Large thin metal sheets of length L are dipped in an electroplating bath in the vertical position. Their average temperature is initially cooler than the liquid in the bath. How rapidly will they come up to bath temperature, Tb? Now please take the time out to explain your answer in detail, as well as, list all steps that led to this final answer.
In: Mechanical Engineering
Assume that you are appointed by a university as the technical
manager of the University's Formula-SAE-A Race Car project and you
are required to:
a) Identify the relationships between operational objectives and
functional requirements for the case of a new Formula-SAE-A Race
Car (F-SAE-A) in 2018. Cite three operational objectives and the
functional requirements that are needed to realise these objectives
via using qualitative measures only; and
b) What is meant by “MOE”? For the effectiveness analysis of the
F-SAE-A, list what you think would be the 10 most important
characteristics that should be exercised and measured in the
analysis. For one of the MOE of the F-SAE-A, describe an
operational scenario for obtaining a measure of its
effectiveness.
In: Mechanical Engineering
As a systems engineer, you are required to do a trade study on common coffeemakers available in market. Conduct product research and narrow down your choices to five products. Please conduct the following steps:
i. Develop a top - level function list for a common coffeemaker, limiting yourself to no more than 12 functions; ii. Draw an FBD of the coffeemaker using the functions in
(i); iii. Convert the coffeemaker FBD to an IDEF0 diagram and a UML activity diagram respectively;
iv. Identify exactly four selection criteria, not including purchase price or operating cost;
v. Assign weights to each criterion, explaining in one sentence your rationale;
vi. Construct a utility function for each criterion — describe it verbally or graphically; vii. Research the actual values for your criteria for each alternative; viii. Perform the analysis, calculating a weighted sum for each alternative;
ix. Calculate the effectiveness/unit cost for each alternative using purchase price for cost; and
x. Describe your choice for purchase, along with any rationale.
In: Mechanical Engineering
A nuclear fuel element is in the form of long solid
cylindrical rod (k=0.85 W/mK) of diameter 14 mm is generating heat
at an uniform rate of 0.45×108 W/m3 because of nuclear fission.
Heat is transfer to pressurized cooling water at 300 0C and surface
heat transfer coefficient is 4500 W/m2k. calculate the maximum
temperature in the fuel rod in the system. What is the change in
Tmax if the fuel element is encapsulated in a thin metal cladding
of thickness 0.5 mm. Neglect thermal resistance of the
cladding.
In: Mechanical Engineering
A model of Francis turbine one fourth of full size develops 2.8 kW at 300 r.p.m. under a head of 1.75m . find the speed and of full size turbine operating under a head of 5.2. 1. if efficiency of the model and full size turbine are the same. 2. the efficiency of the model turbine is 80% and the scale effect is considered
In: Mechanical Engineering
A bathtub curve consisting of three linear regions as a function of time (t), namely:
1. an infant mortality failure rate that decreases as landa(t) = C1 -C2t
2. A zero random failure rate.
3. A wear out region that varies as C3(t-t_0)
a) Sketch the bathtub curve, labeling each region carefully.
b) calculate f(t) and F(t) values in each of the three regions.
c) sketch and explain clearly what happens to the bathtub curve as component dimensions shrink further.
d) sketch and explain what happens to the bath tub curve as devices are powered under sucessive higher current voltage stressing.
In: Mechanical Engineering
Using current rapid prototyping technologies, production parts are produced. a. Never b. Always c. Rarely d. Cannot answer this question based on the information provided.
In: Mechanical Engineering
Why is gravity considered in the torque?
In: Mechanical Engineering
Q1 (a)0.5 kg of water is contained in a rigid vessel at a temperature of 125oC and a pressure of 232.1 kPa. The specific enthalpy is 1050 kJ•kg-1. Which of the following could also be correct?
(A) v = 0.001065 m3 •kg-1 (B) v = 0.7706 m3 •kg-1 (C) x = 0.24 (D) x = 0.5
(b).0.020 kg of air, initially at 20oC is compressed in a perfectly insulated and sealed cylinder which is fitted with a moveable piston. A mean force of 1000 N was applied to the piston as it moved through a displacement of 100 mm to compress the gas. The final temperature of the gas after compression will be?
(A) 27oC (B) 20oC (C) 30oC (D) 13oC
(c). 0.8857 m3 of H2O is stored in a rigid vessel at 200 kPa, 125oC. Is this?
