Abstract

OLENTINO MASGO, San Luis B.; NAKKA, Richard; CARABALLO, Simón  and  MIREZ, Jorge. Numerical simulation of the under-expanded flow in the experimental conical nozzle helios-x. Ingenius [online]. 2021, n.25, pp.81-93. ISSN 1390-860X.  https://doi.org/10.17163/ings.n25.2021.08.

Numerical studies of the flow field for convergentdivergent nozzles with throat length, have reported fluctuations of the flow with oblique shock waves in the throat section, for the overexpanded flow condition. However, for other flow conditions, for the same type of nozzle, knowledge is limited. In the present work, the objective is to determine the behavior of the flow in the throat length and in the divergent, for an experimental conical nozzle classified as Helios-X, for the underexpanded flow condition. 2D numerical simulations of the flow field were performed with the ANSYS-Fluent version 12.1 code, applying the RANS model. The governing equations for compressible flow, conservation of mass, momentum, energy, and state were used; as well as, for turbulence, the Menter SSTk − ω model and for the viscosity as a function of temperature the Sutherland equation. In the section of the throat adjacent to the wall the flow exhibited fluctuations; in the axial symmetry the flow showed a stepped acceleration; in the divergent section the flow slowed in a certain region; however, the flow exited the nozzle at a supersonic speed slightly greater than Mach 3. It is concluded that in the throat length section there is a flow pattern, as well as in the divergent section.

Keywords : Throat; Fluctuation; Under-expanded; Simulation; Nozzle.

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