Explain the nature of defect in casting process and identify the defects through various NDT techniques.
In: Mechanical Engineering
1. Provide at least three advantages and disadvantages of mask-based process compared to the stereolithography process.
2.Name three solid-based RP processes. Briefly explain fundamentally how each process transforms from a solid to form a part?
In: Mechanical Engineering
Wind Tunnel Experiment:
1. Using the manometer measurements, determine the two speeds with which the wind tunnel was operated. (1 mark)
2. Discuss how changes in Reynolds Number affect the flow separation and provide a source that supports your suggestion. (2 mark)
3. Discuss how the angle which separated flow is achieved varies for each tuft depending on its location and explain why this is occurring.
4. What flow structure can be identified at the tip of the wing and describe how the tufts react differently at this location?
5. Calculate the Static Pressure Coefficient over the wing using the static pressure values provided. (1 Mark)
CFD Analysis:
6. Describe your CFD methodology, meshing considerations and solution setup. Justify the decisions you have made for these parameters using results that you have obtained or by citing suitable references.
7. Determine the lift and drag for the wing at both angles of attack using the CFD model. (1 Mark)
8. Compare the flow fields for both angles of attack, describe and locate the key flow features such as those in the wake region and separation points if they exist.
9. Calculate the Static Pressure Coefficient over the wing and the velocity field in the wake from your CFD results and plot these over the corresponding experimental results provided. (2 Mark)
Discussion and Conclusion:
10. Include a detailed discussion comparing your CFD analysis and results with the wind tunnel results plotted in question 9. Identify any sources of error between the experiment and the CFD and determine how this may have affected the comparison between the two.
11. If you were asked to repeat the CFD analysis, what would you change in the setup of the model to better predict the flow features viewed in the wind tunnel.
Manometer (off) | Manometer (low) | Manometer (high) | |||||
Length (mm) | 255 | 330 | 403 | ||||
Height (mm) | 52.14649322 | 67.48369711 | 82.41190889 | ||||
Gradient (°) | 11.8 | 11.8 | 11.8 | ||||
Manometer reading at low speed: | |||||||
Tuft 1(°) | Tuft 2(°) | Tuft 3(°) | Tuft 4(°) | Tuft 5(°) | |||
1 | - | 16.8 | 14.1 | 15.1 | 12 | Trailing end | |
2 | - | 18.3 | 16.3 | 17.5 | 14.2 | ||
3 | - | 21.2 | 19.2 | 20.2 | 24.7 |
Leading Edge |
|
16.3°-Vortex becomes parallel to the wind tunnel | |||||||
Manometer reading at high speed: | |||||||
Tuft 1 | Tuft 2 | Tuft 3 | Tuft 4 | Tuft 5 | |||
1 | - | 16.6 | 13.7 | 15.2 | 12.1 | Trailing end | |
2 | 14.2 | 17.8 | 15.7 | 16.2 | 13.7 | ||
3 | - | 22.1 | 16.7 | 19.8 | 22.1 |
Leading Edge |
|
9°-Vortex becomes parallel to the wind tunnel |
In: Mechanical Engineering
3. Design and draw a circuit using the cascade system to operate two cylinders (A and B) which, on the operation of a start valve, produces the sequence A – B + B – A+. The cylinders should park in the positions B – A + when the start switch is in the ‘off’ position.
4. Modify the circuit designed for question 3 to provide an emergency stop which will park both cylinders in the extended position (i.e. A + B +).
5. Modify the circuit designed for question 3 to provide a fail safe. The fail safe should:
(a) act in the event of a reduced pressure at inlet to the group selecting valve
(b) park the cylinders in the retracted position
In: Mechanical Engineering
Design a four-link mechanism when the motions of the input and the output links are governed by a function y = x2 and x varies from 0 to 2 with an interval of 1.
Assume to vary from 50° to 150° and from 80° to 160°.
In: Mechanical Engineering
Working from first principles, derive an expression for the efficiency of an Otto Cycle engine in terms of compression ratio. Sketch the P-V diagram for this cycle and annotate it using the same station numbers used in your derivation. State why the efficiency must be less than that of the Carnot Cycle.
