Influence of the blowing through a porous flat plate and a circular cylinder has been studied. Experimental and numerical results agree and show a thickening of the boundary layers, both dynamic and thermal. The thermal protection effectiveness has been quantified for the two geometries, and comparisons between discrete injection and blowing, in the case of the flat plate, were carried out, showing a stronger impact of the latter. Finally, the blowing influence on the primary instability properties results in a decrease of the vortex shedding frequency and a modification of the shear layer.  Influence of the blowing through a porous flat plate and a circular cylinder has been studied. Experimental and numerical results agree and show a thickening of the boundary layers, both dynamic and thermal. The thermal protection effectiveness has been quantified for the two geometries, and comparisons between discrete injection and blowing, in the case of the flat plate, were carried out, showing a stronger impact of the latter. Finally, the blowing influence on the primary instability properties results in a decrease of the vortex shedding frequency and a modification of the shear layer. 