Mean flow and turbulence measurements of the impingement wall jet on a semi-circular convex surface

Abstract.

The detailed mean flow and turbulence measurements of a turbulent air slot jet impinging on two different semi-circular convex surfaces were investigated in both free jet and impingement wall jet regions at a jet Reynolds number Re _w=12,000, using a hot-wire X-probe anemometer. The parametric effects of dimensionless circumferential distance, S/W=2.79–7.74, slot jet-to-impingement surface distance Y/W=1–13, and surface curvature D/W=10.7 and 16 on the impingement wall jet flow development along a semi-circular convex surface were examined. The results show that the effect of surface curvature D/W increases with increasing S/W. Compared with transverse Reynolds normal stress, $\overline {v^2 } /U_{\rm m}^2$ , the streamwise Reynolds normal stress, $\overline {u^2 } /U_{\rm m}^2$ , is strongly affected by the examined dimensionless parameters of D/W, Y/W and S/W in the near-wall region. It is also evidenced that the Reynolds shear stress, $- \overline {uv} /U_{\rm m}^2$ is much more sensitive to surface curvature, D/W.