imagine a capacitor.
one half of the capacitor,
is 6 inches long, by 6 inches wide.
the other half of the capacitor,
is 3 inches long, by 3 inches wide.
the capacitor is charged with 20,000 volts,
at a few milliamps.
similar to what a tesla coil puts out.
there is electro-thrust, towards the 6 inch side.
and away from the 3 inch side.
because for whatever reason,
there is thrust towards a stronger magnetic charge,
and away from a weaker magnetic charge.
it does not matter which plate is positively charged,
and which plate is negative charged.
there is always thrust, towards the larger plate/charge.
so it is NOT ionic wind.
the surface area of the metal,
seems to determine the maximum charge,
more than metal thickness.
so for this capacitor,
a wide,
flat,
saucer shape,
would work best.
if you want a demonstration,
than look at "beamships" on youtube.
their devices work, because one polarity,
is charged stronger,
than the other polarity.
if they used the saucer shape,
than their devices would be much more efficent.