1. Itemize 6 ways in which defect control can be used to our advantage in engineering designs. Include specific examples.

Question 1) In an air standard diesel cycle, the conditions of the air at the start of the compression stroke are 2 bar and 30℃. The pressure rises to 30bar after compression, and through combustion, 1200 kJ of energy is added per kg air. Calculate

1. Compression ratio
2. Cutoff ratio
3. Mean effective pressure
4. Temperature and pressure at the end of each process
5. work done per kg air
6. Thermal efficiency of the cycle

Which of the following modifications would REDUCE the likelihood of cavitation in a pump and piping system?

a) raising the pump

b) increasing the flow rate

c) lowering the position of the pump in the system

d) raising the temperature of the pumped fluid

e) lowering the inlet piping to the pump, while keeping the pump in the same position

TRUE OR FALSE? In pipe flow, if the Reynolds number is very large, then the friction factor depends only on the non dimensional pipe roughness.

The drag force on a large ball that weighs 200 g in free flight is given by FD = 2*10 V , where FD is in Newtons and V is in meters per second. If the ball is dropped from rest 300 m above the ground, determine the speed at which it hits the ground. What percentage of the terminal speed is the result?

An ideal vapor-compression refrigeration cycle is modified to include a counterflow heat exchanger, as shown in the figure below. Ammonia leaves the evaporator as saturated vapor at 1 bar and is heated at constant pressure to 5°C before entering the compressor. Following isentropic compression to 18 bar, the refrigerant passes through the condenser, exiting at 40°C, 18 bar. The liquid then passes through the heat exchanger, entering the expansion valve at 18 bar.

If the mass flow rate of refrigerant is 16 kg/min, determine:

(a) the refrigeration capacity, in tons of refrigeration.

(b) the compressor power input, in kW.

(c) the coefficient of performance.

(d) the rate of entropy production in the compressor, in kW/K.

(e) the rate of exergy destruction in the compressor, in kW.

Let T₀ = 20°C

A vapor-compression refrigeration system for a household refrigerator has a refrigerating capacity of 1650 Btu/h. Refrigerant enters the evaporator at -15°F and exits at 20°F. The isentropic compressor efficiency is 75%. The refrigerant condenses at 125°F and exits the condenser subcooled at 100°F. There are no significant pressure drops in the flows through the evaporator and condenser.


For Refrigerant 134a as the working fluid, determine:

(a) the evaporator and condenser pressures, each in lbf/in.²

(b) the mass flow rate of refrigerant, in lb/min.

(c) the compressor power input, in horsepower.

(d) the coefficient of performance.

The seniors at Weseltown High School are voting on where to go for their senior trip. They are deciding on Angel Falls(A), Bend Canyon(B), Cedar Lake(C) or Danger Gap(D). The results of the preferences are:

DABC = 120

ACBD = 100

BCAD = 90

CBDA = 80

CBAD = 45

a. Who is the Condorcet candidate?

b. Is there a majority winner? If not, is there a plurality winner? Does this violate the Condorcet criterion?

c. Who wins the Borda count? Does this violate the Condorcet criterion?

d. Who wins using the Hare method? Does this violate the Condorcet criterion?

e. Who wins using the pairwise comparison method? Does this violate the Condorcet criterion?

develop a programming code in FORTRAN 77 software for solar assisted air source water heat pump inline connected with bry air dehumidifier and pulse tube cryocooler

value of y is _____4_______.

Consider an ideal vapor-compression refrigeration cycle using Freon 410A (see . https://www.freon.com/en-/media/files/freon/freon-410a-si-thermodynamic-properties.pdf) The pressure in the evaporator is 10y kPa (That is, if y = 3 the evaporator pressure is 30 kPa). and the temperature at the exit of the condenser is 40^oC. The mass flow in the system is (0.05 + y/200) kg/s.   (That is, if y =3, then the mass flow is 0.0.065 kg/s).

