Greetings, naked scientists. I am wondering about alternatives to propellers for thrust production. What I have in mind is this:

The inspiration being a speaker cone, I get a square plate full with one-way valves (say, thin stripes covering the length of the square, all right next to each other. Or something.) and hook it up to a system that, similar to a speaker cone, vibrates it/ moves it back and forward. Now, if the valves open and close fast enough, it will be pushing air in one direction, producing some thrust, wouldnt it?

How much thrust could it make? Lets say, 1m^2 at 20Hz with the amplitude (that is, the total distance traveled by the plate in one sweep) of 2 cm? The air moved in one sweep would be 0.02m^3 and the mass of air would be 25.5 grams, according to WolframAlpha.

What would be the optimal frequency and amplitude before the plate or the valves just couldnt move that fast? And how much thrust would that give?

I did some simple calculations on my own, but I am not sure if they are correct:

I assumed the final air velocity would be the speed at which the plate moves, which is, in case of 20Hz and 2cm amplitude, 20*2=40 cm per second. Or is it twice as fast since it moves 20 times in one direction and 20 times back making it 40*2? I am not quite sure, but I want to know.

If the air is exiting the device 0.4m/s and it took just 1/20 (or is it 1/40) of a second to accelerate it to that speed, then the acceleration would be 8m/s/s (assuming the lower estimates).

Knowing acceleration and mass of the air pushed we get 8*0.0255=0.204 Newtons (or 204 grams?). But since its pushing only half of the time the total force decreases to 0.102 Newtons (?)

Not particularly much, using the lover estimates, it might be 2 or even 4 times as much as this, depending to answers to the questions above. But what if it revs up to 100Hz? Would the force be 5 times as much? 10 times as much? How much could the amplitude be increased? 4 cm?