MEAN FLOW AND TURBULENCE MEASUREMENTS IN A TRIANGULAR TURBULENT FREE JET

Detailed mean flow and turbulence measurements were made, using hot-wire anemometry, in the near flow field of a turbulent, incompressible air jet issuing from a sharp-edged equilateral triangular slot into stagnant air surroundings. The measured quantities included the three components of the mean velocity vector, the three turbulence intensities, and two of the Reynolds shear stresses. The results indicate that the jet spreads faster on its base side than at its apex. This difference in spreading leads to an inversion of the jet shape at about five equivalent slot diameters downstream from the slot exit plane. The Reynolds shear stress levels, compared to those found in round turbulent free jets at the same downstream locations, are higher in the triangular jet, implying improved mixing. © 1990.