  We perform magnetohydrodynamic simulations in full general relativity of disk
accretion onto nonspinning black hole binaries with mass ratio 36:29. We survey
different disk models which differ in their scale height, total size and
magnetic field to quantify the robustness of previous simulations on the
initial disk model. Scaling our simulations to LIGO GW150914 we find that such
systems could explain possible gravitational wave and electromagnetic
counterparts such as the Fermi GBM hard X-ray signal reported 0.4s after
GW150915 ended. Scaling our simulations to supermassive binary black holes, we
find that observable flow properties such as accretion rate periodicities, the
emergence of jets throughout inspiral, merger and post-merger, disk
temperatures, thermal frequencies, and the time-delay between merger and the
boost in jet outflows that we reported in earlier studies display only modest
dependence on the initial disk model we consider here.