1. Find the enthalpy at the entrance to the compressor.                    h = __________ kJ/kg (+ 3 kJ/kg)

2. Find the enthalpy at the exit of the compressor.                              h = __________ kJ/kg (+ 5kJ/kg)

3. Find the enthalpy at the exit of the condenser.                                h = __________ kJ/kg (+ 3kJ/kg)

4. Find the rate of heat transfer in the evaporator:                              = __________ W (+ 300W)

21. Make a comparison of welding, adhesive joining, and mechanical fastening in regard to bond strength and service temperature limitations.
22. List four basic types of fusion welds, and draw sketches.
23. Lis any three defects associated with fusion welding, and describe them briefly.
24. Draw a sketch of weld section, and label three zones; namely: base metal, weld metal and heat affected zone.
25. Define power density and include its units, and describe how power density affects size of heat affected zone?
26. Sketch Fe-Fe3C equilibrium phase diagram, and identify the following:
a. Alpha region
b. Gamma region
c. Delta region
d. Eutectic point
e. Eutectoid point
f. Lower critical temperature line, A1

27. Identify the methods that can be employed to minimize the distortion in the welded workpieces.
28. Identify one high power density and one low power density welding process.
29. Sketch a fillet weld, and identify weld size, throat size and convexity or concavity?
30. Two AISI1020 Steel plates 6 mm thick each are to be welded through a T-Joint double fillet weld using
SMAW process. Assume that each leg of the fillet weld is equal to 4 mm, and the weld has a flat face.
Perform the tasks:
a. How much metal in grams will be required to make the welds? Density of steel weld metal is 7.85
g/cm3.
b. How many electrodes will be required to make the weld if diameter of the electrode is 4 mm, and
length is 350 mm? Assume that electrode metal deposition efficiency is 65%.

explaining heat transfer fets; for cartesian coordinates
a) in continuous regime
b) in a continuous regime and in the absence of heat production
c) in the continuous regime, in the absence of heat production and one-dimensional (in the x direction)
Obtain the general heat equation.

Right now you live in a house that is pretty old and doesn’t have double- paned windows. Your heating bill in the winter and spring will be really big, and you think it might be due to the huge single-paned window in the living room. Your landlord has told you that he is willing to replace it with a double paned window but you have to cover the cost of the window. You want to do a quick calculation to see if you can recover the cost of the new window before you graduate (and hopefully move out). If electricity used for heating costs 6.90 cents per kWh, will you save enough money? Assume 120 days of winter, followed by 90 days of spring until your graduation.

The living room is 3.5 m by 4.2 m, and is 2.4 m tall. The exterior wall has the standard 20 cm of fiberglass insulation. The existing window is on the narrower wall at one end of the living room and is 130 cm wide, 75 cm tall, and 4 mm thick. The new window is a state-of-the-art double paned window, with two panels of 4 mm glass separated by a 2 mm air-filled gap. Use the following values of thermal conductivity:
kfiberglass=0.04 W m−1 K−1, kglass=0.96 W m−1 K−1, kair=0.024 W m−1 K−1.

And also assume the following values for the average temperature:

Thouse=20∘C inside the house (to be maintained)

Twinter=3∘C outside the house during winter

Tspring=8∘C outside the house during spring

Finally, you estimate that the house is heated for 12 hours per day on average.

1.Calculate the heat conduction rate of the single-paned window during spring and winter.

2. With multiple layers of material with separate thickness and thermal conductivity values, the heat conduction rate must be calculated using the total resistance R.

Using the description of the double pane window, calculate its total resistance R. Give your answer in W−1 m2 K, to four decimal places.

3. Calculate the heat conduction rate of the double pane window during spring and winter.

4.calculate the total energy saved during spring and winter by switching to the double pane window in kwh

5. Using the answers above, calculate the total savings in the heating bill. Assume that the efficiency of converting electrical energy to heat is 100%. Give your answer in dollars.

A Four bar mechanism with a frame length of 200 mm, crank length of 100 mm, coupler length of 300 mm and follower length of 250 mm, if the mechanism is assembled in open cpen configuration and the input angle is 45^{o .}

what is:

1-The coupler angle for open and crossed  configuration ?

2-The output angle for open and crossed configuration ?