thick, including worked-out solution sets to problem sets, lecture notes, and past exams.
Grease (noun): A politically oriented person seeking institutewide student elective office. See embezzler.
Subway Surfing: Riding on the Boston MBTA Red Line, standing up, without holding onto anything.
All-weeker: MIT's version of an all-nighter.
And while definitions are being offered, "Kvel" is Yiddish for a sense of extreme pride, as when a parent sees a child graduate from MIT.
Oil Burning in Closed Room Problem. I was right about the first half of the problem. If the room were perfectly insulated and sealed, there would be no change in energy and no change in mass.
The second part of the question was trickier: "What is the change in mass between the oil-air mixture and the products of combustion if the maximum energy is transferred to the environment?"
They wanted us to invoke Einstein's famous equation: E = mc2. If all the heat of combustion were conducted through the walls of the room, the energy in the room would be reduced by the combustion, and thus the mass of the contents of the room would be reduced.
The problem is first to find the energy of combustion:
So the mass of the contents of the room did decline, by about seven-tenths of a milligram. I lost 3 points out of 50 on the problem set for missing that trick.
CHAPTER 3
The Gasoline and Egg Problem. The problem was to determine how many eggs would be required to feed the human to pump the water, and also to see how muc
h gasoline would be required.
First, calculate the change in potential energy associated with lifting the water up from the bottom of the well.
To find the number of eggs required, we need to convert from kg-calories to joules, and to take into account the 25 percent efficiency of the human prime mover.
Number of eggs required =
The gasoline consumption can be calculated similarly:
The ratio of energy costs in this example is:
The cost of eggs as a fuel is 12.3 times the cost of gasoline. Next, we need to calculate the labor cost of the cyclist. Assuming this is a strong cyclist and can generate about 1/4 horsepower continuously, or about 190 watts, the time required to pump all the water would be:
This cost comes to about $200, at $4 per hour.
Next, calculate the cost of the military might required to secure the oil fields in the Persian Gulf. At an incremental cost of $1 billion per day, plus a cost of, say, $100,000 per life lost, times X lives lost.... Uh-oh. There I go being politically correct again. Shame shame shame shame shame. Of course, if this were written by illuminated manuscript rather than on a personal computer using 200 watts, under three 75 watt lights, with about 300 watts of other lighting on in the office to make me feel secure while working on a Saturday, well then, I might have more of a leg to stand on.
The Three Block Problem. The problem statement was: "Three identical blocks of metal are available. Initially they are at temperatures 300, 500, and 700 K (Kelvin). For each of the blocks, the relation between internal energy and temperature of stable equilibrium states is given by the relation:
"U = Uo + C * T, where C is the heat capacity and T is the temperature in degrees Kelvin. Let's say C = 10 joule/Degree K (the answer is independent of C).
"If interactions via cyclic machinery between blocks are allowed but interactions between the blocks and the environment are not, what is the maximum temperature that can be reached by one of the blocks?"