Spontaneous condensation of nitrogen in a flat nozzle in a cryogenic wind tunnel

This paper examines a two-dimensional flow of a spontaneous condensing gas. The results of calculation of nitrogen flows in a flat model nozzle are presented and compared with the calculation of steady flow in one- and two-dimensional formulations with different numbers of cells over the coordinate. Calculations performed in a unidimensional formulation show the successive realization of three types of oscillatory flow states with a decrease in the stagnation temperature. The frequency characteristics obtained in the two-dimensional formulation agree well with those given by the unidimensional formulation.