The present study reports on experimental information regarding the turbulent free convection flow and thermal field structure, along an isothermally heated vertical flat plate with ribs. The hight to distance ratio of the ribs was equal to 0.1.

The obtained experimental data consist of visualization of the flow, as well as detailed mean temperature and turbulent intensity distribution measurements covering the ribbed part of the heated plate. Heat transfer rates and their enhancement, due to the presence of the ribs, have been estimated from the obtained temperature profiles and by using Newton’s cooling law. Comparisons with corresponding measurements in forced convection reported in the literature, are also made.

The described experiments constitute a first approach towards a more detailed investigation regarding the significant free convection currents existing under certain conditions in cooled channels. However, they also reveal some physical aspects of the heat transfer enhancement processes in ribbed surfaces which are believed to be applicable in more general situations and could lead to establishing some design criteria for ribbed surfaces.

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