A numerical and experimental study of the time-evolution of a low Mach number jet

We present a comparison between a plasma-generated 'starting jet' experimen t and an axisymmetric numerical simulation of the flow. The experimental fl ow and the numerical simulation give results that agree both qualitatively and quantitatively, showing that the complex vortical structures arising in the flow are surprisingly well reproduced by the numerical model. This res ult inspires confidence in the accuracy of astrophysical jet numerical simu lations. Also, even though the Mach number of our laboratory jet is somewha t low (M similar to 0.5), the dimensionless parameters of this jet are not very far from those expected for Faranoff-Riley class I radio jets.