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Question Description

I’m working on a mechanical engineering project and need a sample draft to help me learn.

Hello,

I need a lab manual for a topic from the mentioned topics in the assignment description, please follow the guidelines and write everything according to the rubric. Please choose the topic that you think would be suitable for you. Attached are both the description and a sample lab manual from class. please include equations, tables, and everything needed. Thanks

EML 3303 – Term Project
Goal
Design a brief lab session (similar to the ones you have taken throughout this course) and write
the lab manual. The project is to be completed in groups, same groups as in labs. You will
submit one thing:
a) A written document (pdf) in the form of a lab manual: no more than 5-6 pages
approximately.
Due date
Friday, December 3rd by midnight (11:59PM) 2021.
What to do:
Think of a physical variable/material property that is typically measured in mechanical
engineering and design a brief laboratory session that shows how to conduct measurement(s)
for such variable.
IMPORTANT: you cannot choose a physical variable that can be directly measured with an
instrument. It has to be an indirect measurement. For example, you cannot choose mass as the
physical variable since a scale can directly provide that measurement. Instead you could choose
density and measure mass and volume in order to find density.
Once you pick a physical variable/material property you will:
– Choose real measuring devices/instruments/sensors to carry out the measurement you
picked.
– Explain how the measuring devices/instruments/sensors work.
– Describe in detail step by step how to use the measuring devices/instruments/sensors to
eventually obtain the desired measurement.
Written document structure
The written document you submit should have the following sections:
Cover page: Project title, Authors names.
1 – Introduction: goal of the lab session and context for the measurement. Relate it to real
applications. Where does this measurement occur? Who uses it? What is it used for? Why is it
important?
2 – Theory: here you will present the measuring devices/instruments/sensors needed to
conduct your measurement and the fundamental principles behind such devices. Choose real
existing measuring devices/instruments/sensors and provide the manufacturer/seller and
model numbers. Also, you will include any equations required for your measurement and
explain them briefly and clearly.
3 – Procedure: explain in full detail, step by step, how to use the measuring
devices/instruments/sensors to conduct your measurement. Use a bulleted list for the
procedure.
4 – Uncertainty: list the sources of uncertainty for the measuring devices/instruments/sensors
you decided to use and provide the formulas to be used to calculate the uncertainty of the
physical variable/material property you chose for this project. You are not required to use
numerical values, although you may choose some hypothetical ones if you would like.
Ideas (here are some ideas that you can borrow or you can come up with your own)
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Measuring the drag coefficient of spherical objects.
Measuring the flow coefficient (Ko) of a differential pressure flow meter.
Measuring the Young’s Modulus of a metal.
Measuring material hardness with the Vickers and Brinell methods.
Measuring distance with optical techniques.
Measuring sound wave attenuation through a solid material.
Measuring the thermal conductivity of a material.
Measuring the specific heat of a material.
Measuring the density of an ideal gas.
Measuring solar irradiance on a flat surface.
Measuring the Poisson’s ratio of a solid material.
Measuring the resistivity of a material.
Measuring the electrical conductivity of a metal.
Measuring corrosion.
Measuring surface tension in a liquid.
Measuring the Seebeck coefficient of a thermoelectric material.
Measuring the Shear Modulus.
Measuring material toughness.
Measuring the thermal expansion coefficient of a metal.
Measuring fracture toughness against surface cracks.
Measuring magnetic permeability.
Measuring the speed of sound in liquids with ultrasonic transducers.
Lab 2
Pneumatic Cylinder
Objective
Introduction to:
• Pneumatic Cylinders
• Propagation of Uncertainty
Introduction
A pneumatic cylinder converts energy stored in a pressurized gas into mechanical work. The high
pressure air exerts a large force on one side of the piston and the low pressure air exerts a smaller
force on the other side of the piston, resulting in a net force given by equation 1a (pressures are
gage pressure, not absolute pressure). This force causes the piston (and the attached rod) to extend
