Effects of internal pressure and inlet velocity disturbances of air and fuel droplets on spray combustion field are investigated by means of two-dimensional direct numerical simulation (DNS). n-decane (C10H22) is used as liquid spray fuel, and the evaporating droplets' motions are tracked by a Lagrangian manner. The pressure perturbation is captured by employing a pressure-based semi-implicit algorithm for compressible flows. The frequency and magnitude of the inlet velocity disturbances are set at 800 Hz and up to 50 %, respectively, and the internal pressure is set at 0.1 or 0.5 MPa. The results show that the pressure perturbation in the spray combustion field is enhanced by combustion reaction and increase in internal pressure. In addition, the inlet velocity disturbances do not change the frequency indicating the peak of power spectra of pressure perturbation, but decrease the intensity of pressure perturbation for the cases of 0.5 MPa.
2013 by The Japan Society of Mechanical Engineers and The Heat Transfer Society of Japan