Mass loss of the cloud versus time for the blob test simulations. Particles are defined as a cloud member if their temperatures and densities fulfill the conditions T_i < 0.9T_ext and ρ_i > 0.64ρ_cl. Left panel: simulations have been performed incorporating the AC term into the SPH equations and using the kernels CS, CRT, and M₅. For the CS kernel, a simulation is also shown as reference without AC (NOAC, solid black line). Right panel: for the CS kernel, simulations with additional constraints on the particle AC parameters  have been performed using N = 10⁶ (N6) and N = 10⁵ (N5) particles, see text for more details. Black squares have been extracted from Fig. 10 of Springel (2011) and indicate the behavior of the cloud mass versus time in a similar test performed using the moving-mesh code AREPO and with (64 × 64 × 128) resolution elements.