Why do materials fail at lower loads if stress is cyclic? Describe fatigue mechanisms for alloys with pre-cracked structures.

FIreclay brick (ρ=2050 kg/m3, cp=960 J/kg-K, k=1.1 W/m-K) with dimensions 0.06 m x 0.09 m x 0.20 m is removed from a kiln at 1600K and cooled in air at 40C with h = 30 W/m2-K. What is the temperature at the corner of the brick after 50 minutes of cooling? Give your answer in degrees C.

a simple ideal Brayton cycle with air as the working fluid has a pressure ratio of 10. The air enters the compressor at 520 R and the turbine at 2000 R. Accounting for the variation of specific heats with temperature, determine (a) the ait temperature at the compressor exit, (b) the back work ratio, and (c) the thermal efficiency.

What is the General Equation? Explain the variables and parts of the equation. How is the GEneral Energy Equation applies to Water PUmps?

Define the system, control volume, and control surface for a 4-foot, 6-inch diameter section of pipe. Is the system Lagrangian or Eulerian? Why?

Case “EXCESS”

     Stephanie Simon knew environmental manager Adam Baines would not be pleased with her report on the chemical spill. The data clearly indicated that the spill was large enough that regulations required it to be reported to the state. Stephanie perceived Adam to be someone who thinks industry is overregulated, especially in the environmental area. At the same time, he prided himself as a major player in maintaining LPC Chemical’s public reputation as an environmental leader in the chemical industry. “We do a terrific job,” he often said. “And we don’t need a bunch of hard to read, difficult to interpret, easily misunderstood state regulations to do it. We got along just fine before the regulators ran wild, and we’re doing fine now”

     When Stephanie presents her report to Adam, he loses his temper. “This is ridiculous! We’re not going to send anything like this to the state. A few gallons over the limit isn’t worth the time it’s going to take to fill out those damned forms. I can’t believe you’d submit a report like this. Stephanie, go back to your desk and rework those numbers until it comes out right. I don’t want to see any more garbage like this.”

     Stephanie refuses to rework the report. Instead she goes back to her desk, signs the report, writes a memo about her conversation with Adam, and then returns to Adam’s office. She hands him the report and says, “You don’t want to see any more garbage like this? Neither do I. Here’s my original report – signed, sealed, and delivered. I’ve had it here. I’m not fudging data for anyone. As she turns to leave, she adds, “By the way, Adam, before you get any ideas about making it hard for me to get another job, I have a nice little memo about our earlier conversation. I won’t hesitate to send it right upstairs at the slightest provocation.”

disobedience (by contrary action, by nonparticipation, by protest),

Describe these 3 different types of organizational disobedience. In what type of disobedience did Stephanie engage?. Do you think she handled the problem in the best way? If not, how should she have handled it? Why?

Top fuel dragsters (right) as the quickest accelerating cars in the world, and the fastest competitors reach speeds of 335mph, completing a 1000ft run in just 3.64s. The 0 to 100mph time during these runs is as little as 0.8 seconds. The 4-stroke engine geometry used in these dragsters can be seen in Table 1. These engines run on nearly pure nitromethane (properties in Table 2).

Table1: Top Fuel Engine Geometry

Table2: Nitromethane Properties

A) (10pts) Calculate the BMEP in [bar] produced by a top fuel dragster at peak power.

(Answer: BMEP = 136.6bar)

B) (25pts) A top fuel dragster consumes about 11.2 gal/s of nitromethane at full throttle, and operates at an equivalence ratio, ϕ, of 5.0. Determine the air flow and fuel flow per cylinder at full throttle in [kg/s] (1gal = 3.785L). (Answer: ṁ_fuel= 6.04 kg/s per cylinder, ṁ_air= 2.052 kg/s per cylinder)

C) (15pts) Determine the brake fuel conversion efficiency of a top fuel engine operating at peak power. (Answer: η_f= 1.38%)

Describe conditions for a self-sustaining plasma

A flying wing has a planform area of 3700 ft², a root chord at the airplane centerline of 34 ft, an overall taper ratio of 0.275, and a span of 170 ft. The average weighted airfoil thickness ratio is 10.2% and the wing has 36 degrees of sweepback at the 25% chordline. The air- plane is cruising at a pressure altitude of 17,000 ft on a standard day with a wing loading of 40 lb/ft². The cruise Mach number is 0.30. Determine the following:

(a) skin-friction drag coefficient (assume a spray-painted surface)

(b) pressure drag coefficient

(c) induced drag coefficient

(d) total drag coefficient

(e) total drag in pounds

Remember that a wing has both upper and lower surfaces exposed to the flow. Use the appropriate skin friction coefficient equation (Chp 4) that would include transition from laminar to turbulent; assume Re,trans = 500,000. If the surface is fully-rough, then consult 5.20 on pg 266. Form drag is based on the fineness ratio charts. The Oswald efficiency factor is high for wings—assume e = 0.95.

Describe the issues of thin film stresses.

A new material has a measured thermal conductivity k of 200 BTU-in/hr-ft2 -°F. Is this material a thermal insulator or a conductor? Calculate the R and U values for a block of this material that is 3 inches thick. Now sandwich this block of material between two sheets of R-0.8 fiberboard. What is the new effective U value?

9.43 An ideal air-standard
state with compressor inlet conditions of 300 K and 100 kPa and a fixed turbine inlet temperature of 1700 K. For the cycle,

Plot the net work developed per unit mass flowing, in kJ/kg, and the thermal efficiency, each versus compressor pressure ratio ranging from 2 to 50.

I need the IT Thermodynamics software code, or at least I need to know how to set the code up. Also, please note that this is an air-standard cycle.