Discussion Forum

Dear all,

I would like to ask you for help in modeling surface corona discharge. In more detail, I need to examine the acoustic emission from this type of discharges, created due to ionic wind between the electrodes. Therefore, I don’t need to model the entire physics of the discharge. I use the common approach of modeling it in COMSOL, namely, create the study, using electrostatics + transport of diluted species module to calculate volume charge and CFD module to calculate the air flow.

If I add the AC voltage to the DC one (electric potential at emitter is written, as V0+2e3sin(2pifreq1t) , V0 = 10 kV), I change the distribution of space charge and strength of electric field, that in turn influences the airflow. The oscillations of the airflow create the perturbations of pressure and, consequently, acoustic emission. I am satisfied with results from electrostatic study and turbulent flow since they look reasonable and I compared them with couple of papers, (for example https://doi.org/10.1016/j.jclepro.2018.06.250), using different geometry. Unfortunately, I don’t clearly understand how to include acoustics to my study. Electrostatics and turbulent flow are calculated as Time dependent studies. I would like to implement the flow behavior (velocity field, time dependent) that is a result of turbulent flow study into acoustics and derive acoustic waves propagation. I try to use linearized navier-stokes transient interface, and include the volume force from turbulence as the domain source. The results look strange: I can’t examine them, unfortunately. The problem might be, that navier-stokes acoustic interface expects the background flow to be stationary that is not my case. I would appreciate any advice and help on how to study acoustics in this case.