Electrical device having heat generating components with improved heat removal using turbulent flow

An electric device comprising a portion generating heat and at least one heat dissipating portion for dissipating said generated heat by heat exchange with a fluid, wherein said at least one heat dissipating portion comprises means for generating a turbulent flow in the fluid,

• wherein the means for generating the turbulent flow comprises ribs positioned so to be in contact with the fluid where a plurality of the ribs are oriented parallel one to each other, wherein each of the ribs is a solid elongated body that develops longitudinally on a single surface side of the at least one heat dissipating portion and is orientated in a longitudinal direction that is transversal to the main flow direction of the fluid,
• wherein the ribs of said plurality of ribs are grouped in a plurality of groups, wherein each group comprises a plurality of parallel ribs, the ribs in each group being dimensioned such that their ends across the group define two opposite sinusoidal waves, wherein a first group having two opposite first sinusoidal waves is in a first row and a second group in a second row directly above or directly below the first row has two opposite second sinusoidal waves offset from and parallel to the two opposite first sinusoidal waves.