Resumen

TOLENTINO, San Luís  y  CARABALLO. Numerical  simulation of the air flow with shock wave in a transonic diffuser. uct [online]. 2017, vol.21, n.82, pp.4-15. ISSN 1316-4821.

In the present paper, two 2D simulations of the air flow are made in a transonic diffuser: the first with pressure ratio P _sal /P _ent =0.82 for a weak shock wave, and the second with pressure ratio P _sal ⁄P _ent =0.72 for a strong shock wave. The domain of the transonic diffuser was considered with adiabatic walls, meshed with 17900 quadrilateral cells, and simulated with the ANSYS-Fluent code that applies the finite volume method. The fundamental equations applied in the code are: the equation of conservation of mass, amount of movement, energy, and the equation of state. The density-based analysis for a compressible fluid was considered. The Menter turbulence model was used, and for the viscosity the Sutherland equation. From the results obtained, for the first case: most of the trajectories of the pressure and velocity numerical curves are superimposed with the experimental pressure and velocity data of the Bogar and Salmon works, except certain short sections of the numerical curves are separated from the experimental data. For the second case, the trajectories of the numerical curves of velocity, Mach number, pressure, temperature and density, along the diffuser on the x-axis direction, show their maximum and minimum values; and it is observed in the temperature profile how the fluid temperature drops to a minimum value, and how it increases during the shock wave. It is concluded that the Menter turbulence model presents satisfactory results. Where the weak shock wave and strong shock occur, there are some reference points where the maximum velocity of the flow is supersonic. For a region of the fluid that is slightly away from the diffuser wall, its static temperature during the weak shock wave and strong shock is less than 273.15 K (0.0 ° C).

Palabras clave : Transonic diffuser; Turbulence model; Shock wave; Static temperature.

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