PREDICTIONS OF A TURBULENT REACTING JET IN A CROSS-FLOW

The article presents an application of a finite-difference scheme for solving the fluid dynamic equations of three-dimensional elliptic flow to the problem of a turbulent reacting jet discharging perpendicularly into an unconfined cross-flow. The mathematical model employs a standard two-equation, k-epsilon model to calculate the distribution of Reynolds stresses, with the turbulent nonpremixed combustion process being modeled via the conserved scalar/prescribed probability density function approach. The laminar flamelet concept is used to specify the instaneous thermochemical state of the combusting mixture. In In order to assess the ultimate usefulness of the model for predicting the consequences associated with atmospheric venting and flaring of flammable gases, solutions of the model are compared with experimental data for natural gas flames obtained from wind tunnel studies by Birch et al. Over a range of ratios of cross-flow to jet velocity, predictions of flame trajectory and length are in reasonable qualitative agreement with experimental data. At one particular velocity ratio, for which detailed measurements of the mean temperature field of the flame are available, close agreement between theory and experiment is obtained provided the effects of flame liftoff and radiative heat loss are incorporated into the turbulent flow calculation.