Karlie presenting her “Thermal Carousel” Project at the Science Fair!

I am super proud of Karlie for all the energy and time she put into her Science Fair Project.  She spent evenings and weekends working on her project for several weeks.  There were times when it wasn’t as excited to work on the science project, like with all the science journal writing, however, she buckled down and got it done.  All her hard paid off because she also was picked as one of the top 2 for her class!!!  Karlie got a 100% on her science experiment journal and 100% on her science experiment presentation!  Way to go KARLIE!  So proud of my girls and their hard work!

All the science projects had to be submitted to the teachers at the end of April so that the teachers would have time to grade all of them prior to the actual science fair.  The science fair was later in May so the whole project expanding over a couple of months.  Karlie had a lot of fun doing the actual science experiment.  The display board and the presentation of her project was something she enjoyed too.  Like her sister, Karlie’s least favorite piece of the experiment was all the hand written information for her journal.  Karlie had over a 100 pages of hand written information regarding her science projects and procedures.  We video taped her doing the experiment trials and have over 2 hours of her doing her testing.  She will probably enjoy going back and watching it again someday in the future!

This is an experiment that you may enjoy replicating.  I have included a shortened version (remember her hand written notes were over 100 pages) of her science project and procedures she used to go through the experiment.  Some of the information such as her title, purpose, hypothesis, and experiment are directly below.  Additional information such as her constants, variables, research, materials, step-by-step procdures, analysis, conclusion, future work, and more are at the very bottom after the pictures.  Have fun doing the experiment!

Karlie titled her science experiment: Thermal Carousel

Purpose:

• Does hot air expand and rise?
• Would changing the temperature affect how fast the fan wheel spins?

Hypothesis:

• If candles heat air, then the air will rise, turning the fan.

Experiment:

• Build a thermal carousel windmill that will spin when a certain number of tealight candles are lit under it.

Karlie sharing her project with another student.

Karlie listening to their questions!

Karlie sharing her Science Fair project with Mrs. Johnson, her last year’s homeroom teacher.  Mrs. Johnson was super sweet and stopped by to talk with both girls about their projects.

Karlie’s presentation board and displays at the Science Fair.

Karlie had several display items to show people as they came by her area.

Timing the fan for one minute while counting the number of times it spun.  She was completely focused.

The thermal carousel starting to spin.  Notice the tiny light pink piece of paper on one of the fan blades.  That was her marker so she could keep track of her how many rotations the fan blade spun.

Counting!  The blue straws helped her see when the rotation was complete.

Checking the stop watch.

Testing with 2 candles lit

Work in progress on her display board.  The majority of her information is complete now to figure out which pictures she wants to add to her board.  The yellow sticky notes are where she plans to add more pictures.

She decorated her thermal carousel!

Very colorful and fun!

Karlie’s rainbow thermal carousel!

Thermal Carousel Science Project Journal

 Karlie decorated her Science Project Journal Notebook with duck tape.  This is the back of her journal.  She was very excited to get it completed!

The information below contains more about the experiment so you may try it for yourself.  It was a neat project.  Karlie put in a lot of time to get everything completed and her hard work paid off.  It was a great learning experience for her too!

 Manipulated Variable:

• I will change the temperature of the air by increasing the number of candles under the fan blades.

 Responding Variable:

• The movement and speed of the rising air is measured by tracking the speed of the spinning fan blades above the heat source.
• I will count the number of full rotations per minute (rpm) in each trial and record the data.

 Constant:

• The room temperature of the air will remain the same throughout all trials of the experiment.
• The distance of the fan blades from the heat source will remain the same during the experiment.
• The friction of the fan on its axle will remain the same.

 Research:

The first thing we must understand is that heat is a form of energy.  As the air absorbs energy from the heat it makes the molecules start to move more, expand, and decrease the air density.  With the same volume of air the hot air will not only weigh less it also has fewer molecules.

Hot air is always in motion.  As the air increases in temperature the molecules become more active by vibrating, bumping into each other, and expanding to fill the space between each molecule.  The Laws of Thermodynamics explains the relationship between the volume of air and its temperature.  As air gets hotter it produced more kinetic energy which is transferred to the air molecules.  The particles from the warm air rising should cause a fan or spinning object to increase in speed.

Air is full of a mixture of gases.  The majority of gases in air are nitrogen and oxygen.  Gases weigh different amounts and will change as you add a heat source.  When the warmer air rises it pushes, vibrates, and begins moving.  Force could be described as something that pushes on something else.  As the hot air rises it will hit the fan blades thus they start moving sideways which is called lift.

Analysis:

I completed 5 full trial experiments using a various number of lighted tealight candles under the carousel fan blades.  Based off the information I collected from the trials I was able to create graphs.  The data indicates that heat does rise, expand, and have an effect on fan blades that are sitting directly above it. 

 Conclusion:

The experiment appeared to work well and support my hypothesis that when candles heat the air, the air will expand, rise, and cause the fan blades to turn.  It was neat to see this work and be able to chart the results.  There is a lot more I could do with this experiment to learn more regarding this topic. 

Future Work & Questions to Ponder:

• Did the distance between my candle flames and carousel windmill fan blades affect the speed and number of full rotation per minute?  To find out the answer to this question I could repeat the science experiment, but shorten the length of the skewer? What would happen if it were longer?
• Did I alter any of the experiment trials by being physically near the experiment?  Would my breathing, a sigh, sneeze, leaning on the counter, bumping something nearby, or anything similar potentially change the movement of the air around the experiment and altered the data collected?
•  Would changing the angles of the blades from 30 to 40 degrees (or another amount) affect the speed of the blades?
• Will the position of the candles change the speed of the blades?  What if they are not evenly spaced or I changed their outer positions?  Moved them closer to the center of the pie pan stand?  How will these changes affect the speed of the fan?
• By adding a little friction to the parts would that make it better or worse?  I believe any additional friction would cut down on the blade speed and possibly even stop it from spinning.
• Would using different candles have any impact?  By changing the height, diameter, brand, scented, unscented, and more cause any changes in speed of the blades?
• What would happen if I redesigned the base or fan blades?  Are there ones that would be faster?  Is there an ideal shape to get the most rotations per minute?