Simulation of viscous gas flow through tapered conic nozzles
The unsteady viscous gas compressible flow through the tapered nozzle is calculated. The calculations are performed in an axisymmetric formulation. The computational process was parallelized using MPI technology. Data was received using «Uran» supercomputer of IMM UB RAS. For accurate integration of Navier-Stokes equations with adequate reproduction of physical effects high-order approximation WENO scheme was used for calculation spatial derivative and second-order TVD Runge-Kutta scheme was used for time integration. The nozzle taper angle was a variable parameter. Fields of instantaneous and average velocity were analyzed. It is shown, that the taper angle increasing cause the flow rate decreasing. In a nozzle with a large tapering angle, the flow is noticeably accelerated, while the border regions occupy a much smaller space being displaced by the flow core. In a cylindrical nozzle with a zero taper angle nonzero kinetic energy is distributed over the entire length of the nozzle. In a nozzle with a taper angle of 1.5 degrees the kinetic energy of turbulence has only rare bursts, remaining close to zero in almost the entire region. The nozzle flow rate decreases when taper angle increasing. There is no direct relationship between the drop in flow and the decrease in the critical section area.