Robyn Gottheiner

January 23, 1998

As a senior at Palo Alto High School, I had the option of taking a class called Science Research. This class places students with a mentor who works in a field that interests the student. I chose to study at NASA with Susan Lee who works on the Aerospace Team Online Web Site.

One opportunity Susan provided me with was to visit with Mina Cappuccio. Mina deals with models of high speed planes, and she tests them in the wind tunnels.

My visit with Mina turned into an amazing educational experience. Not only did I learn about such terms as Reynolds number and what functions each wind tunnel specializes in, but I got the chance to see two of the many wind tunnels at Ames!

The wind tunnels at NASA have always intrigued me. As a child I would always stare at the huge building with amazement as I passed by on Highway 101. I would fantasize about what went on inside these wind tunnels. I pictured researchers in big space suits calculating information as they watched some mind-blowing spectacle.

Well, to tell you the truth, I wasn't too far off (except for the space suits!). As we entered the 11 by 11 foot Transonic Wind Tunnel, Mina unlocked the safety door that leads to the main floor. (Transonic means that the air inside the tunnel can travel at speeds that range from high subsonic to low supersonic speeds.) The huge room had a large cylinder-shaped object that stretched the whole length of the room. Mina explained that the tunnel went in a circular shape, and that we were only looking at a small portion of the wind tunnel. I didn't understand why this huge facility was called "11- by 11-foot." But quickly, it was brought to my attention that this dimension referred to the height and width of the tunnel where the model is placed (this piece of the tunnel is called the "test section"). So, basically, the model of the airplane that they are testing has to fit in an 11- by 11-foot area.

The reason they chose this dimension for this Transonic Wind Tunnel is so the researchers can study the model at Mach numbers between 0.4 -1.5, at a Reynolds number of 1.26 -9.4 x 10⁶ per foot. I learned that each wind tunnel specializes in different Mach and Reynolds number ranges, densities, pressures, forces, and many other conditions. So, the model is placed in a sturdy holder that is downstream from the model (this is so the holder doesn't interfere with the airflow around the model). The standing air is pushed through the circuit using a very large compressor with the model in the test section of the circuit.

The researchers sit in a room near by, where they watch the model on many video screens and calculate really important information for improving the plane (or whatever the company is building). It is necessary for the technicians and researchers to be in a separate room because of safety precautions. If there was a crack or mishap in the tunnel, people could potentially be sucked into the wind tunnel. This is why these tests in the wind tunnel tend to be limited to people involved in each experiment.

After seeing the 11- by 11-foot Transonic Wind Tunnel, Mina took me to see the 9- by 7-foot Supersonic Wind Tunnel (supersonic means that the air travels at speeds faster than sound). The area the model sits in this tunnel is obviously much smaller than the previous tunnel. This wind tunnel also deals with higher Mach numbers, lower Reynolds numbers, a different range of pressures, and many other conditions. Mina explained that this, as well as other wind tunnels in the NASA facility, were temporarily out of use because they were being equipped with high tech computers for data, and the actual tunnels were being repaired, too. She said that they were originally built in the 1950s and that NASA hoped to reopen these wind tunnels for tests within the next few years.

Because the wind tunnels are being repaired, this means that Mina and other researchers have to travel to other places to test in wind tunnels. I was surprised to learn that there are tons of other wind tunnels all throughout the country. But, the biggest in the world is right at NASA Ames in Mountain View!

Even though I didn't visit the biggest wind tunnel, I still feel privileged to have had the opportunity of seeing two smaller tunnels. I learned a huge amount about the purpose of wind tunnels and how they help technology. I hope that I have been able to relay some of the exciting and educational information that I encountered in this adventure.

As I continue to work with NASA until the end of the school year, I am learning one really big lesson. The basics that students are taught in school, like physics and math, are the keys to all the interesting technological work at NASA and all over the world. I have been able to value what I learn in school, because I know almost all the theories and calculations will be applied in whatever I do later in life.