or retract, depending on the direction of the net force. If the low pressure side is at atmospheric
pressure, then equation 1a becomes 1b, which is the case in this lab.
𝑭 = 𝑷𝒄𝒂𝒑 ∗ 𝑨𝒄𝒂𝒑 − 𝑷𝒓𝒐𝒅 ∗ 𝑨𝒓𝒐𝒅
𝑭=𝑷∗𝑨
(1a)
(1b)
The terminology used in pneumatic cylinders refers to the larger area (left side of the piston in
figure 1) as the “cap” side of the piston and the smaller piston area (right side of the piston in figure
1) as the “rod” side of the piston. Notice that the rod side area is smaller than the cap side area.
Also, note that Arod in this case does not refer to the area of the rod, but rather, the area of the rod
side of the piston. Figure 1 depicts the anatomy of a typical pneumatic cylinder. These devices
are also known as linear actuators because they produce linear motion.
Figure 1: Anatomy of a typical air cylinder
The advantages of using a pneumatic cylinder:
• Air cylinders are relatively quiet in operation
• Air cylinders are clean – there is no hazardous fluid that can leak into the surroundings
• Initial cost is low
The disadvantages of using a pneumatic cylinder:
• Can lack precision if the load on the cylinder is compressing the gas as the cylinder actuates
(i.e. extending or retracting in vertical position)
• Relatively poor speed control
• The long term cost of the increased energy required run the air compressor
Single-acting cylinders (SAC) – Air cylinders which have only one air supply to push the piston
only one way. A SAC type air cylinder usually has an internal compression spring resetting the
piston after actuation.
Double-acting cylinders (DAC) – Air cylinders that have air supply ports on both ends. This type
of air cylinder is more controllable (position and speed) by controlling the differential pressure on
both air supply ports.
One-sided cylinder – A cylinder with a rod extending out in only one direction. This is what is
being used in this lab.
Two-sided cylinder – A cylinder with a rod extending out of each side. Typically the rod diameter
is equal on both sides, resulting in simplified analysis because both sides of the piston will have
the same area.
Bore – Refers to the diameter of the cylinder barrel in which the piston travels. This dimension
will be used to calculate the piston area.
Position Sensors (Switches) – The cylinder’s speed and position can be controlled by having a
magnetized piston traveling inside the cylinder barrel. The position of the magnetized barrel can
be sensed by position sensors (switches) attached to the outside of the cylinder barrel via the Hall
effect.
Tools and Material
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1 Air cylinder setup with two On/Off switches
1 Air regulator/filter
1 Dissected air cylinder (one per class)
1 load scale (aka. fish scale)
1 Vernier caliper
Procedure
1. Make sure that all laboratory tools are present and properly working.
2. With a caliper, measure the inside diameter of the provided pneumatic cylinder. A
dissected air cylinder will be provided so that the inside diameter is accessible. Each
member of the group should perform this measurement twice. Record your measurements
in the table provided in the back of this laboratory.
3. With a caliper, measure the diameter of the air cylinder rod. Each member of the group
should perform this measurement twice. Record your measurements in the table provided
in the back of this laboratory.
4. Familiarize yourselves with the set-up, valves, pressure regulator, and gages. Be sure you
know which direction to turn the valve switches (A and B) to turn supply air pressure on
and off.
Caution: While under pressure the cylinder can snap quickly and cause minor injuries
so take caution when switching air supply switches!
5. Record the force exerted by the extending air cylinder at approximately 40 psi. Without
adjusting the regulator, record the force exerted by the retracting air cylinder at the same
pressure. Carefully monitor regulator readings and allow it to settle to steady state before
recording the data.
6. Repeat step 5 for each pressure setting required. The pressure should range from
approximately 5 psi up to 40 psi. It is important that you leave the pressure regulator setting
unchanged while measuring the extension and retraction force because it would be difficult
to achieve the identical pressure after adjusting the regulator.
Calculations
1. Plot cylinder performance (do in lab)
Compare the extending and retracting forces, that is, compare measured forces to the forces
calculated (theoretical) from your area and pressure measurements. For each force
direction (extension and retraction), plot graphs with force on the vertical axis and pressure
on the horizontal axis, clearly indicating units. Make sure your data looks reasonable.
