Research output: Contribution to Journal/Magazine › Journal article › peer-review
Research output: Contribution to Journal/Magazine › Journal article › peer-review
}
TY - JOUR
T1 - Direct numerical simulation of a non-premixed impinging jet flame
AU - Jiang, Xi
AU - Zhao, Hua
AU - Luo, Kai H.
PY - 2007/8
Y1 - 2007/8
N2 - A non-premixed impinging jet flame at a Reynolds number 2000 and a nozzle-to-plate distance of two jet diameters was investigated using direct numerical simulation (DNS). Fully three-dimensional simulations were performed employing high-order numerical methods and high-fidelity boundary conditions to solve governing equations for variable-density flow and finite-rate Arrhenius chemistry. Both the instantaneous and time-averaged flow and heat transfer characteristics of the impinging flame were examined. Detailed analysis of the near-wall layer was conducted. Because of the relaminarization effect of the wall, the wall boundary layer of the impinging jet is very thin, that is, in the regime of viscous sublayer It was found that the law-of-the-wall relations for nonisothermal flows in the literature need to be revisited. A reduced wall distance incorporating the fluid dynamic viscosity was proposed to be used in the law-of-the-wall relations for nonisothermal flows, which showed improved prediction over the law of the wall with the reduced wall distance defined in terms of fluid kinematic viscosity in the literature. Effects of external perturbation on the dynamic behavior of the impinging flame were found to insignificant.
AB - A non-premixed impinging jet flame at a Reynolds number 2000 and a nozzle-to-plate distance of two jet diameters was investigated using direct numerical simulation (DNS). Fully three-dimensional simulations were performed employing high-order numerical methods and high-fidelity boundary conditions to solve governing equations for variable-density flow and finite-rate Arrhenius chemistry. Both the instantaneous and time-averaged flow and heat transfer characteristics of the impinging flame were examined. Detailed analysis of the near-wall layer was conducted. Because of the relaminarization effect of the wall, the wall boundary layer of the impinging jet is very thin, that is, in the regime of viscous sublayer It was found that the law-of-the-wall relations for nonisothermal flows in the literature need to be revisited. A reduced wall distance incorporating the fluid dynamic viscosity was proposed to be used in the law-of-the-wall relations for nonisothermal flows, which showed improved prediction over the law of the wall with the reduced wall distance defined in terms of fluid kinematic viscosity in the literature. Effects of external perturbation on the dynamic behavior of the impinging flame were found to insignificant.
KW - direct numerical simulation
KW - heat transfer
KW - impinging flame
KW - law-of-the-wall
KW - viscous sublayer
KW - wall
KW - HEAT-TRANSFER CHARACTERISTICS
KW - TURBULENT CHANNEL FLOW
KW - WALL INTERACTION
KW - BOUNDARY-CONDITIONS
KW - COMBUSTION
KW - DYNAMICS
KW - SCHEMES
KW - SURFACE
KW - FLUXES
U2 - 10.1115/1.2737480
DO - 10.1115/1.2737480
M3 - Journal article
VL - 129
SP - 951
EP - 957
JO - Journal of Heat Transfer
JF - Journal of Heat Transfer
SN - 0022-1481
IS - 8
ER -