Q3. [15 marks] A solid steel shaft (E = 210 GPa, ? = 0.33) of radius 20 mm has been forced into an aluminium gear (E = 70 GPa, ? = 0.33) of outer radius 40 mm and thickness of 10 mm. There is a radial interference of ? = 0.02 mm. a) Determine the contact (interface) pressure, pc ; [6 marks] b) Sketch the radial stress distribution in the shaft and the gear; [5 marks] c) If the coefficient of friction between the shaft and gear is μ = 0.1, what axial force would be required to move the gear along the shaft? [2 marks] d) What is the maximum torque, which can be transmitted through the shaft? [2 marks] If you cannot solve a) and b) for c) and d) assume pc = 100 MPa.

Issue # 2 - A V-belt from a 10 in. Diameter spindle pulley that rotates at 1800 rpm, to a 36 in. Diameter flat pulley. The wheelbase is 40 "and the throat angle is 40o. The friction coefficient between the belt and the grooved pulley is 0.2 and with the flat pulley it is also 0.2. The cross section of the straps is a trapezoid with parallel sides of 1.5 "and 0.75", with a height between them of 1 ". The weight of this belt is 0.04 lbf / in3, and the maximum allowable tension on each belt is 200 lbf. Determine: a) How many straps are needed. b) The Torque applied in the transmission, c) The Transmitted power. Note: Consider locating the center of gravity of the belt cross section in order to correct the actual pulley diameter as the band on the splined pulley is slightly outward.)

Describe the principle of operation of both the positive displacement and roto-
dynamic pumps.

b) List three (3) characteristics each of the above pumps .

c) Sketch a gear pump and label it.

You are required to design and fabricate a composite material to be used for machining hard steels. Use the information presented in your lecture notes and:

i) Identify the type of a composite that you would like to design, then select the appropriate reinforcement and matrix and fully justify your selection.

ii) Select a fabrication route for the designed composite and justify your fabrication process selection with respect to temperature and time

s) Sketch a rotary vane steering gear, label the parts and explain how it functions.

b) List five (5) vital checks to carry out prior to the ship sailing out of port.

c) Draw a basic direct expansion refrigeration cycle and describe its operation

d) In Heating Ventilation and Air Conditioning (HVAC), explain what operation is carried
out to achieve comfort (in terms of humidity) during summer and in winter.

As a manufacturing engineer, you are required to decide on the machine tool and cooling liquid for a stainless steel automotive part. Aided with a block diagram of a machine tool, briefly explain the overview of the machining process including the justification of your parameter selections

A supply line carries a two-phase liquid-vapor mixture of steam at 20 bars, state 1. A small fraction of the flow in the line is diverted through a throttling calorimeter and exhausted to the atmosphere at 100 kPa. The temperature of the exhaust steam, state 2 is measured as 373 K. Determine (a) the quality at the exit in %

Two aeroplanes with the same specification each that has an engine rotates at 2000 rpm with the moment of inertia for all rotating parts is 420 (kg)(m^2). The engine rotates anti-clockwise when viewed from the front. One of the aeroplanes turn to the left and the other turn to the right. Compare the magnitude and effect of the gyroscopic action resulting on the plane if the turning radius is 2000 m at a speed of 2000 km/h.

You have been appointed the project manager of a big project on account of your prior experience of many years in the same field. Your team comprises a mix of experienced and fresh engineers. Explain how you would go about estimating the times and costs, the methods you would choose and the reasons for your choices.

1. The net weight (in oz.) of a dry bleach product is to be monitored by X and R and X and S control charts using a sample size of n = 5. Data for 20 preliminary samples are shown below.

Determine the trial central line and control limits for the X and R (24 points).

UCLX=

CLX=

LCLX=

UCLR=

CLR=

LCLR=

Determine the trial central line and control limits for the X and S (24 points).

UCLX=

CLX=

LCLX=

UCLS=

CLS=

LCLS=

) Consider a 1.5-m-high and 3-m-wide glass window whose thickness is 6 mm and thermal conductivity is k = 0.88 W/m · °C. Determine the steady rate of heat transfer through this glass window and the temperature of its inner surface for a day during which the room is maintained at 27°C while the temperature of the outdoors is -7°C. Take the convection heat transfer coefficients on the inner and outer surfaces of the window to be h₁= 11 W/m² · °C and h₂ =26 W/m² · °C, and disregard any heat transfer by radiation

A thin aluminum sheet with an emissivity of 0.25 on both sides is placed between two very large parallel plates, which are maintained at uniform temperatures T1 = 600◦C and T2 = 325◦C and have emissivities ε1 = 0.5 and ε2 = 0.8, respectively. Determine the net rate of radiation heat transfer between the two plates, per unit surface area of the plates,

(a) without the radiation shield, and

(b) with the radiation shield. What is the percentage reduction in heat transfer with the shield?

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

A flat metal belt, made of Beryllium-Copper (BeCu), is Sf = 375 MPa and transmits at 8,84 rpm and 8.25 kW of power. The distance between the two spindle axes on the same horizontal plane is 935 mm and belt life is 10⁶ turns. The friction coefficient between the belt and the pulley will be 0.34, the operating coefficient is 1.41, and the design coefficient will be 1.55. The diameter of the translated pulley is 3.25 times the diameter of the motor pulley. The belt thickness is 0.20 mm and in case of using a minimum diameter pulley, calculate the belt width and length. The belt width should be 5 mm and its multiples. Calculate the pretension force to be applied