2. Find the uncertainty in the cylinder extension force measurement (do in lab)
From your caliper measurements, estimate the error in surface area. Also estimate the error
in pressure from your experience in setting the pressure at the regulator. Finally, use
Equation 1b with equation 2, 3, and 4 to estimate the error in your force calculation. Be
sure to check your units, whether you use English or SI units.
The uncertainty of the extending or retracting cylinder force, can be found with Equation
2. This provides the ‘most likely error’.
4
1.
1.
𝑢. = /012 𝑢2 3 + 016 𝑢6 3
1.
12
= 𝐴 and
1.
16
4
(2)
=𝑃
(3),(4)
Substituting Equations 1, 3, and 4 into Equation 2 and rearranging gives Equation 5.
9:
.
4
9
9
= /0 2;3 + 0 6? = 𝜋𝑑 4 /4
(For Extension Only)
(6)
Applying the same method used to get Equation 5, we get the uncertainty in the area to be
16
4
𝑢6 = /01E 𝑢E 3 = /02
GE
H
4
𝑢E 3 = 2
GE
H
|𝑢E |
(7)
𝑢E is the uncertainty of the cylinder inner diameter. This 𝑢6 can then be used to solve for
𝑢. (Equation 5). These equations are for the extension when the pressure acts on the entire
area.
Looking at equation 5, you can see that the uncertainty will change depending on the value
of F and P, so your uncertainty will be different for each measurement – calculate the
uncertainty of the calculated force for each pressure on extension mode only.
Check to see if the measured force is within the bounds of uncertainty of the calculated
force. If not, what do you think could account for the differences?
3. Uncertainty on retraction force
The equations change for retraction when the area of the rod must be subtracted. Derive
the equations needed to find the uncertainty on the retraction force and present them in the
appendix. No numerical values required.
Lab Report
This report is to be completed in groups (one printed report per group). The report should also
include the following graphs as part of the results:
1. One scatter plot of the measured force for extension and retraction VS air supply pressure
(2 sets of points on plot)
2. One scatter plot of the calculated force for extension and retraction VS air supply pressure
(2 sets of points on plot)
3. One scatter plot of the measured force for extension and the calculated force ± Force
Uncertainty (𝑢. ) VS air supply pressure. (two lines, one with Error bars)
Figure 2 presents a general sample plot formatted properly in Microsoft Excel.
Pneumatic Cylinder Extension Force vs. Supply
Pressure
Force (lbs)
150
100
Measured force
50
Calculated force
0
0
20
40
Pressure (psi)
60
Figure 2: Example of cylinder extension vs supply pressure plot created in Microsoft Excel.
As always, normal formatting rules for any graphs and tables apply (axis labels, caption, table title,
etc). Remember to still include tables with the calculated values. Include a discussion of
observations and trends for each graph and discuss what would need to be done to reduce the error
in the force measurement and calculation.
Review the lab report formatting requirements and pay attention. They are not suggestions. Upon
reading your lab report, if it becomes clear that you have not read the lab report guidelines or made
a reasonable effort to adhere to them, you will receive a zero on your lab report with no opportunity
to resubmit and with no detailed feedback.
Data Sheet
Pressure
Regulator
Setting
(_____)*
Cylinder
Extension
Force
(______)*
Cylinder
Retraction
Force
(______)*
*Record units used
Cylinder Inside Diameter
(_______)*
Lab
Partner
Measurement 1
Measurement 2
Cylinder Rod Diameter
(_______)*
Measurement 1
1
2
3
4
*Record units used
Measurement 2
Appendix:
Why do we use gage pressure instead of absolute pressure in the above analysis?
The absolute pressure ultimately is what determines the force. Consider all the forces acting on
the piston-rod assembly in the direction of motion:
1) the absolute pressure in the cap side acting on the cap side area
2) the absolute pressure in the rod side acting on the rod side area
3) the absolute pressure (atmospheric) acting on the tip of the rod
4) friction between the cylinder wall and the piston.
Conveniently, the friction force goes to zero as the piston velocity goes to zero, leaving the other
3 forces. The resulting force is given below
𝐹 = (𝑃L,=>? + 𝑃>NOPQ?RSTU= )𝐴=>? − (𝑃L,TPW + 𝑃>NOPQ?RSTU= )𝐴TPW − 𝑃>NOPQ?RSTU= ∗ 𝐴TPW NU?
But notice that 𝐴=>? = 𝐴TPW + 𝐴TPW NU? so that the above equation simplifies as follows:
𝐹 = 𝑃L,=>? 𝐴=>? + 𝑃>NOPQ?RSTU= 𝐴=>? − 𝑃L,TPW 𝐴TPW − 𝑃>NOPQ?RSTU= 𝐴TPW − 𝑃>NOPQ?RSTU= ∗ 𝐴TPW NU?
𝐹 = 𝑃L,=>? 𝐴=>? + 𝑃>NOPQ?RSTU= 𝐴=>? − 𝑃L,TPW 𝐴TPW − 𝑃>NOPQ?RSTU= (𝐴TPW + 𝐴TPW NU? )
𝐹 = 𝑃L,=>? 𝐴=>? + 𝑃>NOPQ?RSTU= 𝐴=>? − 𝑃L,TPW 𝐴TPW − 𝑃>NOPQ?RSTU= (𝐴=>? )
𝐹 = 𝑃L,=>? 𝐴=>? − 𝑃L,TPW 𝐴TPW

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