Engineering Design Ice Cream Meltdown Alexandra Iuga Andrew Manning

Specifications and Constraints Create a way to keep ice cream cold Keep ice cream from melting for 20 minutes Constraints Limited materials Only 3 classes periods to complete work

Develop Knowledge Heat transfer Insulators and Conductors Where does energy come from? Where does it go? How does energy transfer? Insulators and Conductors

Brainstorming Use a cotton insulator in order to give a porous surface that can hold more air which has molecules that are less packed. Use a reflective shield on the outside of the contraption. We want to reflect as much of the heat as possible. >> How will these minimize heat transfer?

First solution Aluminum baking container Cotton balls Cup with ice cream inside

More brainstorming Create a big air cavity to distance the ice cream from the surface of the container and minimize thermal interactions. We need to utilize evaporation to remove heat from the system, using either the soaked Popsicle sticks or soaked felt. >> How will these minimize heat transfer?

First solution 2.0 Aluminum cover Aluminum baking container Cotton balls Wet felt Straws Cup with ice cream inside Wooden stick

Test and Reflect Reduce cost by using less materials Put in for 20 minutes at direct heat

More Brainstorming Soak the cotton in water. Chill the container that the ice cream is set in. More air cavities and lesson amount of aluminum foil. Less materials. >> How will these minimize heat transfer?

Second Solution

Test and Reflect This did not do as well We think it didn’t because: The felt got really hot Used too much aluminum Not enough air cavities Did not seal our container very well The water soaked into the felt turned into hot steam that melted the ice cream Too much surface area

Reflection and Lessons Learned Difficulties and Success Air cavities are effective at providing isolation The wet felt was a good idea in indirect heat, however there was no place for the warm gas to evaporate in direct heat. Consider points of contact Minimize the surface area Mass might not be a good indicator of whether or not the specifications were met, however a control provides strong evidence for the overall effectiveness of the design.