Fluid Dynamics trick

These pieces allow you to demonstrate aerodynamic suction with blowing air.

The top disk should fit snug into a standard adapter for an air mattress pump, depending on your tolerances.

After you have the pump turned on with air blowing, slowly bring the lower disk toward the upper disk. You will feel the force of the air jet pushing the disk away until you get close to the other, when suddenly, the air will suck the two disks together. The air is still blowing and there will be a small gap on the order of 1 mm between the two plates. With some non-trivial math, you can calculate the expected gap width or the maximum force of the aerodynamic suction.

I have two sets of disks - large and small. Either will work. The cones on the centers of the lower disks are provided to direct the air jet and prevent it from sliding.

You will need an air pump and air mattress adapter (or print a custom adapter).