Image from M Moran, H Shapiro et al, Fundamentals of Engineering Thermodynamics 8th edition, Wiley, 2014
Kenneth Katz and Nicholas Krupka
DRAFT: Spring Semester, 2021
Lab report format
On the course Canvas page is a Module called Lab Reports. Files needed for the Lab Reports will be posted there. ‘Notes for Lab Reports’ concerns format and writing issues. ‘Sample Scientific Paper’ illustrates professional standards for using images, schematics, tables, and references in a scientific or engineering report.
The lab report is to be prepared in groups of 3 or 4 people (assigned by the instructor) and must be submitted through Canvas in PDF format (one copy per group).
The lab report must be typed in Microsoft Word and have equations, schematics, tables, and figures embedded in the report. Hand-written page(s) will not be accepted as part of the lab report and will result in a zero as report grade. More report requirements:
1. Cover page: contains lab title, group member’s names, date, and title of the experiment (use the provided format available on canvas).
2. Equations must be inserted (not typed as text or included as an image). In Word, open the tab Insert, on the right, in the Symbols section click on Equation and then Insert new Equation.
3. Sections (introduction, results, conclusions, etc..) must be clearly separated.
4. Font: Calibri (body).
5. Body font size: 11 or 12.
6. Section title font size: 12 or 14 (bold and underlined).
7. Justified on both left and right sides.
8. Specify the meaning of the symbols used (especially if they are not of common use).
9. Include figure numbers and a caption beneath each figure. Graphs are figures.
10. Figure captions must include a short statement that ‘titles’ the figure followed by at least one sentence that comments further on the image. Captions should be in a smaller font, and may be in Italics or bold or both to distinguish the caption from the main text.
11. Include table numbers and titles. Figures have captions beneath them. Tables have titles above them.
12. Include equation numbers. Place these in parentheses at the right hand margin.
13. The graphs indicating the experimental results and the analytical results must be neat and legible. If a curve is obtained from the analysis, a solid line must be used. If a curve is obtained from an experiment, a dotted line must be used. If more than one line is presented in the graph, they must be clearly distinguishable, even when printed in black and white by using different point shape or different dotted lines. The graphs must include the following elements:
13.1. Horizontal axis title
13.2. Vertical axis title
13.3. Legend (if more than once curve is present in the same graph)
13.5. Caption (not a title) as graphs are figures.
14. Writing notes: On Canvas please read the document “Notes for Lab Reports”. We will take Lab Reports as a chance to develop some technical writing techniques.
1. Boiling Water – Systems, Properties, States, P-v-T diagrams
This Lab Report will have three parts.
Part 1 (45/100 POINTS) based on Demonstration 1, will require data collection and plotting of data, making a hypothesis from the data, setting thermodynamic system boundaries, and identifying thermodynamics properties and states
Part 2, (45/100 POINTS) based on a print description of an experiment from the 1600’s, involves using provided data and description of a system and process to calculate changes in temperature, pressure, and other properties. Use of EES and Table A-2 will be practiced.
Part 3, (10/100 POINTS) based either on provided data or data that can be taken in a typical kitchen, involves solving a theoretical problem based on observed data with the help of data tables and EES.
Parts 2 and 3 include reference information about how to use EES for the problems in this Lab Report.
Known: The experiment involves an open pot of clean water being heated with an electric hot plate. A resistance temperature detector (RTD) is used to measure the heating coil temperature [T1], K-type thermocouples are used to measure the temperature of the water [T2] and the region above the water [T3]. A watt meter is used to measure the electrical power input to the hot plate [W]. The room conditions can be assumed as 25°C and 100kPa.
For further reading on the instruments used in lab, please refer to the following links:
https://www.omegaeng.cz/temperature/z/thertd.html (More Technical)
Typical Temperature Measurement Devices
Students are assigned roles to either keep time, read instruments, or record data. The hot plate is started and run for at least 5 minutes. Students not attending the Demonstration in person may use the following sample data:
Figure 1.1 – Sample data from Demonstration 1. If you are a PSV student or did not attend the Demonstration, you may use this data set.
Lab report content for Part 1
In order to get full credit for Part 1, each report must contain:
1. Introduction: describe the objective of the experiment giving reasons why we are performing this experiment; provide the necessary equations or list any tables from Moran & Shapiro that may be used to analyze this data.
2. Procedure: provide a description of the experiment steps and the apparatus/tools used including a schematic. Give a brief account of the working principles of the temperature detection devices used. If needed cite references with footnote numbers that direct the reader to a ‘References’ section at the end of your report.
