Senior Honors Research Project Proposal

Design of Interactive Exhibits to Teach Fluid Dynamics Principles

at the

Carnegie Science Center

Patrick Walsh
Advisor: Susan Finger
May 4, 1995

Introduction

The Carnegie Science Center in Pittsburgh is an institution whose purpose is to promote awareness of the sciences, primarily focusing on inspiring science appreciation in pre-teenage youths. The Center often uses interactive exhibits to help students achieve intuitive understandings of scientific principles. The Center has asked Carnegie Mellon's Engineering Design Research Center to design several attractive exhibits that teach -- in an interactive, intuitive manner -- basic fluid dynamics principles. The project described in this proposal will be to design these exhibits, so that they may be constructed at the manufacturing facilities at the Carnegie Science Center and eventually put on display.

This report begins with a description of the history of the CSC's attempts to design fluid dynamics exhibits in the past, and their goals for the exhibits to be designed in this project. It continues with an explanation of the design process that will be used to achieve these goals. The report ends with scheduling and budgetary information.

Background

Two years ago, the Carnegie Science Center hired an engineering design firm focusing on water applications, to design several exhibits that encouraged learning about fluid dynamics. The exhibits were to be simple, fun, and able to attract the attention of the everyday twelve-year-old, while at the same time should carry with them lessons about fluid dynamics. The exhibits were to allow physical, visual, or some other interaction with the senses, and must be safe and durable for use by young children. The idea was to quickly grab the child's attention with a self-explanatory, fun exhibit which taught the child something about fluids.

The company delivered four exhibits to the Carnegie Science Center. (Incidentally, three of them were not working upon their arrival.) Two of these never worked and have since been dismantled, and two are currently on display in the center. Neither of these two satisfies all of the constraints in the paragraph above.

The first of the two remaining exhibits is essentially a smooth flow of water over a curved sheet of plastic in waterfall-type fashion, in an attempt to demonstrate the concept of laminar flow. At best, however, the child, upon seeing the exhibit, merely pokes a finger into the flow and watch flow patterns caused by his new obstruction. The nearby explanation of laminar flow on the wall is rarely read, and the exhibit fails in several respects, namely that it teaches almost nothing and is relatively non-interactive.

The second exhibit is more interactive and fun, but again fails to teach anything useful. It is a table which shoots out vertical jets of water upon which children can suspend balls. The table also randomly fires attractive laminar arcs of water out from one location on the table and into another. Certainly the children enjoy this exhibit, but little is learned about fluid dynamics.

Frustrated with their exhibits, the CSC turned to Carnegie Mellon for help in designing satisfactory exhibits. They first contacted Christina Amon, a professor of Mechanical Engineering here associated with the Engineering Design Research Center, and Professor Amon referred the CSC to Susan Finger of Civil and Environmental Engineering and the EDRC. In an attempt to improve the design of one of their prototypes, the Science Center came to CMU in March of this year and demonstrated their exhibit to various CIT faculty. In further discussions, it was decided that senior CMU students would, through the EDRC, design new displays to replace the current ones. The center requested that several displays be designed so that they could periodically rotate the exhibits and keep their displays from being stagnant.

This project, then, is to design several interactive exhibits that teach basic fluid dynamics concepts on a child's learning level. Based upon the above information, a list of design criterion for the exhibits can be created. The exhibits resulting from this project must ~ be interactive. Preferably the children will be able to touch, move, stand on, or otherwise physically interact with the exhibit; ~ teach something about fluid dynamics. The lesson should be basic enough to be understood by children as young as eight or nine years old, yet retain relevance and substance; ~ be self-explanatory to use. How to use the display should be obvious simply by looking at it. Children this age rarely have the attention span for written directions, so the directions should be implicit in the appearance of the exhibit; ~ be attractive and fun for children. These qualities are necessary to grab the child's attention and encourage the child to approach the exhibit, without which the exhibit would be useless; ~ fit into the space allotted by the CSC, both physically and aesthetically; ~ be safe. Chemicals, water cleanliness, and physical dangers are all safety considerations for an exhibit used by children; ~ be durable. The exhibit must be able to withstand abuse from countless energetic children; ~ be inexpensive to construct. The CSC used up a great deal of its budget on the displays, and has a minimized budget for construction of these displays; and, ~ be possible to construct in the manufacturing facilities at the CSC. Some possible fundamental fluid mechanics principles for the exhibit to focus on include hydrostatics, Archimedes' principle, hydraulic force converter, Bernoulli's principle and Venturi Tubes.

