Q5. State whether the following are true or false with brief justifications:

(i) The maximum thermal efficiency for any power cycle operating between two thermal reservoirs at temperatures T1 and T2 (T1 > T2) is 1- T2/T1.
(ii) Transferring heat from a cold object to a hot object is forbidden according to the Clausius statement of the second law.

(iii) A cycle that does not violate the Kelvin-Planck statement cannot violate the Clausius statement of the second law.
(iv) For a reversible power cycle, if we hold the temperature of the cold reservoir (TC) constant, we can increase the thermal efficiency ? to any value smaller than 1 (100%) by varying TH.

(v) A system interacting with air at different heights in the atmosphere is interacting with only one thermal reservoir, i.e., the atmosphere.

What A laminated steel (E = 200 GPa and ? = 0.3) cylinder consists of a jacket with an inside diameter of 200 mm and an outside diameter of 300 mm shrunk onto a tube with an inside diameter of 100 mm. The initial shrinkage pressure is 25 MPa.
Determine:

a. The maximum tensile stress in the cylinder after it is fabricated subject to an internal pressure of 200 MPa.

b. What and where is the maximum shear stress?

Describe how the capabilities of humans versus machines drive the allocation of functions in human-centered design. Provide examples.

A mixture of 92 kg of ZrO2 with 8 kg of CaO is melted into a liquid at high temperature

. a) On slow cooling, at what temperature will solid first appear?

b) What is the composition of this solid?

c) At what temperature will the sample become completely solid?

c) As the sample continues to cool, at what temperature will a second solid phase begin to precipitate?

d) What is the composition of this solid phase?

e) What is the expected composition and relative amounts of the phases expected to be present at room temperature?

1- write Commissioning, Startup, Operation, and Shutdown procedure of a pump

2- What is the function of shaft sleeve for a centrifugal pump?

3: Discuss the types of pipe reducers for a centrifugal pumping system

4: Write a gate valve mounting procedure

5: Write assembly and dismantling procedure of a rising stem gate valve

compare these machines in terms of cost and specify the reasons: extrusion machine, injection molding, and hot press machine

Boiler produces 250,000 pounds of steam per hour at 1200 psia and 1050 degrees Fahrenheit from feed water entering the boiler at 1500 psia and 300 degrees Fahrenheit. Fuel oil having a higher heating value of 18,000 Btu/lb is supplied to the burners at a rate of 20,500 lb/hr. Furnace volume is 1,500 cubic feet.

Calculate:

a) boiler capacity

b) factor of evaporation

c) equivalent evaporation

d) furnace heat release rate in Btu/hr ft^3

e) boiler efficiency

A symmetrical wedge having a total vertex angle of 60 degrees is traveling at a Mach number of 3 at an altitude of 15 km. What are the static values of the pressure, density, and temperature downstream of the shock, and what are the stagnation values of those quantities? What is the percentage loss of the stagnation pressure across the shock wave?

1. Identify four new materials in modern automotive industries that were introduced in the last twenty years or so that were not used before. Specify the parts made of these materials. 2. Briefly describe the compositions of the above mentioned materials/parts (Four materials)

3. Briefly mention how these (four) materials/parts are being made 4. Briefly describe how effective the above mentioned materials are in fulfilling the needs and improving the performance.

How does “surface roughness” affect the “fatigue stress endurance limit?

What is the effect of pre-setting on stresses during loading of helical compression springs?

Discuss elevated temperature effects on loading of helical compression springs

1) In regards to the cross-sections of straight members, what two axes coincide?

2) Give the two equations known as the curved-beam formula. Define each variable.

3) As discussed in class, what is the theory of failure for ductile materials?

4) As discussed in class, what is the theory of failure for brittle materials?

5) What is the most common mechanism of yielding of a ductile material, such as steel?

6) The yield stress for a zirconium-magnesium alloy is ?Y = 15.3 ksi. If a machine part is made of this material and a critical point in the material is subjected to in-plane principal stresses ?1 and ?2 = -0.5?1, determine the magnitude of ?1 that will cause yielding according to the maximum shear stress theory.

Identify the kind of chips – continuous, discontinuous, segmented or built-up edge, that the following workpieces will tend to form under typical cutting (turning) conditions (i.e. not severely high cutting speeds, depths of cut or feeds). Also, state the reason for why that would be the case.

a) Grey Cast Iron

b) Titanium

c) 4140 Alloy steel

d) stainless steel 316

Moist air at 30 °C and 50% relative humidity enters a dehumidifier operating at steady state with a mass flow rate of 319.35 kg/min. The moist air passes over a cooling coil and water vapor condenses. Condensate (condensed water) exits at 10 °C. Saturated moist air exits in a separate stream at the same temperature. The pressure remains constant at 1 bar. Determine (a) the rate at which water is condensed, in kg/min, and (b) the heat transfer rate during the cooling, in kW

Saturated liquid Propane flows in to a valve. It enters at 375 psia, and leaves at 15 psia. Mass flow through the valve is 1.25 lbm/hr. Use EES and ‘Propane’ as your fluid.  This new device replaces the valve with a ‘magic’ isentropic device. Assuming the device operates at steady state, and PE and KE terms are insignificant, calculate how much power could be generated by the device (hp)?

In an ideal Rankine cycle with reheat, superheated steam vapor enters the turbine at 10 MPa and
480 °C, while the condenser pressure is 6 kPa. Steam expands through the first-stage turbine to
0.7 MPa and then is reheated to 480 °C
a) For a pressure of 7 bar right after the first stage turbine in the ideal Rankine cycle, create
two plots: thermal efficiency as a function of the reheat temperature from 200 °C to
500 °C; and the net work, heat addition, and heat extraction on the same graph as a
function of the reheat temperature from 200 °C to 500 °C