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Let suppose the following body:

enter image description here

  • blue is electrically charged positively,
  • red is electrically charged negatively,
  • yellow is an insulator.

I would like to understand the effect of the electrostatic force if this body is moving through a gas (in the direction of the thin edge).

enter image description here

In particular, I would expect a ionizing arc charging particle close enough of the body.

enter image description here

  • Those particles would be repelled and move away?
  • If this happens, would it reduce the pressure of the gas flowing against the shape?
  • And finally, is this reduction of pressure going to be relevant?

Although this is a very specific example, I am interested in the principle more than the specific case. The example can be used to answer the question, but any other arbitrary shape would be acceptable.

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I would guess that if you could keep the charges (like an electret perhaps) and the field lines are right and the gas is ionized, that the answer to "If this happens, would it reduce the pressure of the gas flowing against the shape?" is no. It will still take the same amount of work, force times distance, to move the gas aside. Maybe you can avoid some friction heating and you still get the more serious compression heating.

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  • $\begingroup$ "It will still take the same amount of work, force times distance, to move the gas aside." That is not the question, the question is if some of this work would be performed by the electric field, and in case, at a different distance/place than standard sonic shock. For keeping the charges, I guess a generator would work. $\endgroup$ Jun 9, 2018 at 11:00
  • $\begingroup$ The question I am addressing, which I quote in the answer is "If this happens, would it reduce the pressure of the gas flowing against the shape?" I failed to point out the link between the work done to move the gases and the pressure, so one could miss the implication that this does not do anything to the pressure. $\endgroup$ Jun 10, 2018 at 3:38
  • $\begingroup$ So you are stating a ionized gas in presence of an electric field is not affected, and thus rejecting my first statement "particles would be repelled". Don't you see? your answer is pure aerodynamic and forget all the electric part of the problem; probably you are right in the result, but the explanation is "empty". $\endgroup$ Jun 10, 2018 at 20:22

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