DIRECT SIMULATION MONTE-CARLO SIMULATION OF THE INTERACTION BETWEEN RAREFIED FREE JETS

This paper presents a direct simulation Monte Carlo (DSMC) calculation of two interacting free jets exhausting into vacuum. The computed flow field is compared against available experimental data and shows excellent agreement everywhere except in the very near field (less than one orifice diameter downstream of the jet exhaust plane). The lack of agreement in this region is attributed to having assumed an inviscid boundary condition for the orifice lip. The results serve both to validate the DSMC code for a very complex, three-dimensional, nonequilibrium flowfield, and to provide some insight into the complicated nature of this flow.