Numerical simulation of laminar circular and noncircular jets in cross-flow
Direct numerical simulations have been performed to investigate the complex process of three-dimensional ow interactions around square, round and elliptic jets injected normally into the cross- ow mainstream. The velocity ratio of the jet to that of the cross- ow is 2.5 and the Reynolds number based on the free stream quantities and the jet exit diameter is 225. The main objective of this study is to assess the effect of the hole exit geometry on the dynamics of large-scale structures in jets cross- ow interactions. The computer code uses a finite-difference methodology, which solves the compressible three-dimensional unsteady Navier–Stokes and total energy equations in the Cartesian coordinate system. The obtained results reveal that, for all cases of hole geometry, the near field of the jet is dominated by the large-scale dynamic structures of complex ow nature. These ow structures undergo several interaction mechanisms and processes including reconnecting and pairing phenomena. The identified structures include the counter rotating vortex pair (CRVP), the Kelvin-Helmholtz roll- up of the jet shear layer vortices and the horseshoe vortex system. Our results also show that the jet lift-off as well as the cross- ow entrainment into the near wall regions mechanisms depend on the hole geometry. The maximum jet lift-off is found in the elliptic hole geometry case. These findings are in good agreement with existing experimental observations qualitatively.
DNS jet in cross ow jet hole geometry large scale vortex structures dynamics
M.Maidi Y.Yao J.Yao
Faculty of Engineering, Kingston University, London SW15 3DW, United Kingdom
国际会议
The Fifth International Conference on Fluid Mechanics(第五届国际流体力学会议)
上海
英文
2007-08-15（万方平台首次上网日期，不代表论文的发表时间）