3.1 Use Excel to Make a plot of temperature (°F) vs. time (s). On a single plot show all three sets of temperature data. On a second plot show power (W) vs. time (s). If you have not learned to make a plot in Excel please see https://www.youtube.com/watch?v=OVA2M7EIx80 – one of many videos available on YouTube that introduces this skill. Feel free to ask for help at Office Hours. For the report, a plot or graph is a figure. Figures have captions, not titles.
3.2 Describe briefly the trends you see in the four data channels collected (the three temperatures and the power). Describe these trends in terms of slope and linearity. Do these trends continue for the entire experiment time, or are there points of transition?
3.3 Create a hypothesis about the trend seen in the water temperature (T2). What do you think is happening? How would you analyze the experimental setup and the data to support your hypothesis? Consider such concepts or tools as ‘system boundaries’, ‘heat of vaporization’ (represented by the distance across a horizontal line in a T-v diagram), a ‘phase diagram’ (a T-P diagram), ‘transient’ vs. ‘steady state.’
3.4 Draw a sketch (by hand) or a schematic (with computer graphics) of the experimental setup used in the demonstration. One easy way to make a schematic is to use PowerPoint drawing tools, then cut and paste the result into your Lab Report. See the schematic in the ‘Sample Scientific Paper.’ Include an indication of the system boundary that allows the best thermodynamic analysis of your hypothesis. Is the system open or closed? What is the proper term to describe the type of system boundary you drew?
3.5 Extra credit (5 points) Does the highest temperature of the water indicated by the thermocouple during the experiment match the temperature you would expect for the boiling point of water in the lab? Explain you answer.
4. Conclusions: explain what has been performed, give the summary of results, mention the importance of this test.
5. References: provide all the sources you used to prepare this report.
6. Appendix (if necessary)
7. Be sure to consult the ‘Notes for Lab Reports’ on Canvas about technical writing issues.
Read the following ‘thought experiment’, discussed in class on Monday 2/8 and 2/15.
Important note – ‘Table B-1’ in the following is the same as Table A-2 in our textbook.
NOTE: Table B-1 in this article is the same as Table A-2 in our textbook.
In order to get full credit for Part 2, your lab report must contain one plot (item #1) and 12 short computations.
1) Figure 1 in this ‘thought experiment’ (see above) is a qualitative drawing. The goal of that qualitative drawing is to help students see that the given specific volume of water must be under the vapor dome because v is between vf and vg at both 20 °C and 100 °C.
Now, using EES, produce a T-v plot for water that is quantitatively correct. On it mark the points for State 1 and State 2. Use both the scale on the x-axis of the plot (specific volume) and the lines of constant quality to help locate the state points. Using the EES writing tool, place a mark at each state point. Near State 1 put a 1 surrounded by a box. Near State 2 put a 2 surrounded by a box.
Use ‘Snipping Tool’ or similar software to transfer the image of your completed plot to your Lab Report. Add a Figure number and caption.
Procedure for Part 2, Item #1:
Open a file in EES. In the Equations Window set a default unit system with the command $SI J Pa C mass deg. Click on ‘Plots’ and drop down to ‘Property Plot’. The Property Plot Information dialog box will appear (Figure 1.2).
From substances, select Water. From ‘Type’ select T-v.
On the lower left, delete all the pressures given and type in two entries, one for standard pressure (101325 Pa) and another for the pressure given in the ‘thought experiment’ at State 2. Note that the units must be in Pa, not kPa. Check the boxes next to the pressures you have entered so that these lines will appear on your plot. Uncheck the other pressure boxes.
Check ‘Show lines of constant quality.’
Uncheck ‘Include lines of s or h’. Click ok. The result should look like Figure 1.3.
Figure 1.2 – The Property Plot dialog box from EES. It is reached by clicking on Plots, and selecting Property Plot in the drop down menu.
Figure 1.3 – T-v Plot generated by EES. Notice that the choice of unit system in the Equations Window gives the units that appear on the plot axes.
Experiment with the plot. Left double-click on any number on the x-axis to reach a menu that allows you to modify maximum, minimum, grid lines, and other settings. Try the same on the y-axis. For example, I used this feature to reset the x-axis to have a maximum of 500 °C to better display the vapor dome.
To the right of the plot is the drawing palette. Check on ‘abc’ there to reach the dialog box that allows you to add text. Use that dialog box to add a 1 in a frame and a 2 in another frame. Once each number appears on the plot, drag it to it’s proper place.
