  We examine the changes in kinetic energy dissipation of a turbulent channel
flow caused by a spanwise magnetic field. The numerical study is based on our
simulation data from [Krasnov, Zikanov, Schumacher, Boeck, Phys. Fluids 20,
095105 (2008)] obtained by direct and large eddy simulations. We find that the
Joule dissipation can exceed the viscous dissipation in the weakly dissipative
bulk region, but remains comparatively small in the turbulence-generating
near-wall region.
