The Carnegie Science Center asked students working at EDRC for the summer to help them design an exhibit that demonstrated a popular concept of fluid mechanics. Our main objective was to design a working prototype of an exhibit demonstrating fluid mechanics. The main constituents concerning this project was that it had to appeal mainly to children between the ages of 8-15 and allow them to interact with it. Throughout the summer, a group of seven students (Justin O Parkhurst, Han Cho, Zen Osang, Anne Bielke, Edgardo Torres, Iris Leon, and Tonya Rado) experienced with different design concepts under the direction of Civil Engineering professor Susan Finger and Mechanical Engineering professor Cristina Amon, and Noreen and Carol Weston of the Carnegie Science Center.
To get a better understanding of the concepts involved, the group first did some individual research and then met for a group discussion. Justin researched basic fluid mechanics principles in the EIT Reference Manual and jotted down ideas which triggered our first brainstorming process. Edgardo and Anne researched basic child development concepts to better understand the age range that our exhibits had to appeal to. Their main concern was how children learn. Zen also researched child development and concentrated on ways to motivate children in our target age range. During that time, Professor Finger suggested that we speak with someone from the Center for Innovation in Learning. Anne also met with Molly Johnson who gave her a list of relevant resources. They also concentrated on the research findings of Jean Piaget, one of the primary founder's of child psychology/development. Then they constructed an outline (see Appendix A).
In summary of this outline, Piaget was a very significant figure for his discoveries of a child's cognitive processes, we thought that a brief summary of his "stages" of learning would be helpful in understanding what a child is capable of learning at various age levels. The first two parts of this section are just a brief summary of how toddlers learn and what motor functions they possess. The last two sections, however, are the most relevant to our project.
In terms of delivery of instruction, the books we found discussed how to instruct children in the classroom. We extracted the information that seemed to be most relevant to teaching a concept through experiments/exhibits and found that there are two different types of instruction-direct vs. discovery. Direct basically deals with classroom lectures or readings. Discovery is more along the lines of experimentation/science labs. In the discovery section, it is important to note the pros and cons. For instance, one of the problems the Science Center has with its current exhibit is that, although it's fun to play with and aesthetically pleasing, children didn't seem to get much out of it educationally.
The next part of the outline discusses some pointers on how to change previous intuitions a child might have. Both Edgardo and Anne discovered that a child might come to a conclusion about why something happens, but his/her conclusion may be incorrect. This result is especially common in younger children between the ages of 6-9 years old. An example of this appeared in the book entitled, Beyond Modularity, a group of children, ages 4-10, were asked about what would happen if a heavy object such as a book was placed on top of a lighter one. The results of this experiment indicated that they understood the heavier book would exert some type of force on the lighter one and therefore, the lighter book would have some sort of observable effects such as deformation. However, when the same group was asked to answer what would happen if the book was placed on the desk, they still thought that some sort of observable effect had to occur.
Section C basically says it's useful to have concrete materials as well as something the children can interact with in trying to teach a new concept. Once again, one doesn't want the child to do that to the point where he/she may become frustrated or lose the concept somewhere alone the lines of completing the task.
Finally, we considered relating a new concept to something that the child may have already been familiar with. For example, helium is lighter than air, that's why a balloon will float. They know what air is and they probably know what a balloon looks like and that knowledge helps them to understand the concept a little better.
Zen researched most of the motivational aspects in the outline which basically focuses on how to motivate a child to learn. When designing the exhibits, it is important to remember that a child must want to interact with it and to learn from it at their own pace.
Basically there are two types of motivation intrinsic and extrinsic motivation. Intrinsic motivation includes how a person feels when he/she accomplishes something on his/her own. Extrinsic motivation is more materialistic or is based primarily on achieving a goal in order to gain a tangible reward. Both of these are important in the design of the exhibit.
Part B of the outline on child development elaborates on intrinsic motivation as it is broken down into four parts. a psychologist named Berlyne classified motivation in terms of the "qualities of interesting events." This included novelty, uncertainty, conflict and complexity. Berlyne believes that a person's behavior of exploration or curiosity occurs because of his/her desire to resolve a conceptual conflict and that interesting event contains at least two of the four mentioned characteristics.
