What techniques can be used to predict the failure of machine/equipment for
the purpose of preventive maintenance.

Performance evaluation of cold tube heat exchanger for various L/D ratio and mass flow rate.   using Ansys show the temperature distribution.   and make a mathematical model in scilab and perform simulation in fortran 77...

A single start square- thread power screw has a diameter of 2 inches and a pitch of .4 inches.

Calculate the:

1. Lead
2. Mean pitch diameter
3. Lead angle (λ)
4. Normal angle (αn

Task 1
Company 1 is new into distillation & separation has approached CD19 for support on the following problem: -
(a) They wish to separate a 50-gram sample of a new liquid compound, by heating it in a reactor to convert it from liquid to gas. The final pressure of the gas should be 775 mmHg at 24oC. They are struggling to find the volume of the reactor. Can you help? What volume of the reactor will be required to achieve the stated requirements?

(b) Another placement student suggests that by chilling the gas by 15oK will reduce the size of the reactor. Is the second engineer correct and by how much would the volume change?

(c) The temperature and pressure effects on a liquid can be described by the kinetic molecular theory. The customer would like you to explain this in a short and concise manner.
You are expected to draw a diagram (labeled) of the relationship between temperature and pressure for a liquid that is heated to form an ideal gas. Relative phase compositions should also be labeled.

Data
MWSample = 550 g/mol
1 mmHg = 133.32 Pa

Write the Conservation of mass equation as it applies TO YOUR SYSTEM

• Write the Conservation of Energy equation as it applies TO YOUR SYSTEM

• List all the assumptions and idealizations for the process

Diesel cycle

Fuel being used is diesel

1 cylinder, four-stroke, water-cooled, air injection of fuel
Output: 14.7 kW (20 hp)
Fuel consumption: 317 g/kWh (238 g/hp-hr)
Efficiency: 26.2%
Number of revolutions: 172 min^-1
Displacement volume: 19.6 L
Bore: 250 mm
Stroke: 400 mm

A gas turbine power plant operates on a Brayton cycles has a pressure ratio of 7. Air enters the
compressor at 300 K. The energy in the form of heat is transferred to the air in the amount of 950
kJ/kg. Using a variable specific heat for air and assuming the compressor isentropic efficiency is
83 percent and turbine isentropic efficiency is 85 percent. Determine the followings:
(i) The highest temperature in the cycle [5 marks]
(ii) The net work output, in kJ/kg [10 marks]
(iii) The back work ratio [5 marks]
(iv) The thermal efficiency. [5 marks]
(v) Show the cycle on T-s diagram [5 marks]

Use your mechanical engineering skill. Explain in 200 - 250 words why DOE is important for a Mechanical Engineer using an example. In this section, it is not expected you implement DOE in one full example. The idea in that you reflect DOE understanding in a Mechanical field. Feel free to use any source but the answer must be thorough.

Please type, make it easy to understand.

Ideal Reheat Steam Cycle (10)

Consider a steam power plant operating on the ideal reheat Rankine cycle. Steam enters the high-pressure turbine at PH MPa and TH °C and is condensed in the condenser at a pressure of PL kPa. Assume the steam is reheated to the inlet temperature of the high-pressure turbine, and that pump work is NOT negligible. If the moisture content of the steam at the exit of the low-pressure turbine is not to exceed w% percent, determine:

(a) the pressure at which the steam should be reheated and show how you got the quality,

(b) the total turbine work ,

(c) the net work ,

(d) the total heat input , and

(e) the thermal efficiency of the cycle .

PH = 20 MPa, TH = 700 °C, PL = 10 kPa and w% = 12.9%.

Determine the adiabatic combustion temperature at constant pressure and at constant volume for two of the fuels of personal choice. Graphically show that this corresponds to the product temperature where the heat of reaction is zero.

At a point in a stressed body, the principal stresses are 100 MN/m2
(tensile) and 60 MN/m2
(compressive). Determine the normal stress and
the shear stress on a plane inclined at 50degree
counter clockwise to the axis
of minor principal stress. Also, calculate the maximum shear stress at the
point and draw the Mohr’s stress circle to verify the answers.
If the yield strength and Poisson’s ratio of the material in the above case
is 240 MPa and 0.3 respectively, check whether the failure will occur or
not according to (a) Maximum principal strain theory and (b) Maximum
shear strain energy per unit volume theory. If failure does not occur,
calculate the Factor of Safety.

An air-standard dual cycle has a compression ratio of 14. At the beginning of compression, p₁ = 14.5 lbf/in.², V₁ = 0.5 ft³, and T₁ = 50°F. The pressure doubles during the constant-volume heat addition process.


For a maximum cycle temperature of 3500°R, determine:

(a) the heat addition to the cycle, in Btu.

(b) the net work of the cycle, in Btu.

(c) the percent thermal efficiency.

(d) the mean effective pressure, in lbf/in.²

Question 1

(a)   For the nucleation process, explain the difference between homogeneous and heterogeneous nucleation. Why heterogeneous nucleation is more common than

homogeneous nucleation.

(b) (i) Sketch and label the cross-section view of common macrostructure of a metal ingot after solidification process.
(ii) If the molten metal is added with 2 wt% of grain refiner, explain how the grain refiner changes the macrostructure of this metal ingot.

(c)   What is the difference between point defect and line defect?

(d)   Briefly explain why vacancies and self-interstitials are considered as the crystal defects?

Name and explain three processes that done after printing the design to have it in its final state?

Do all technologies need those processes, which one needs minor after processing?  

3D printing

Saturated liquid refrigerant R-134a is throttled from 900 to 90 kPa at a rate of 0.32 kg/s. What is the rate of entropy generation for this throttling process? kW/K