The flowrate for water traveling through a horizontal 300 m-long cast iron pipe with a diameter of 0.6 m and a pressure drop of 17.2 kPa is to be found. P.S. use iterative approach to find values of f and then V using that f.

In a gas turbine of a thermoelectric plant a regenerator is used that preheats the air before it enters the combustion chamber. You have the options of a backflow heat exchanger or a shell heat exchanger and two tube passages. The air leaves the compressor at a temperature of 350 C and the exhaust gases have a temperature of 700 C. The mass flow in both cases is 5 kg / sec. The overall transfer coefficient is 75 w / m2 K. In both cases the area is 18 m2. Find the best posible exchanger.

The paper rolls, shown in the figure below, are 0.9 m OD x 0.22 m ID x 3.23 m long and have a density of 984 kg/m3 . The rolls are transferred from the machine conveyor (not shown) to the forklift truck by the V-linkage of the off-loading system, which isrotated through 90o by an air cylinder. The paper then rolls onto the waiting forks of the truck.

Question: Assume that the crank arm is a solid rectangularsection. Working on a factor ofsafety of 5, determine suitable dimensions for this arm. Select (providing reasons) a material for this crank arm. b) Due the misalignment of the loading (refer 2c), the force is offset from the loading axis by 15o . Determine the bending stresses at each of the four corners of the arm cross section. Also determine the position of the neutral axis. Illustrate the stress distribution and neutral axis on a sketch of the section.

Ethane (C₂H₆) is burned with air in a steady-flow combustor. The mass flow rate of fuel entering the combustor is 0.57 kg/s and the equivalence ratio is 0.64. The fuel enters at 25^oC and the air enters at 500 K. Determine:

The heat release rate, in kW.

The mass flow rate of air, in kg/s.

The mole fraction of O₂ in the products.

The mass fraction of CO₂ in the products.

The total mass of CO₂ produced per year (365 days), assuming that they system operates continuously 24 hours per day, in kg.

The adiabatic flame temperature, using 1400 and 2400 K as your guesses.

Ethane gas (C₂H₆) is burned with air. The fuel flow rate is 0.1 kg/s and the air flowrate is 2.2 kg/s. Ethane’s enthalpy of formation is -84,680 kJ/kmol. Determine:

The equivalence ratio

Ethane’s lower heating value by deriving it from enthalpy of formation data.

The heat release rate, in kW.

The mass fraction of oxygen in the products.

The mass of CO2 emitted per 1000 hours of operation.

The mass of fuel burned per 1000 hours of operation.

The adiabatic flame temperature, using 1400 and 2200 K as your guesses.

Q2 Write short notes on any two of the following:

a) Optimum Design. b) New Design c) Empirical Design [12 marks]

(iii) Mention two methods used in design in minimizing stress concentration. [5 marks]

Q4 (i) Find the power transmitted by a 50mm diameter solid shaft running at 200rpm if the shear strength of the material is 124 MN/m2 using factor of safety of 2.

What will be the power transmitted by an equivalent hollow shaft of the same cross sectional area as the solid shaft above, if the ratio of the outside to inside diameter is 3/2. [18 marks]

(ii) Explain the meaning of the answers in (i) above

Explain how tacticity (isotactic, atatic) effect the molecules crystalinnity and other characterstics.

Question 3 a)In an Electrochemical Machining process, the feedstock is made of an aluminium alloy (Ultimate Tensile Strength=572 MPa, Tensile Yield Strength=503 MPa). The desired time to machine a hole (?=10 mm) through a 20 mm-thick part is 2.1 min at a feed rate of 0.18 mm/s. What are: (i)the efficiency of the process in %, and (ii)the current requirement in amps to achieve this machining time target? [30 marks] Describe in detail the process of circular sawing with the aid of a freehand sketch. What are the two major mechanisms by which circular sawing is achieved and what materials are commonly used as circular saws of each type?

Briefly explain the following terms:
a)Exiting phenomena(drilling)
b)Sparkling out process(grinding)
c)Six point rules

1045 Steel (quenched specimen)

Draw a picture of what you think the microstructure would look like and label the constituents (martensite, ferrite, cementite or whatever you expect to find in this quenched specimen). Include the figure number.

Capillary number is proportional to { (viscous force) / (surface tension force) } and is used in momentum transfer in general and atomization and 2-phase flow in beds of solids calculations in particular. It is equivalent to (We/Re).

___________ Which is the friction factor for ReD = 600 and e/D = 0.002 in pipe flow?

___________ What is the friction factor for ReD= 3 x 105 and D/e = 5000 in pipe flow?

Iron ores found in Ireland and Britain are not suitable for production of high-quality steel because they contain too much of which one of the following elements:

(a) Sulphur
(b) Carbon
(c) Nitrogen
(d) Phosphorus?

The inside of the stack of a blast furnace is usually lined with:

(a) Steel sheets
(b) Ceramic refractories (c) Asbestos
(d) Water-cooled copper?

To improve the fuel-efficiency of the modern blast furnace, which one of the following may be added to the blast:

(a) O2 (b) N2 (c) H2 (d) CO2?

In steelmaking, basic slags are necessary for the removal of which element:

(a) Carbon
(b) Silicon
(c) Phosphorus (d) Oxygen?

Give three examples of materials properties, and indicate where they are used in engineering product development. Compare any one of the listed properties for Metals, Ceramics, and Polymers materials on the same scale graphically

A circumferential aluminum fin is attached to an electronic resistor having 1/4 inch diameter. The fin is 1/8 inch long and .001 inches thick. The convective heat transfer coefficient to the surrounding media, air at 60^oF, is 10 Btu/h ft^{2 o}F when the fin is at 120^oF. Estimate the fin efficiency and the heat transfer from the fin.