We explore the effect of the magnetic Prandtl number Pm on energy and dissipation in fully-resolved direct numerical simulations of steady-state , mechanically-forced homogeneous magnetohydrodynamic turbulence in the range 1 / 32 < Pm < 32 .
We compare the spectra and show that if the simulations are not fully resolved , the steepness of the scaling of the kinetic-to-magnetic dissipation ratio with Pm is overestimated .
We also present results of decaying turbulence with helical and nonhelical magnetic fields , where we find nonhelical reverse spectral transfer for Pm < 1 for the first time .
The results of this systematic analysis have applications ranging from stars , planetary dynamos , and accretion disks .