Make a Whistle & Be a “Whistle Blower”

####Make a Whistle and Be a “Whistle Blower”

#####This is a STEM education project. The goal is to explore the whistle mechanism (edge tone) instead of making a lifelike whistle.

The whistle seems to be a simple yet complex design project. Mathematically it is simply made up of a cylinder and a rectangle box, with an opening and, perhaps, a ball inside. The challenge is: How can one design a whistle that actually makes some sound or even works in the way expected?

It proves to be a messy process. Imagine it, design it, and print it out. Most probably, it won’t work as expected. That is why this stands as an inquiry lesson in a STEM class.

A few years ago, I tried it and designed a few whistles that did not quite work. Recently, I decided to take on the idea again, encouraged by the ideas of a group of students. Below is a summary of my efforts. Of course, there are always other ways to approach this STEM project.

####Summary of My Efforts.
1. Without checking any reference, I imagined a whistle as, I think, I know, and made a sketch in terms of its measurements and basic structure.
2. I tried an opening of random width( about 2.5mm) and played with the position of the edge/blade.
3. I realized that the width opening matters! Then, I made a few whistles with various width from 10mm to 4mm. They all work! For me, the 4mm version sounds the best.
4. I did some search and found a page about “edge tone” (see reference)
5. I decided to make a whistle with adjustable opening.
6. The game is not over yet; more to think about when I have time.

Among the Files

1. A whistle with a long neck and two versions of a slider for opening adjustment. ** I manipulated the neck so it can be printed without support**
2. Six whistles of specific opening widths, ranging from 2mm to 16mm. The 2mm version does not quite work.

Reference

1. http://hyperphysics.phy-astr.gsu.edu/hbase/Music/edge.html