Use the line command on the drawing palette. Left click on the line icon there, then left click on the plot where the line is to start and pull the mouse along to draw the line. The line can be dragged around the plot. Or right click on the line and use the drop down menu to format it to suit. Draw a line or arrow from each number to it’s approximate state point on the plot. On the drawing palette click on the red cross-hairs and mouse over the screen while reading the point locations on the bottom of the screen. That can help you to find the two State points that define State 1 and State 2.
Your results should look about like Figure 1.4. Feel free to select other styles or colors for text, lines, arrows.
Figure 1.4 – T-v plot for water generated by EES. The drawing palette has been used to add text and arrows. Clicking on features of the plot – axes, text, lines, arrows – opens dialog boxes for quick modification of plot features.
Part 2, items #2 – 13:
The Mason jar is a device invented in 1858 and used for home preservation of food. Today it is available at most grocery and hardware stores. It is a glass jar with a screw thread on top. The contents of the jar are heated to boiling, a flexible metal lid is screwed onto the jar, then the contents are allowed to cool, forming a vacuum seal that protects the contents from decay. The inventor, John Landis Mason, patented the device, but in the rough and tumble of business he was overwhelmed by imitators and died penniless in 1902. (If you would like to access the patent, with drawings and description, go to Google Patents and enter the patent number, US 22186.)
Giambattista della Porta’s thought experiment can be done with a Mason jar.
Use the following givens and process description, and answer the following questions. Use the thought experiment as your model. Show your computations and unit conversions. Number every equation.
Given: Mason jar volume: 240 cm3
Room temperature: 67 °F (according to room thermostat)
Ambient Pressure: 30.51 inHg (according to US Weather Service)
Some water is placed in the open Mason jar. The open Mason jar is held over the flame of a kitchen gas stove until the water is vigorously boiling. We may assume that the boiling water has driven all the air from the jar and that the jar contains only water. The jar is screwed closed. The jar is allowed to cool to room temperature. As the jar cools, the metal top of the jar moves visibly inward, so the pressure in the jar must be less than the ambient pressure. After an hour the jar is no longer warm to the touch and we may assume the contents of the jar are at room temperature. The jar is opened and the volume of the water is measured.
Water volume at room temperature when the jar is opened: 38 cm3.
Find the following information. Use Table A-2 in our Textbook. Answer in the units requested. Call the time when the Mason jar containing some boiling water is sealed State 1. Call the time when the jar has been cooled State 2. Consider the best format for your answer – a list? A table?
1) v1 (m3/kg) — Specific volume of water in the jar at when it was sealed (at its boiling temperature)
2) x1 — Quality of the water in the container at the time it was sealed
3) mg,1 (kg) — Mass of vapor in the container at the time it was sealed
4) mf,1 (kg)– Mass of liquid in the container at the time it was sealed
5) Volg.1 (m3)– Volume occupied by the vapor when the container was sealed
6) Volf,1 (m3)– Volume occupied by the liquid when the container was sealed.
7) P2 – Pressure in the container when it has cooled to room temperature. Even though the lid of the Mason jar is visibly pressed inward after cooling, model the Volume of the jar as constant.
8 through 12) x2, mg,2, mf,2, Volg,2, Volf,2 — use the same units as for State 1.
13) By hand sketch a qualitative T-v diagram showing State 1 and State 2 for the Mason jar. The result should resemble Figure 1 in the G. della Porta ‘Thought Experiment”. One way to do this would be to use a white board in Zoom, make the sketch there, then use Snipping Tool or a similar software to paste the result into your report. Remember to add a Figure number and caption.
Holding a Mason jar over a home gas stove is dangerous. Please don’t try it at home. It is easy to be burned, and the jar may break, with potential damage to skin and eyes.
Plastic jars such as 250 mL or 500 mL water or soda bottles are easier to handle, but will melt if heated to the boiling point of water. But a dramatic result can be seen by taking such a bottle, putting a little water in it, running it under hot tap water for two minutes, capping it, and letting it cool to room temperature. The moment it’s screw top is put onto it and it is removed from the hot water, the bottle immediately starts to contract, and continues to do so for a time.
But unlike with the thought experiment of della Porta, as the water is not brought to a vigorous boil, when the bottle is sealed, it contains liquid water, some water vapor, and air.
By considering properties of air and water, answer the following question: Is the contraction of this heated water bottle as it cools to room temperature caused primarily by a change in specific volume of the water – heated but not boiled – or of the air?