In the beginning of our group brainstorming session, our ideas were very general (viscosity, sound and light change, etc.) and soon became more specific such as the evaporation tank concept. Brainstorming techniques helped us to better understand our problem statement. We tried not to censor ideas but rather to explore each idea. This led to a wide range of realistic and functional ideas with which to experiment. Next we made thumbnail sketches of our better ideas. This helped us to understand the problem from a visual standpoint. Visuals also enabled us to convey our ideas more effectively to others. Then we researched our favorite ideas. We discovered that brainstorming dramatically improved our thought processes.
We arranged our ideas into principles and applications (see Appendix B), and then we explored different ways that these principles could be demonstrated visually in certain applications (see Appendix C). Then we made a list of our final ideas and researched basic concepts relating to each of them. These exhibit ideas are as follows:
We presented our list of ideas to the Carnegie Science Center and they chose six that they wanted us to further experiment with. These ideas were as follows: hydraulic ram, circulatory system, compressibility box, buoyancy/ stability, natural water systems (volcano and sand dunes), and sound propagation.
Throughout our planning process, we tried not to ever lose sight of our goals which were to have the exhibit be interactive, educational, durable, self-explanatory, cooperative, interesting, and the appropriate level of difficulty.
We met with the Carnegie Science Center again and Carol encouraged us to think of possible second floor designs and also to explore potential "Rube Goldberg" concepts. She also gave us a water table that had been designed for the Carnegie Science Center, but did not function properly. Since that was also one of our design ideas, we tried to figure out why it had failed. We discovered that water did not enter the table as laminar flow, but rather as turbulent, thus causing the flow over the objects inside the table to be incorrect. We also noticed that the particles the Science Center had used did not illustrate the flow accurately as expected. The particles did not reflect well. In addition, the objects inside the table could not have been able to be moved around using the magnet provided. Thus, this design concept proved to have many flaws.
Anne researched methods to make the water flow entering the tank more laminar. Most of her information came from Professor Fran McMichaels. Since water was entering the table from a half-inch diameter pipe into a larger opening, McMichaels suggested using some type of screen system or vents to make the flow more laminar. The screen system he explained was basically a set of screens which when positioned in a pipe, the laminar flow would increase. He also suggested that it would be best to start out with a screen that had large holes and narrow that down to one having smaller holes. The vents, he said, would be useful when trying to keep the flow laminar when it passed thorough a bend in a pipe, and we are trying to apply a similar technique to our water table.
Then we visited the Carnegie Science Center to measure the space allocated for our exhibit and to get a better sense of how our exhibit would fit in with the others. We also conducted another brainstorming session to further explore our six ideas. Then we researched how sound travels in various fluids. Once we examined our results (see Appendix D), we discovered that the ideal gases to use were oxygen, carbon dioxide, and hydrogen.
From then on to the present, we have been exploring ways to prototype our ideas to test our concepts. Thus far, we have explored many techniques using the water table which was designed to show a 2-D view of fluid flow. Water flowing through the table will be recycled using a water pump. We also experimented with different tracers in various states (liquid, gas, and solid). For instance, we found that liquid tracers require a special ducting for dispensing the tracer. Also, both the flow of water and the flow of the liquid tracer must be kept laminar. Since water will be recycled, the liquid tracers need to be separated from the water in order to reuse it.
We also tested gas tracers and found that they have a tendency to rise due to buoyancy. Gas tracers also require different technique to create bubbles and the "hydrogen bubble" technique seemed to be the most promising. However, the particles of solid tracers are suspended in water because their density is equal to water (1.0g/cm3). We also discovered that solid particles sink down due to gravity and the must be insoluble in water. Solid particles also have to be very small to fully represent the fluid and larger particles have problems maintaining the fluid flow. The solid tracers that we found to be the most successful to illustrate fluid flow are pliolite, polystyrene, and aluminum flakes (see Appendix E). Edgardo is constructing a system to make the water flowing into the table more laminar.