Recap of last week
Frame Group used primer on the gas tank and wheel fenders
Model T: Wheel brake can be adjusted to half or fully loosened. When full, a spring puts the leftmost pedal automatically at high gear.
Recap of Prof. Ju’s visit:
-Relationship can be established between temperature chance and work done (Thermodynamics)
-The higher the compression and larger the volume of the combustion chamber, the larger the decrease in temperature as a piston moves down and the gas expands, and therefore higher efficiency.
v = sqrt(3kT/m)
Thermodynamic Efficiency = (kTH – kTc) / kTH
-We learned the difference of leaded and unleaded fuels, and the different numbers for different fuels. The higher the number, the higher the octane number. Lead, alcohol and other additives used to react with the smaller hydrocarbons, so that only larger, less reactive ones remained.
-Diesel engines use self-ignition
-Significance of nitrus: Higher oxygen percentage than in air (21%).
-Compression ratios, bad side: Harder to start, higher emissions, higher pressures. Require stronger materials as stress on materials stronger.
Hybrids- Two different types of hybrids. Volt vs Prius. Volt uses a battery first and then the gasoline engine after battery runs out. This means that both the battery/electrical drive system and the gas engine must be high quality. On the Prius the gasoline engine charges the battery, so the batteries don’t necessarily have to be as good.
Modern fuel injection reduces knocking as the fuel is not drawn in on the compression stroke, but rather can be controlled and timed to come in at the right time.
Turbo/Superchargers – Compresses the air that comes into the combustion chamber, so that it’s higher pressure and preheated. Turbocharger uses exhaust gases to drive the compression.
Questions for Prof. Martinelli
Computational Fluid Mechanics. Boeing Fellow.
-Drafting. Slipstream.
-How close the front of the car is to the ground.
-Downforces. Rear wings. How it can improve traction on the rear wheels.
-How fast can a car go?
-Boundary layer for aerodynamics.
-Solar powered airplane
-Jets on a carburetor. At high altitude the engine runs lean because of not enough air. So what do you do with the jets? By opening them up?
-Venturi?
-Driver positions for drag? Drag on on a motorcycle. How to reduce it?
-Fins on the motorcycle. How many? How big? How you figure out the fin configuration.
The Art and Zen of Motorcycle Design
Chapter 12/13:
-His relationship with DeWeese: They are very different in the way they approach things. E.g. DeWeese not understanding his sense of humor. This is why Phaedrus is fond of DeWeese though, because they have different thoughts. (Karen) Often irritated with each other however. (Danny) Are fascinated with each other because they don’t understand each other(Shirley).
-Phaedrus giving up his dedication to reason. The idea of not presuming that if something is logical, that it has to be the truth (Margaret).
-Classical vs Romantic inquiry in Oriental Philosophy. He’s come to doubt means of inquiry. (Frances)
-The “Church of Reason”. (Jenny) He is fanatical about what he does. He gets fed up with the Oriental Philosophy and contradicts himself. He is very keen on the idea of the University being both a set of subjects (what is being done) and a set of objects (buildings, etc). (Danny)
-He doesn’t understand Oriental Philosophy and is extremely contradictory of himself. (Littman) He doesn’t quite respect it for what it is (Dan).
-The primary goal at a “Church of Reason” should always be truth. Too often it becomes more bureaucratic or entangled with other priorities and issues. (Jenny)
-You’re never dedicated to anything that you have complete confidence in. (Littman)
Chapter 14
-The Instruction Manual: Even though the machine might work fine, if you’re not in the right state of mind, then the machine might not do what it’s supposed to do.
-Someone who has experience and knows what they’re doing adapts as they go along instead of just blindly following instructions.
-The difference between art and science; Science is to break down, and art is to put together. To look at someone as the pieces or to look at the pieces as a whole, and the different meanings that it takes on as a result.
-Connection back to Kant. Looking at a bunch of parts with just your senses versus looking at them with knowledge, you are much more oriented and see it as a motorcycle.
-Difference between art and technology. The divorce of art from technology is completely unnatural.
-It’s often better when technology is combined with art. Both are required to achieve something both functional and aesthetically pleasing.
-The idea that science works with chunks and bits with continuity presumed. DeWeese works with continuity with chunks and bits presumed.
NO READING
For Next Tuesday: Chapter 15 of Zen.
For Next Thursday: Next Chapter of Soulcraft (Chapter 6).
Brake Dynamometer
Measuring the torque speed curve for an electric motor.
Using a rope brake.
You can figure out the torque that a motor can produce, and the power it can produce, and make a measurement as a function of speed.
Pulley 2 inches in diameter. A rope going over a spinning wheel. The torque on the wheel is equal to (T1-T2)/r
Torque-speed relationship is linear.
Power = Fv
So the Power curve is a parabola.
1 HP = 33,000 ft-lb/min
For an electric motor, the maximum power delivered to a load is at half the no-load speed.
For humans there’s a hill curve. The maximum efficiency is around one revolution per second.