The Wind Tunnel (Page 2)

We scheduled a meeting for the next week at NASA Ames Research Center near Mountain View, CA. Rabi introduced the team to Greg Zilliac. Greg is also an aeronautical engineer and manages and operates the tunnel we would use. The team discussed what speed the tunnel could be operated and how to mount the ball into the tunnel. We also talked about how we might spin the ball in the tunnel.

Jani had seen researchers spin golf balls in wind tunnels using wires. Rabi had used a ramp to spin a cricket ball. As the ball rolls down the ramp its spin rate increases. The spin rate in tennis was much faster than a cricket ball. For safety reasons we would have to firmly secure the tennis ball inside the tunnel.

We were concerned about spinning a regular tennis ball in the wind tunnel. First, the spin rate is high - how would we accomplish this? Second, a standard tennis ball is only about 2 1/2 inches. If we mounted the tennis ball with a thick metal rod through it we feared that the rod would actually interfere with the aerodynamics of the tennis ball.