Interaction of opposed underexpanded jets from micronozzles

This paper presents the results of parametric studies of the interaction features of supersonic under-expanded argon jets, flowing from coaxial opposite micro-nozzles. A mathematical model of viscous compressible gas based on the classical Navier-Stokes equations supplemented by the equations of state of a perfect gas was used for numerical modelling of the gas dynamics of supersonic jets. The problem was solved in a two-dimensional axisymmetric formulation within the framework of the hypothesis of symmetric flow interaction. The problem was solved by the control volume method The Godunov method was used to discretize the convective terms, and linear interpolation of the values on the edges of the control cells was used to discretize the dissipative terms. Time integration was performed by the third-order Runge-Kutta method. Parametric analysis was aimed at evaluating the influence of the nozzle spacing on the size of the jet interaction region, as well as the density level in this zone. The obtained distributions of the main gasdynamic quantities allowed us to describe the flow structure and estimate the shape and size of local flow zones, as well as the density level in the contact region of two supersonic microjets. Analysis showed that a denser zone can be obtained by bringing the nozzles closer together, but in this case its longitudinal size decreases, which should be taken into account when planning experimental studies.