Experiment 2 Lab Report

“QUEST FOR SPACE EXPERIMENT #2: NATURAL CONVECTION” TEAM INFORMATION School: High Tech High Chula Vista School Address: ​1945 Discovery Falls Dr, Chula Vista, CA 91915 Mentor Names: Ms. Meghan White and Ms. Kara Quinlan Team Members Roles and Names Project Manager/Documentarian: Katherine mara Astrophysicist: Meishelle-Grace Twano Mechanical Engineer: Luzcely Gonzalez Electrical Engineer: Alec Inda Computer Programmer: Austin Marquez

GROUP ROLES AND PROCEDURE

Project Manager/Documentarian: Katherine

My role for this experiment is to look over the other members and make sure they’re doing their work. If one of my teammates don’t have any work to do I assign them more work to maximize our time. I am also in charge of editing the videos that document all our work. Astrophysicist: Mei

My responsibility is to find all the research and science about the experiment. I look into different theories about natural convection, radiation, and other ways of heat and cooling transport that could affect our experiment and apply to it.

Mechanical Engineer: Luzcely

My procedure for this project is to build the humidity sensor. Within that, I needed to build the sensors and heating resistor in the experiment cube. I also needed to work with my partner, the electrical engineer Alec, so he can build the circuit board in order for the whole experiment to work. Electrical Engineer: Alec

My procedure is to wire the breadboarding, test if the breadboarding is working, and transfering power to the humidity sensor. Computer Programmer: Austin

My job is to write all the codes and run the experiment through the EV3, that records all the data and then transfers the data to a computer. Also, I have to put the data on a spreadsheet and make graphs to prove that we ran and recorded the experiment on the EV3.

PURPOSE The purpose of this project is to understand and learn about natural convection. In this experiment, we research and learn about convection circulation on Earth. We use these tests and experiments and prepare them to be sent up to the International Space Station, also known as the I.S.S, where they are going to use our instructions, videos, and photos to build this exact experiment in Space to test the differences between natural convection in Earth and in Space. This type to space research is important to know, because heat acts differently in microgravity, resulting in temperature differences. Therefore, heat and cooling have a different law in space to where they act differently from how they do on Earth, concluding on why this research is needed. RESEARCH: PART A Natural convection is a type of heat transport. Convection can be used on gas or liquid. The fluid (a gas or a liquid) is not generated by any external force, but due to density differences in fluid to temperature gradients (the rate of temperature changes in a certain area and it’s distance in between) .

Picture: writeopinions.com Hot air rises because when you heat air, the air expands and becomes less dense and the air around it; which causes the hot air the flow and rise up. But then, cool air is much more dense, but less dense than water. Resulting in the cold air to sink.

Picture: IG Infrared

Picture: Meishelle-Grace Twano The top sensor will heat up faster, because heat only rises on Earth. Overtime, the top sensor will still be the hottest, because the heat is coming from the middle of the cube and the heat is still only rising up to touch the top sensor. When air is heated its molecules move

around faster and the mass of the air takes up more space, which has a lower density and causes the heat to only rise up.

Picture: Meishelle-Grace Twano The bottom sensor will cool faster, because there is no direct heat transport going toward it. There is another way. Radiation is heat traveling in a form of light that can be visible and nonvisible. Heat radiation crosses between you and the spaces in between. If objects around you are warmer than you are, heat will travel more toward you. But, if you remove heat through ventilation, then it reduces the temperature in your surroundings and if your surroundings are cool than you are, your heat radiation will move toward objects, then absorb them.

Picture: Nuclear-Power.net

One sensor can heat up more than the other due to where the sensors and heat source are placed. Also, due to the reason I have explained before, convection is a type of transport for heat and heat only rises up. So an example would be, that if a heat source was placed in the middle of two sensors (one at the top and one at the bottom), the the top sensor will heat up first, because it has the first and most heat interaction.

Picture: Meishelle-Grace Twano In microgravity, the gases don't rise. They convert into a new process called molecule diffusion. The particles move from high concentration areas to low concentration areas or they mix together. As the heat temperature increases, the diffusion process moves more quickly and can cause the hot and cold molecules to mix more quickly.

Picture: science.nasa.gov

RESEARCH: PART B Some changes that we would add to our experiment is mount the resistor in a better position so that it has an equal distance between the two sensors. Also, the radiation coming from the resistor distorts the temperature readings from the two sensors and to fix this, we can add an acrylic wall barrier around the resistor and tape up the holes that are in the walls.

