MATHEMATICAL MODELING OF A SUPERSONIC TWIN JET INTERACTION WITH AN OBSTACLE

The paper presents the results of the mathematical modeling of a supersonic twin jet interaction with an obstacle for the Mach number of 4.5 specified at the nozzle exit. Mathematical formulation of the problem includes a system of Favre-averaged Navier-Stokes equations and SST turbulence model for a viscous compressible ideal gas. The calculations are carried out using the free software OpenFOAM Extended with the Godunov method employed. The effect of the distance between nozzles on the shock-wave structure of the gas flow and on the force action of the plumes on the obstacle is studied. The distance between the nozzles varied in the range of 0.1−4. It is found that with an increase in the distance from 0.1 to 0.5, the flow structure is significantly rearranged, and two pressure maxima arise, which increase in comparison to the distance of 0.2. A decrease in pressure on the obstacle is observed at the distance over 1.0. For a distance of 4, two pressure maxima occur on the axis of each jet, while the force action of each jet is half as high as the resultant jet force action for a distance of 0.1. The transition from a stationary regime to a self-oscillating one is observed when the distance exceeds the value of 1.5.