1. List and discuss the basic things you must do to a machine in the morning when you are

    about to start operating the machine and when you also close the day’s work.

2. Discuss ten (10) characteristics of a well –organised workshop

3. Discuss the strategies you will adopt to give the newly employed staff to be careful in the workshop.

The rectangular hollow section in this welded assembly has a height of h=73mm, a width of w=48mm and a length L=592mm. For the weld in this assembly, calculate either the Unit second polar moment of Area or the Unit Second Moment of Area, whichever is required to determine the secondary shear stress for this weld loading condition. Provide your answer in m³.

What is Hertz's theory of contact about roller bearing?

1) Determine unmodified fatigue strength (units = MPa) of hot-rolled 1030 steel shaft in axial loading for a design life of 10,000 cycles. Do not apply any fatigue correction factors. SN __________ MPa

2) Determine unmodified fatigue strength (units = ksi) for a normalized 4130 steel shaft in bending for a design life of 10^7 cycles. Do not apply any fatigue correction factors. SN __________ ksi

3) Determine unmodified fatigue strength (units = MPa) for cold-rolled 3003 aluminum rod in torsion for a design life of 10^8 cycles. Do not apply any fatigue correction factors. SN __________ MPa

4) Determine fatigue correction factors for the 0.43 inch DIA shaft from H04 using 4340 steel (quenched and tempered at 800° F). The surface of the shaft was machined but was not ground. The shaft is in bending and torsion, operates in normal environmental temperatures and should have 99.9% reliability. Cload _________ Csize _________ Csurf _________ Ctemp _________ Creliab _________

5) Determine modified fatigue strength (units = ksi) of for the steel shaft from H04 and problem 4) above for a design life of 10^9 cycles. SN __________ ksi

Describe the meaning of availability?

Prob.3) A jet-powered aircraft flies at a speed of 320 m / s at an altitude of 9150 m, where the ambient conditions are 32 kPa and –32 ° C. The pressure ratio in the compressor is 12 and the temperature at the inlet of the turbine is 1,400 K. The air enters the compressor at a rate of 60 kg / s and the jet fuel has a calorific value of 42,700 kJ / kg. Assuming ideal operation for all constant specific components and heats for air at room temperature, draw the diagrams and determine:

a) the velocity of the exhaust gases,

b) the developed propulsion power, and

c) the propulsion efficiency and the fuel consumption rate.

Prob. 2) A jet powered aircraft flies at a speed of 900 ft / s at an altitude of 20,000 ft, where the ambient conditions are 7 psia and 10 ° F. The pressure ratio in the compressor is 13 and the temperature at the inlet of the turbine is 2400 R. Assuming an ideal operation for all specific components and heats
constants for air at room temperature draw and graph the physical and T-S diagrams and determine:

a) the pressure at the outlet of the turbine and the thrust

b) the speed of the exhaust gases and

c) the propulsion efficiency.

Predicting Trends in Engine Performance

a) Write an expression for bmep in terms of the thermal efficiency, mechanical efficiency, volumetric efficiency, and combustion efficiency, as well as other engine design parameters. Group terms together that are related to engine thermochemistry, engine fluid mechanics, and engine kinematics/machine design. Identify each of these groupings.

b) Write an expression for the brake specific fuel consumption in terms of the mechanical efficiency, thermal efficiency, and combustion efficiency as well as the heating value of the fuel.

c) Reasoning with your equations, indicate the sign (+, -, or 0) of the likely change in bmep and also in bsfc based on modification of the design or operating parameter. Assume that all other design/operating conditions remain the same. Provide a short rationale for each answer.

- Increasing ambient temperature

- Decreasing ambient pressure

- Increasing engine displacement

- Increasing the air/fuel ratio

- Using a lower viscosity lubricant

- Improving intake/exhaust tuning

Prob.1) Consider a combined gas and steam power plant that has a net power output of 450 MW. The pressure ratio of the gas turbine cycle is 14. Air enters the compressor at 300 K and the turbine at 1 400 K. The combustion gases leaving the gas turbine are used to heat the steam to 8 MPa. up to 400 ° C in a heat exchanger. The combustion gases exit the heat exchanger at 460 K. An open feedwater heater is incorporated into the steam cycle operating at a pressure of 0.6 MPa. The condenser pressure is 20 kPa. Assuming that all compression and expansion processes are isentropic, graph the physical and T-S diagrams and determine:
a) the ratio of the mass air and steam flows,

b) the required rate of heat input into the combustion chamber and

c) the thermal efficiency of the combined cycle.

A cylindrical storage tank contains liquefied propane under a pressure of 1.5 MPa (gage pressure P=1.5 MPa) and is subjected to a torque T=5 kN-m. Knowing that the tank has an inner diameter of 320 mm and a wall thickness of 3 mm, find the principal stresses and determine the maximum shear stress.

To provide a service to a town, water is taken from a dam and raised to a tank from where it is distributed to the neighborhood. The difference in levels between the dam and the tank is 600 feet; the length of the commercial steel pipe is 40,000 feet and the required flow is 8,000 gpm. Define:
a) the necessary pumping station
b) The type of pumps
c) The turning speed
d) Diameter of impellers
e) Power necessary to provide this service.

Time-Based Preventive Maintenance and Condition-Based Preventive Maintenance are two methods that are used in maintenance. Explain your understanding of the application of each and provide three examples of each method. In addition, discuss which is more effective and optimal.

The purpose of OSHA’s standard for the control of hazardous energy is to protect people in the workplace (from this hazardous energy) while they are performing service or maintenance on plant machines and equipment. Hence, to prevent the accidental or inadvertent activation of systems, while it is being serviced or repaired, provide a framework, in a sequential order, of the procedure for use of the controls and lockout/tagout devices.

A mass (10 kg) is sitting on a table. The coefficients of static friction (.5) and kinetic friction (.2). A chain is attached to the box, frictionless, and is attached to a pulley at the end of the surface and a ball(5kg)is attached to the hanging end of the rope. The system is released from rest. Write the equations that correspond to each mass. Determine the magnitude of the acceleration of the boxes.