Ionizing Air (Electro Aerodynamics)

[Nukedropout]

How fast does an air molecules velocity through an electrostatic field have to be to induce ionization? Stated simply, how much friction is needed to cause ionization. Is it possible to factor in velocity, temperature(at room temperature), and strength of the static field, using a math equation to figure out how fast air's speed must be to ionize?

Is it possible to cause ionization of air and induce acceleration? Is that what air ionizers (electric air filters) do?

<----- video on particles accelerating across a electrically charged surface. Very interesting...

 

[Drakkith]

It is actually the electric potential that ionizes the air molecules and accelerates them. IE you apply a high enough voltage and you rip the electrons off of the air molecules and accelerate them one way and the now ionized air molecules the other way.

 

[ZapperZ]

How fast does an air molecules velocity through an electrostatic field have to be to induce ionization? Stated simply, how much friction is needed to cause ionization. Is it possible to factor in velocity, temperature(at room temperature), and strength of the static field, using a math equation to figure out how fast air's speed must be to ionize?

Is it possible to cause ionization of air and induce acceleration? Is that what air ionizers (electric air filters) do?

<----- video on particles accelerating across a electrically charged surface. Very interesting...

There are several different things being mixed here.

If you want to know how the sparks or air breakdown is created, I've already summarized briefly how that occurs:

https://www.physicsforums.com/showthread.php?t=651310

Note that ionization can be induced in many different ways. The ionization in your fluorescent light tubes is due to bombardment of the gas molecules with electrons. Alternatively, one can certainly achieve that we a high-enough external electric field.

Zz.

 

[boneh3ad]

How fast does an air molecules velocity through an electrostatic field have to be to induce ionization? Stated simply, how much friction is needed to cause ionization. Is it possible to factor in velocity, temperature(at room temperature), and strength of the static field, using a math equation to figure out how fast air's speed must be to ionize?

If by this you are referring to the ionization of air in front of a re-entry vehicle entering the atmosphere, then it isn't friction that causes this, it is the temperatures associated with compression across the shock wave. In those cases, the temperatures can be similar to the surface of the sun, so naturally air will ionize and become a plasma at that temperature.

If instead you were talking about the kind of stuff shown in the video, that has nothing to do with speed. That was, as someone mentioned earlier, from subjecting the air to a strong electric field to ionize and accelerate the air molecules.

Is it possible to cause ionization of air and induce acceleration? Is that what air ionizers (electric air filters) do?

You absolutely can, and there is a pretty large body of work doing exactly this. In fact, in the video you posted, there were a couple shots of the separated flow over an airfoil being reattached. Those make use of this principle by injecting momentum into the boundary layer just before it separates to help keep it attached. They have also looked into similar idea for creating plasma-based flaps and slats for wings and rudders for the vertical stabilizer on a plane, though these kinds of technologies are nowhere near ready to be fielded.

 

[sardar]

I can provide some information on ionizing air and the factors that can induce it. Ionization is the process of removing electrons from atoms or molecules, resulting in the formation of ions. In the case of air, this means that some of the air molecules become positively or negatively charged.

The velocity of air molecules through an electrostatic field does not necessarily determine the level of ionization. Instead, it is the strength of the electric field that plays a crucial role. The higher the electric field strength, the greater the likelihood of ionization occurring. However, the velocity of air molecules can affect the rate of ionization, as faster-moving molecules will have more collisions with the charged particles in the field.

There is no specific equation that can determine the exact velocity of air molecules needed for ionization to occur. This is because it depends on various factors such as the strength of the electric field, the temperature of the air, and the composition of the air. However, researchers have developed models that take into account these factors to estimate the velocity needed for ionization to occur.

As for inducing acceleration, it is possible to use electric fields to accelerate charged particles. This is the principle behind air ionizers or electric air filters, where an electric field is used to remove particles from the air and collect them on oppositely charged plates. However, it is important to note that this is not the same as ionizing the air itself, as the particles are already ionized before being accelerated.

In summary, the velocity of air molecules through an electrostatic field can affect the rate of ionization, but the strength of the electric field is the main factor. It is possible to estimate the velocity needed for ionization to occur using mathematical models, and electric fields can be used to accelerate charged particles, but this is not the same as ionizing the air.