NUMERICAL STUDY OF A HEATED PULSED AXISYMMETRIC JET IN LAMINAR MODE

In this work, we have studied numerically the influence of a pulsation on the flow generated by an axisymmetric immerged jet in a laminar mode. A finite-difference method is used to solve the dimensionless equations governing the flow. The simulation enabled us to determine the space-time evolution of the flow variables, such as the velocity components, temperatures, length of the potential core, and both the dynamic and thermal half-thicknesses. The results obtained are the outcome of various factors such as the pulsation amplitude, the frequency which affects the Strouhal number value, and the Reynolds and the Grashof numbers. All of them show that a pulsed jet reaches an asymptotic mode identical to that of the steady one. On the other hand, the pulsation considerably accelerates the expansion of the jet and clearly improves the entrainment at the nozzle exit for distances of some diameters. The results reached in this work are validated with those obtained for a steady jet in its various aspects.