The behaviour of platelet flows in plasma and the change of the platelet surfaces is studied by numerical simulations. In particular, the influence of the 2D platelets surface roughness and Reynolds number on the rotation of platelets is considered. Reynolds numbers $Re$ vary from 0.4 to 50 and it is noted that if $Re = 50,$ the 2D platelets stop rotating after 90$^{\circ}$ turn. If $0.4 ≤ Re ≤ 20,$ the rotation period increases along with the increase of Reynolds number. The maximum angular velocity, the minimum angular velocity and the rotation period of platelets depends on their roughness. However, these characteristics are little affected by the roughness if the Reynolds number is close to 1. It is also worth noting that the torque of 3D platelets is greater than the torque of 2D platelets.