Experimental verification of the optical similarity of jets of a heated molecular gas

Agreement i s obtained between measurements of the gasdynamic and optical characteristics of submerged subsonic turbulent jets heated to $850$ K. It is established that a universal function describes the field of spectral distribution of brightness energy and radiation intensity at frequencies where the radiation is of a spatial nature. The scale of the function is a combination of the initial parameters of the flow, while its argument consists of dimensionless variables in which flow is self-similar.