Flashing flow in the rotating curved channels with variable cross-section of a two-phase flow turbine

摘要

The rotating flash flow has rarely been studied, although its characteristics affect significantly the performance of the two-phase flow turbine. In this paper, through analyzing the flashing flow obtained by CFD methods, which is validated with the experimental data, the relationships of average flow parameters under various rotational speeds were studied theoretically and numerically using the flow equations established on the Frenet coordinate system. The ratio of the mass flow rate under various rotational speeds was formalized and found to be dependent on the rotational speed and thermophysical properties. The generation and development of vapour were revealed and correlated to the geometry of the channel. The secondary flow in the flashing rotating channel was discussed and found to rotate in opposite directions upstream/downstream of the throat. The flashing induced near the throat had the effect on flow homogenizing in the normal direction of the cross-section. The analysis could be further applied to the analogy of the secondary flow between the rotating single-phase flow and the rotating flashing flow.