Picture: Meishelle-Grace Twano

Picture: Meishelle-Grace Twano The resistor is mounted in between the 2 sensors. Although, the resistor’s position is closer to the top sensor and farther from the bottom. Resulting in the heat coming from the resistor will move faster toward the top sensor. The resistor is attached to the mountain plate and if we shorten the metal peg holding it up, then we can even out the distance between the resistor and the top and bottom sensors.

Picture: Meishelle-Grace Twano The resistor is the source of heat. So, if the resistor has a farther distance from the top and bottom sensors, it will take a longer amount of time for the resistors heat to reach the sensors. Therefore, if you want your sensors to heat up faster, then it is better if the resistor is closer and not farther.

Picture: Meishelle-Grace Twano

Picture: Meishelle-Grace Twano

In the experiment cube, the heat coming out of the resistor is getting mixed with the air around it. So, in order to stop the air from mixing in, you can add acrylic walls around it and tape off the holes that are inside it. By adding these walls, it’s going to act as a barrier from the air, but still allowing the heat to escape the walls and touch the sensors.

Picture: Meishelle-Grace Twano Both of our 2 sensors are the same. But, the position of them are different. One sensor is located and the top of the experiment cube and the other is located at the bottom. Then, the resistor which produces the heat for the experiment is located in the middle of the experiment cube between the 2 sensors. Now, if we change the positions of the 2 resistors, all of our data will be different. Depending on where the resistor or sensors are placed, then the heat and timing will differ between sensors. GROUP HYPOTHESIS -KatherineClosed - Top sensor: 90 degrees fahrenheit. Bottom sensor: 60 degree fahrenheit I think the top sensor will not only heat up faster but also heat up more over time because first of all, heat rises. Second, it would heat up more because it would heat up the fastest. So the top sensor would be already heated up making it heat up more over time. Since, it had a head start.

Open: Top sensor - 80 degrees fahrenheit. Bottom sensor - 55 degree fahrenheit I think that having it open wouldn’t drastically change the results. I believe that everything would just heat up slower. -MeiClosed - Top senor: 75 degrees fahrenheit Bottom sensor: 68 degrees fahrenheit I infer that the top sensor will heat up faster and still have a higher temperature rate overtime, because heat only rises up. Although, overtime the bottom sensors temperature will start to rise, due to the convection and a circulation of heat throughout the whole experiment cube, but will never pass the heat temperature of the top sensor. Open - Top sensor: 80 degrees fahrenheit Bottom sensor: 52 degrees fahrenheit I infer that when the experiment cube is open, the top sensor will still heat up faster. I also infer that overtime the bottom sensor will not rise in temperature, because the heat the will rise up and touch the top sensor will then exit out of the cube. Therefore, the heat will not circulate throughout the cube. -LuzcelyClosed - Top sensors: 90 degrees fahrenheit Bottom sensor: 74 degrees fahrenheit I believe that when the experiment cube is closed the top sensor will heat up quickly with a great amount because heat rises. And because the cube is closed the heat doesn’t escape, it will stay in the cube heating the sensor that’s on the top. Open - Top sensor: 83 degrees fahrenheit Bottom sensor: 67 degrees fahrenheit I believe that the top sensor will heat up more and quickly. I believe this is true because if heat rises to will potentially heat the top sensor, then it will escape from the experiment cube. So therefor the bottom one will stay cool, but because the walls will be open, the bottom sensors will most likely be in room temperature like around 68 degrees. -AlecClosed - Top sensor: 81 degrees fahrenheit Bottom: 69 degrees fahrenheit My hypothesis for when the box is closed is that the top will heat up faster because heat rises so there will be more heat on the top censor.When the box is opened, I believe that the bottom because there will be less heat on the bottom censor. Open - Top: 78 degrees fahrenheit Bottom: 67 degrees fahrenheit I believe that the top one will still be hotter because even though it will be open heat would still rise and the top censor would still be hotter.

-AustinClosed - Top: 95 degrees fahrenheit Bottom: 84 degrees fahrenheit Open - Top: 85 degrees fahrenheit Bottom: 78 degrees fahrenheit I believe that the top sensor is still going to be hotter than the bottom sensor, because all of the heat is going to escape from the open parts and the open sides so it will not heat up as much.. I believe that the top sensor is going to be hotter than the bottom, because it is going to be more isolated; also because there is going to be way more heat and it is going to end up circulating all inside the experiment box and therefore it will get hotter faster.

