In: Mechanical Engineering
Air flows over a 4 meter long flat plate at a velocity of 8 m/s. Using a spreadsheet, calculate the boundary layer thickness and wall shear stress at 0.1 meter intervals along the plate. Do not plot the wall shear stress at x=0. Use a transition Reynolds number of 5 x 10^5 . (You will need to calculate Rex at each location to determine if the laminar or turbulent correlations should be used.) Generate a spreadsheet table that includes columns for the x location, Reynolds number, boundary layer thickness, and wall shear stress. Also include the exact transition location in the x column. At the transition location, calculate both the laminar and turbulent correlations and include both values in your plot. (The solution will have a jump at the transition point.) Plot your results for the boundary layer thickness and wall shear stress on separate plots. Submit a copy of your EXCEL table and the plots you generated. Include a plot title and label the axes with the variable name and units. Use only lines, no symbols, to show your analytical solution.
In: Mechanical Engineering
Im designing a boat anchor winch that anchors a load of 1000 kg into the water when the boat is stationary with a wire line from the winch to the anchor, I came up with a spur gear design a pinion gear 1 and gear 2. Gears is made of carbon steel. For that application what is the correct motor to connect into the spur gear. How much horseower does gear 1 and gear 2 need to operate a 1000 kg load. You can estamate the rest of the variables.
In: Mechanical Engineering
The flight test data for a given airplane refer to a level‐flight maximum‐velocity run made at an altitude that simultaneously corresponded to a pressure altitude of 30,000ft and density altitude of 28,500ft. Calculate the temperature (in °F) of the air at the altitude at which the airplane was flying for the test.
In: Mechanical Engineering
The person’s mass, m= 68.1 kg, the unknown drag coefficient is,
c , with units kg/s, and the local acceleration of gravity is g=
9.80 m/s2 . Our model for the person’s velocity vs time gave us a
linear differential equation whose analytical solution was the
following:
V(t) = g*m/c*[1-exp(-c/m*t)].
Your job is to find “c”. You need to use the MATLAB “help”
documentation to find the nonlinear curve fitting function and
syntax for how to use it. Hint you should use the documentation and
example for “lsqcurvefit”.
Include in your program a plot of the experimental velocity data vs
time and the calculated velocity vs time. The graph should have a
title, x and y labeled axis, and a legend. It is likely your legend
will not be placed in a good position. Use again the MATLAB “help”
documentation to learn how to move it to the southeast corner
inside your plot.
The following table is experimental data regarding our
parachutist. We have a measured velocity versus time after the
jump, but before the chute is opened:
Time t (sec)
Velocity, cm/s
0
1
1000
2
1630
3
2300
4
2750
5
3100
6
3560
7
3900
8
4150
9
4290
10
4500
11
4600
12
4550
13
4600
14
4900
15
5000
In: Mechanical Engineering
As an experienced engineer, suggest two (2) alternatives to reduce the electrical usage and cost for air ducting unit . The alternative suggested should comprise one (1) technical modification and one (1) human feature.
In: Mechanical Engineering
Why is it that heat pumps are rarely used in the UK to heat homes? However in a remote region there may be reason to use such a system. What type of system might you recommend and what would be the criterion to justify the heat pump as an alternative to a simple oil boiler?
GIVE FULLY EXPLAINED AND TYPED ANSWER
In: Mechanical Engineering
You are the head of the engineering department in a certain company. your department has been allocated an annual budget of R2.6 million for this year. it is now towards the endof the financial year and your department has overspent by 25%. your senior manager wants you to justify why this is so. YOur task is to present a report showing all the expense of your department for the year and analyse them in a form of a Pareto analysis and a drill down analysis. in your analysis, ensure that you highlight the cause of your over expenditure, including the failure modes of the equipment. Justify ypur financial over spend with things that affect maintenance such as economic factors (macro and micro), poor workmanship from contractors, shift arrangements, poor quality spares, emergency work that had to be done etc. your report must include at least 3 internet sources and 3 textbook sources.
please include graphs for pareto and drill down analysis or onstructions on how to go about doing it
In: Mechanical Engineering
As a body is projected to a high altitude above the earths surface, the variation of the acceleration of gravity with respect to altitude y must be taken into account. Neglecting air resistance, this acceleration is determined from the formula a=−g0[R2/(R+y)2], where g0 = 9.81 m/s2 is the constant gravitational acceleration at sea level, R = 6356 km is the radius of the earth, and the positive direction is measured upward.
With what velocity does the particle strike the earth if it is released from rest at an altitude y0 = 750 km?
In: Mechanical Engineering
What is the most frequently failed (engineering) product that you have observed in your life? Be specific about your failed product. If you are given a chance to redesign and choose appropriate materials, how would you go about it?
In: Mechanical Engineering
The top surface of a rectangular work part is machined in a peripheral milling operation. The work part is 735 mm long by 50 mm wide by 95 mm thick. The milling cutter, which is 65 mm in diameter and has five teeth, overhangs the width of the part equally on both sides. Cutting speed = 60 m/min, chip load = 0.20 mm/tooth, and depth of cut = 7.5 mm.
(a) Determine the time required to make one pass across the surface, given that the setup and machine settings provide an approach distance of 5 mm beforeactual cutting begins and an over travel distance of 25 mm after actual cutting has finished.
(b) What is the maximum material removal rate during the cut?
(c) If the workpiece has surface scale, would you recommend conventional milling or down milling? Why?
In: Mechanical Engineering
1)Consider water at 500 kPa and a specific volume of 0.2 m3/kgm3/kg. What is the temperature (in °C)?
2)Consider water at 500 kPa and a specific volume of 0.2 m3/kgm3/kg. What is the quality (on a 0 to 1 scale)?
3)Consider water at 1400 kPa and 200°C. What is the specific volume (in m3/kgm3/kg)?
In: Mechanical Engineering
to build a robot capable of handling 150lbs.how do I
pick a motor considering all of the specs I see are for example
rpm=2500 volts=12 gear ratio = 10:14.
I am new to this so all the info I can get will help.Thanks
In: Mechanical Engineering
What is meant by:
1. Hydrophilic?
2. Hydrophobic?
3. Surface wetting?
4. Capillary action?
Please type your answer, do not write it.
In: Mechanical Engineering
a) What are the disadvantages of using single coil springs for mechanical seals? b) What are the main advantages associated with the use of multi-coil springs?
In: Mechanical Engineering