EFFECTS OF PERIOD OF THE INLET FLUCTUATING VELOCITY DATA ON THE DIRECT NUMERICAL SIMULATION OF TURBULENT PREMIXED JET FLAME

A direct numerical simulation of turbulent premixed planar jet flame is conducted. The fluctuating velocity field at the jet inflow boundary is generated based on the energy spectrum of isotropic decaying turbulence. The effects of the period of the fluctuating velocity data on the simulation results are investigated. When the period is larger than the total time for simulation, the computational instantaneous results at different times exhibit obvious differences. The time-averaged gas temperature, velocity, and species concentrations are obtained and they are in a steady state. While the period is less than the total time for simulation, the computational results are affected by the cyclic utilization of the inlet fluctuating velocity data. The periodicity appears in the instantaneous results.