Some possible exhibit designs have, in fact, already been discussed. They include a hydraulic force converter, where children standing on one side of the converter could witness their ability to lift considerably more then their own weight (in terms of more children) on the other side of the converter. Another possibility is an improvement on the water table described above, this time using both air and water to suspend the balls -- offering a comparison between the two fluids.

At this point, it is important to note the possibility that the exhibits that the author of this proposal will be working on might not focus around fluid dynamics principles at all. This summer, several students will be working on this project at the EDRC, and depending upon their progress, the author's project will either continue their work with fluid dynamics, or perhaps he will begin designing projects which allow learning about other engineering concepts. In either case, the design process follows the same general outline, as described in the following paragraphs.

Methodology

This project is a group project and will be done with three or four other seniors from various engineering disciplines. Hence all of the following procedures will be team efforts or distributed efforts.

Designing these exhibits is a perfect example of an typical open-ended design problem, where the results must satisfy considerable requirements but whose end product is wholly unpredictable. As such, the project will be approached in a standard open-ended design fashion.

The first step in designing the exhibits is to decide on the fluid dynamics principles that the exhibits should teach their audience. The designers should also make sure they have an adequate understanding of these principles. Examples of several of these concepts are listed in the background section of this proposal.

The second step is the brainstorming step, where any and all exhibit ideas are brought to the surface and discussed. In an effort to encourage as many ideas as possible, no matter how seemingly silly, various brainstorming exercises or games could be used. These ideas would then be developed into concepts that could be, at the very least, visualized in simple sketches or described in understandable terms. A list of these ideas will be made.

During and after the brainstorming, the designers will check to make sure they have a solid understanding of what the goals they have for their design. These goals will be developed and probably will be similar to the requirements listed in the background section of this paper. This step, where what the designers want to see from the exhibit is finally fully established, is intentionally placed after brainstorming to ensure an open forum during brainstorming and prevent the constriction of possible ideas. This step may also include a trip to the Science Center in order to get a sense of what sort of exhibits are appropriate for the Center. Developing these goals may inspire some revision of the ideas created during brainstorming.

At this point, the list of possible exhibit designs will be submitted to the Carnegie Science Center for review. It is hoped that the list will contain perhaps as many as twenty ideas. The CSC will choose three or four of these ideas for further development by the design team and construction.

These chosen ideas will be developed into workable designs. This is the heart of the designing phase, and should be broken up into several steps. First, the exhibit designs should be developed to the point where they meet most of the project goals and most details of the designs have been specified. This initial design should work theoretically, or "on paper". The overall appearance of the exhibit is then contrived, where materials are chosen and size, shape and even color are given to the design. Once the appearance is worked out, actual mechanisms of the exhibit are decided upon. In this step, any pumps, piping, or any other technical support needed for the exhibit to function properly are designed or chosen.

Scale models may be created to aid in the design and the design-to-construction process. These scale models may be completely working models. It is expected that scale models will help bring to the surface flaws or weaknesses in the designs, and design revisions will result. Often it is impossible to see what part of a design will and will not work until a physical model is created. It is possible that high-technology design processes, such as chip deposition, will also be used in the design of the exhibits.

At this stage, the manufacturing capabilities of the CSC must be understood and accounted for. The designers must correspond with the Center to find an appropriate format (CAD, etc.) for submitting their designs -- a format that the CSC can use effectively in constructing the exhibits. Also, they must make sure that the Center has the sheer capabilities for constructing the exhibits they designed, and if it does not have these capabilities, appropriate redesign should be done.

Based upon the needs of the CSC's manufacturing facilities, final shop drawings and possibly scale models will be submitted to the Center for construction. This will complete the project. It is possible that some of the construction may take place at the facilities of the Civil and Environmental Engineering Department here at CMU.

Throughout this process, Carol Westin, the head of the exhibit design department for the Carnegie Science Center, will be available for questions and support.