Overall Hypothesis (Earth): As a group we infer that the top sensor will be hotter than the bottom sensor, because heat rises. We also believe that the open box will be cooler than the closed box because the air will not confined to a certain space. We believe that the closed box will be hotter because it would be circulating the same air for three minutes. Overall Hypothesis (Microgravity): As a group we believe that in microgravity that the top sensor will also be hotter than the bottom sensor, because heat rises since denser air (colder air) goes down. Since convection relies on gravity for heat transfer to occur, we believe that everything will happen more slowly in microgravity than on Earth. HARDWARE DESCRIPTION Description of the electrical circuit: The first step to breadboarding was getting the paper with the instructions so that I know what to wire. After that I connected the positive to 5v and the negative to gnd. Then I wired to resistors to reduce current flow. After that I plugged a male to female wire in the relay switch. For the mechanical part of the experiment, the first thing to do is to take the tools and elements that you will need for this experiment. Then start disassembling the experiment cube and take everything out of it. In the Quest for Space packet that was given, there was specific instructions in how to build the experiment cube (if interested in knowing the steps, go to Mechanical Model on page 20). After following the instructions, the electrical engineer, computer scientist, and the documentarian need to run seven experiments. The experiments needed to be tested to see its volts, having the experiment cubes open, closed, and taped. If having some troubleshooting, try again and find out what you did wrong. If not, then congratulations your job is done!

SOFTWARE FLOWCHART

VARIABLES Independent Variables Independent variables are individual things that stand alone, they don’t need other things to be able to work. - (+) wires - (-) wires Wires do not need anything else to be a wire. - Time Time keeps running regardless of anything that happens. - Breadboard The breadboard is still a breadboard regardless of anything. - Power source The power source does not change. The process of making power doesn’t rely on anything else to make power. - Battery The battery does not rely on anything to store and supply power. - Sensors

The sensors work on their own to sense heat. Dependent Variables: Dependent variables are variables that are also individual things, except they don’t stand alone. They need to rely on another variable to be able to work. - Current Current relies on resistance and voltage. - Resistors Resistors rely on current and voltage. - Voltage Voltage relies on current and resistance.

MECHANICAL MODELS

In order to build the experiment cube there are specific steps to understand what exactly you're supposed to do:

Step #1: Remove all the parts from the “Quest for Space” box that you will need for this experiment. Step #2: Take apart the experiment cube and everything inside of it. Step #3: Take the bottom plate which is made out of aluminum. Step #4: Take the two FatCat temperature sensors and attach sensor #1 (facing up) in holes 1 and 2 on the top side of the bottom aluminum panel. Step #5: Then attach sensors #2 (facing down) in holes 11 and 12 of the underside of the top acrylic panel. Step #6: Now mount the heating element, the ceramic resistor in the middle of the cube between the sensor. Use the acrylic mounting plate on 1 inch standoffs in holes 11 and 12 on the bottom panel with a pair of nylon hex nuts. Step #7: Connect two breadboard jumper wires that are red and black to the ceramic resistors. Feed the wires through the rear slot in the right panel. Step #8: Connect the sensors to two custom RJ12 Lego cables in preparation for connecting to the EV3 brick. Step #9: Feed the cables through the right middle slots in the top and bottom panels. Step #10: Screw on the cube walls and top panels Step #11: Now for your final step is to test the relay switch circuit and the EV3 code.

ELECTRICAL MODELS

The first step to breadboarding was getting the paper with the instructions so that I know what to wire. After that I connected the positive to 5v and the negative to gnd. Then I wired to resistors to reduce current flow. After that I plugged a male to female wire in the relay switch.

TROUBLESHOOTING STEPS When testing our circuit board we did seven tests to make sure everything is okay. Pretty much Alec used an ammeter and tested all the components of the bread board and made sure that the current and voltage was the amount we wanted. Everything was successful while testing the bread board on the first try. So we moved on to running the experiment. While running the experiment we noticed a problem. The numbers that the EV3 was giving us was a little suspicious. We eventually figured out that some part of the code was running a certain loop infinitely which is what caused the problem. We then fixed that and carried on with the experiment. After that we found another flaw in the our experiment. We, however, didn’t find it until eight hours before the experiment was due. It was tightened too much so the acrylic started melting, making the sensors not be able to sense anything very well.

GROUND DATA TEST RESULTS -Closed (No Tape)-

-Closed (With Tape)-

-Open-

EXPECTED RESULTS AND CONCLUSIONS As a result from all of our experiments, the top sensor was overall and high temperature than the bottom. In different testing conditions, the top sensor grew dramatically hotter, or the two temperatures were very close. As a group, we predicted that in space and microgravity, the top and bottom sensor will be at the same temperature rate. We infer this, because heat does not rise in space due to the lack of air causing it to become less dense. Therefore, we believe that the temperature of the sensors of Earth, will be completely different in space. PHOTOS

Picture: Katherine Mara

Final Product

Open (Top left), Taped (Top right), and Closed (Below)

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