In: Mechanical Engineering
Working from first principles, derive an expression for the stagnation temperature of a perfect gas, in terms of flight velocity, specific heat at constant pressure and the ambient temperature.
In: Mechanical Engineering
a) Describe briefly how to develop a sensor using strain gauge. Your answer should be supported with figure(s) and block diagram showing the mechanical and electrical relation of the sensor [5 marks) Subject : Instrumentation
In: Mechanical Engineering
staybolts are most commonly used in ------ boilers.
In: Mechanical Engineering
Assess in details, the relevance of Mechanical Engineering to other disciplines going by the new technological trends.
In: Mechanical Engineering
If one side of the cavity wall of a Helmholtz resonator is a mass-spring oscillator, what will be natural frequency of the resonator?
In: Mechanical Engineering
Preamble:
Nico Case is an industrial engineer working in Vancouver, BC. Ms. Case is responsible for the design and development of a new warehousing operation for a national manufacturer of yoga clothing. Nico has several design alternatives available, each with differing types of equipment, production strategy, cost, and potential throughput. Accordingly, Ms. Case has decided to build a simulation model to guide her analysis. The following questions relate to this study.
Q 1a18. Ms. Case is interested in setting the warm up period for her model. She has run a pilot run of her simulation and output hourly throughput for her system. She receives the following data:
Time |
Rep 1 |
Rep 2 |
Rep 3 |
1 |
3 |
5 |
4 |
2 |
49 |
40 |
37 |
3 |
20 |
19 |
19 |
4 |
22 |
24 |
24 |
5 |
24 |
20 |
20 |
6 |
22 |
25 |
25 |
7 |
25 |
20 |
22 |
8 |
25 |
21 |
24 |
9 |
21 |
20 |
24 |
10 |
21 |
24 |
25 |
a) Define what is meant by "transient" as opposed to “steady-state" for a simulation model.
b) Why is it important to identify a warm up period for a simulation model?
c) Using Welch's technique and a moving window with w = 1, estimate the warm up period for this model.
In: Mechanical Engineering
Q 418. Using an LCG generator with parameters a: 21, m: 100, c: 13 and x0: 7 generate (if possible) a random variate from each of the following distributions. For each sub question, you may restart the LCG stream (i.e. feel free to reuse the same random number for each sub-question)
a. Normal (15, 5)
b. Gamma (5, 4)
c. Poisson (2)
d. Weibull (2, 2)
e.Triangular(1,2,5)
In: Mechanical Engineering
1. When recovery/recycling equipment is used to remove
refrigerant from a mobile A/C system, how much lubricant will be
removed during operation?
A. 4 ounces
B. Generally, very lttle, if any
C. The complete system lubricant charge
D. At least 6 ounces
2. Which SAE standard(s) must be referred to on the label of approved HFC-134a refrigerant recycling machines?
A. SAE J1988 or SAE J1627
B. SAE J1989 or SAE J2791
C. SAE J1990 or SAE J2297
D. SAE J2210 or SAE J2788
3. CFC-12 recovery equipment has SAE 3/8-inch service fittings.
HFC- 134a recovery equipment has:
A. 1/2 inch Acme threads
B. 10 mm threads
C. Quick-couple design
D. Same as CFC-12 recovery equipment
4. To recover and recharge refrigerant from an HFO-1234yf
system, a shop will need:
A. Only a new storage tank
B. A new recovery, recycling and recharging machine
C. No new equipment
D. A new compressor
5. To what does Global Warming Potential (GWP) refer?
A. Relative ability to warm a car cabin
B. Relative ability to produce global warming effect
C. A global attempt to address global warming
D. Relative ability to cool the planet
In: Mechanical Engineering
A horizontal pipe with a diameter of 4 inches abruptly connects to a larger pipe of 12 inches in diameter in an industrial application.
The flow is turbulent and the volume flow rate is 10
ft3/s in the smaller pipe and its pressure is 75 psia.
The water temperature is 70-degrees Fahrenheit and the kinetic
energy correction factor is 1.06 for the inlet and outlet
connection.
What is the loss coefficient, KL
What is the head loss in feet
What is the pressure in the larger pipe downstream from the
transition in psia
In: Mechanical Engineering