cuHARM
cuHARM
cuHARM is a graphics processing unit (GPU) accelerated code designed to solve the 3D general relativistic radiation magneto-hydrodynamic (GR-MHD) equations in the context of accretion disk/jet systems. It is written in CUDA-C with additional parallelism levels provided by nested use of openMP (multiple GPUs on 1 node) and MPI (multi-node with multiple GPUs).
A radiation module was recently added to cuHARM. It directly solves for the radiative transfer equation to calculate the radiation 4-force. This method is different from the usual approach in which the moment formalism is applied.
More details soon.
Black hole spin: -0.94
Resolution: 256x128x128
Magnetic field: single poloidal loop with beta_0 = 100
Initial disk: Fishbone and Moncrief (1976) with rin = 20 and rmax = 41
Credit: G.Q. Zhang, D. Bégué et al. (2024)
Publications with cuHARM:
Wallace, Bégué, and Pe’er, Direct Solution of the Time-Dependent Covariant Radiative Transfer Equation and its Coupling to General Relativistic Magnetohydrodynamics with cuHARM, submitted for publication to ApJ.
Singh, Bégué, and Pe’er, Radiative cooling changes the dynamics of magnetically arrested disks. Analytics, 2025, ApJL 981 L11.
Zhang, Bégué, Pe’er and Zhang, A study of the MAD accretion state across black hole spins for radiatively inefficient accretion flows, 2024, ApJ 962 2 135 [Journal] [Arxiv]
Bégué, Pe'er et al, cuHARM: a new GPU accelerated GR-MHD code and its application to ADAF disks, 2023, ApJS 264 32 [Journal] [Arxiv]