(A) Sub-cooled liquid ? (B) Saturated liquid ? (C) Saturated vapour ? (D) Superheated vapour ?
In: Mechanical Engineering
This chapter applies the energy equation to a pipe flow system. You need to be
able to identify (draw) a control volume for the analysis for the pipeline.
In: Mechanical Engineering
The entrance length can be significant when the pipe length is not relatively long.
How do you determine the entry length and how it compares to the total pipe
length? If the entry length is ignored what does that do the accuracy of the
predicted pressure drop, is it too high or too low?
In: Mechanical Engineering
Look at Table 5.2 – read over the often used nondimensional groups. No need to
memorize these but they might provide a guide as to what Pi groups should
appear in a problem
In: Mechanical Engineering
A particle travelS along the circular path from A to B in 1s. If it takeS 3S for it to go from A to C. Determine Its average velocity when it goes from B to C.
In: Mechanical Engineering
A major retail firm is considering a major change in its distribution system. It is considering relocating its distribution centers such that all retail stores can be replenished within 24 hours of a request for merchandise.
The table below is a matrix of cover coefficients for 10 stores and 10 potential sites for distribution centers. If store i can be replenished within 24 hours from site j, then a_ij=1; otherwise a_ij=0. The cost of installation of the distributions centers vary from zone to zone and are given in the DC cost row. The firm wants to find the optimal location of the distribution centers.
Store i |
Distribution Center Site |
|||||||||
1 |
2 |
3 |
4 |
5 |
6 |
7 |
8 |
9 |
10 |
|
1 |
1 |
1 |
0 |
0 |
0 |
0 |
0 |
1 |
1 |
1 |
2 |
1 |
1 |
1 |
0 |
0 |
0 |
0 |
0 |
0 |
0 |
3 |
1 |
1 |
0 |
1 |
1 |
0 |
0 |
1 |
1 |
0 |
4 |
0 |
0 |
1 |
0 |
1 |
1 |
1 |
0 |
1 |
1 |
5 |
0 |
0 |
1 |
1 |
0 |
1 |
1 |
1 |
1 |
0 |
6 |
0 |
0 |
0 |
1 |
1 |
1 |
1 |
0 |
0 |
1 |
7 |
0 |
1 |
0 |
1 |
0 |
1 |
0 |
1 |
1 |
0 |
8 |
1 |
1 |
1 |
0 |
1 |
0 |
0 |
1 |
1 |
1 |
9 |
1 |
0 |
1 |
1 |
1 |
0 |
1 |
0 |
0 |
1 |
10 |
0 |
0 |
1 |
0 |
0 |
1 |
1 |
1 |
1 |
1 |
DC COST |
193 |
721 |
822 |
156 |
607 |
593 |
246 |
385 |
309 |
867 |
1-Provide a mathematical formulation of above model
2-Provide a mathematical formulation given a budget restriction of 300.
3-Provide a mathematical formulation given a coverage target more than 85% (firms wants to cover at least 85% of the stores)
3-Solve the 3 models using Lindo/Excel Solver or any optimization software you know
In: Mechanical Engineering
Consider the following schematic for an experiemental methodology to measure the convection heat transfer coefficient distrubution on an airfoil. The metal sheathing is supplied with a heat generation rate of 20 * 106 W/m3. The thickness of the metal sheathing is t = 30 um, and the sheathing's thermal conductivity is k=25 W/mK. The 30 surface locations where the temperatures are measured are spaced evenly at 2mm apart. The measured temperatures are listed in the table below.
Location | Temperature (degrees C) |
1 | 29.77 |
2 | 29.67 |
3 | 29.71 |
4 | 29.83 |
5 | 30.06 |
6 | 30.47 |
7 | 30.98 |
8 | 31.67 |
9 | 32.66 |
10 | 34.18 |
11 | 36.29 |
12 | 38.78 |
13 | 41.29 |
14 | 43.51 |
15 | 44.68 |
16 | 44.84 |
17 | 43.29 |
18 | 39.89 |
19 | 36.51 |
20 | 34.36 |
21 | 33.13 |
22 | 32.64 |
23 | 32.63 |
24 | 32.77 |
25 | 33.16 |
26 | 33.52 |
27 | 33.85 |
28 | 33.51 |
29 | 31.91 |
30 | 30.42 |
Accounting for conduction in the metal sheathing, detemine the convection heat transfer coefficients at the 30 numbered locations.
In: Mechanical Engineering