Open an EES file, set the units with the command $UnitSystem SI J Pa C mass deg. Practice using EES to call thermodynamic property information for water and for air.
To call for thermodynamic property information for a substance, in the EES Equations window click on Options and from the dropdown menu select Function Info. On the dialog box that appears select the button ‘Thermophysical Properties.’ On the next dialog box that appears select ‘Real Fluids.’ To solve Part 3, you will need to be able to call into your EES code property information about air and water. For a real fluid air (as opposed to an ideal gas) EES uses the name air_ha for air. Water is called water. The properties you will need to call from EES will be from among the ones used in Part 2 – Pressure, Temperature, quality, density, specific volume (called “volume” as a property function call).
Figure 1.5 – EES function information to call for the specific volume of air. The call can be pasted directly into your equations window, or you could write in the Equations window, for example, v_3 = volume(Air_ha, T = 38[C], P = P_3) or any other information in your program.
The function information dialog box reminds you of other combinations of two properties that can be used to fix this state:
Here are some sample function calls:
$UnitSystem SI C Pa J mass deg
T = converttemp(F, C, 67[F]) “room temperature”
P = 30[inHg] * convert(inHg, Pa) “ambient pressure”
X_1 = 0.28[dim] “quality of water, state 1”
V = volume(water, T= T, P=P) “specific volume, water, ambient conditions”
V = volume(water, x = x_1, T = T) “specific volume, water, ambient conditions”
V = volume(water, P = P, x = x_1) “specific volume, water, ambient conditions”
V_air = volume(air_ha, P = P, T=T) “specific volume, air, ambient conditions”
With this background about calling function information from EES, use EES as a reference to solve the problem.
Givens: A plastic water bottle labeled 500 mL volume was purchased from a grocery store. The bottle was opened and filled to the top with water. The water was poured into a measuring cup and measured to be 465 mL. This was repeated and verified.
Vol_bottle = 465 mL
The bottle was emptied. 50 mL of room temperature tap water was added to the bottle which was left open.
T_room = 68 °F (thermostat)
P_amb = 30.48 inHg (ambient pressure, US Weather service accessed online)
T_hot tap water = 150 °F (information on home water heater)
The kitchen tap hot water tap was opened. The open water bottle containing 50 mL of room temperature water, and air, was held under the flowing hot water in a manner so that no more water could get into it. The open water bottle was immersed in a larger jar with hot tap water running into the larger jar and around the water bottle. The water bottle was rotated in the larger jar and under the flowing hot tap water to provide even heating of the contents of the water bottle — water and air. After 120 seconds, with the water bottle still immersed in the larger jar of hot water, the screw top was placed on the water bottle. Its contents – 50 mL of water plus air – was sealed. The hot tap water was turned off. The closed water bottle was set on the kitchen counter at room temperature and allowed to cool for one hour.
The moment the bottle was set on the counter it began to shrink.
EXTRA CREDIT 5 POINTS – Do the procedure described up to this point yourself. Report your best measurements and estimates of initial bottle volume, room temperature and pressure, hot tap water temperature. Indicate how you determined/estimated your values for these items. Show a photograph of the bottle before immersion in hot tap water, and after it has shrunk.
State why you think the bottle shrunk.
NEXT STEP — The volume of the shrunken bottle was determined by displacement. A cylindrical pot larger than the water bottle was filled 2/3 with water. A ruler was clamped to the inside of the pot to measure the distance from the water surface to the top of the pot. This initial distance was set to 2 in. The inner diameter of the pot was measured. The shrunken water bottle, now at room temperature, was immersed in the pot and the rise in water level in the pot measured. The rise in pot water level together with knowing the inner diameter of the pot allowed determination of the volume of water displaced by the shrunken water bottle.
Vol_bottle_shrunken = 286 mL (volume of the sealed water bottle after cooling to room temperature).
EXTRA CREDIT 5 POINTS – perform this volume determination yourself. Show a photograph of your displacement/volume kitchen measurement device. Report the calculations to find the volume of water displaced by immersing the shrunken bottle. Discuss how this method might be improved with different types of immersion vessels.
Using the data given, or that you determined, and using property information from EES for water and air, and thinking about Part 2, state whether you think the shrinkage of the bottle was caused mainly by a change in specific volume of water or of air for the given conditions. Use words and numbers to support your answer.
Add any diagrams, photographs, or T-v or other plots that can help explain your conclusion.