Hello,
I am working on a design of an injection nozzle, where an ohmic heating is implemented in the nozzle to heat up our product passing through it. it is a rectangular nozzle, where there are two parallel stainless steel electrodes in one direction and two polycarbonate wall in the other direction . by simulation we obtain a parabolic temperature profile, in the electrodes direction, where it is higher on the wall (electrodes) than the one at the center. but by experiments, this parabolic we obtain a profile which is reduced to almost obtain a flat profile and the difference is almost negligible. if I want to compare simu and experimental results, at the center i have almost the same temperature at the center output, but in the direction of electrodes the wall temperatures are far higher with simulation, i need to know if there are any ideas about this ?
one another problem, in reality we dont reach steady state because of the inverse convection diffusion in the nozzle, the inlet temperature is affected and increases little bit with time. ! how can i model this with comsol ?
NB: for electrodes, i use the caracteristics of the experimental materials. and i consider a natural convection conditions.