Air-oil heat exchanger

An air/oil heat exchanger, comprising:

• a radially internal wall,
• a radially external wall, and
• a plurality of partitions, some of the partitions are hollow and through which oil passes, the partitions, and the radially internal wall, and the radially external wall are delimiting corridors among which parietal corridors delimited by the radially internal wall and the radially external wall and the adjoining partitions, and central corridors at a distance from the radially internal wall and the radially external wall and delimited only by the partitions, the corridors allowing air flow to pass through the air/oil heat exchanger, wherein at an inlet of the air/oil heat exchanger, the internal parietal corridors and/or the external parietal corridors each define a radial height that is less than a radial height of the central corridors, and a height of the internal and/or external parietal corridors is half that of a height of the central corridors.