udf for ehd

suribabu

I written udf for transport equation for solving charge density. in my udf

1 i solved for voltage using uds0 2 using above uds i solved for electric field define_adjust(domain,t) 3)using 2 I solved transport equation for charge density by using macro define_uds_flux(name,f,t,i)

IF u see this paper they described problem.u can see domain. ***for boundary conditions------------------- AT wire voltage =25kv at collector plate voltage = 0 remaining is symmetry BUT charge density on the wire is not constant. THIS will varry based on electric field. THIS is solved by iteratively . for this i written udf using define_profile() i supplied this profile to on the wire. but i did not got the results. PROFILE IS charge density on wire_new =old_charge+q*(1-alph) alpha is under relaxation q*=Ewire/Eonset Can any body give any advice on this .