[m.r.soufivand]

In plasma actuators simulation, voltage discharge is added to the momentum equation usually in the form of a source term. What is the solution if we want to simulate hypersonic flow (such as the re-entry of a shuttle into the atmosphere) that the fluid is ionized by the flow regime or special flowfield which air is ionized by temperature?

[LuckyTran]

In plasma actuators and such there is an external source, the actuator!

For hypersonic flows, you don't need anything special. You just need the right equation of state for internal energy / enthalpy (aka give the right specific heat table).

[m.r.soufivand]

thanks for your answer. can you give me more information? if you discharge of voltage in air or rise its temperature up, how could you find out how much of particles of the air is ionized?

[m.r.soufivand]

Originally Posted by LuckyTran

In plasma actuators and such there is an external source, the actuator!

For hypersonic flows, you don't need anything special. You just need the right equation of state for internal energy / enthalpy (aka give the right specific heat table).

I guess its need to Navier-Stokes in the multitemperature approximation.

[LuckyTran]

If you discharge a voltage in air, you provide and convert electrical energy to internal energy.

In high speed flows, the gas heats up due to adiabatic compression. The temperature rises due to conversion of mechanical energy of the flow into internal energy. However, this energy is already accounted for in the total energy equation.

If you care about the detailed chemical reactions that occur, then you need to add addition species transport equations for the relevant chemical compounds and then provide reaction rate equations. However, as far as the Navier-Stokes and Energy equation are concerned, you do nothing. Well technically you do modify the enthalpy to also be a function of each of the species mass fractions, but that is again just having the right enthalpy.

[m.r.soufivand]

Originally Posted by LuckyTran

If you discharge a voltage in air, you provide and convert electrical energy to internal energy.

In high speed flows, the gas heats up due to adiabatic compression. The temperature rises due to conversion of mechanical energy of the flow into internal energy. However, this energy is already accounted for in the total energy equation.

If you care about the detailed chemical reactions that occur, then you need to add addition species transport equations for the relevant chemical compounds and then provide reaction rate equations. However, as far as the Navier-Stokes and Energy equation are concerned, you do nothing. Well technically you do modify the enthalpy to also be a function of each of the species mass fractions, but that is again just having the right enthalpy.

Thank you so much, It was so helpful.
Best regards