A new two phase separator for use in space applications has been invented. It is a vortex separator designed to accommodate gas driven two phase flows of gas and liquid. The work presented here is a first of a kind study of this newly invented separator and is meant to determine the minimum inlet gas flow rate necessary for a stable vortex inside the separator for different separator geometries. A dimensional scaling analysis was done to predict this minimum inlet gas flow rate. Experiments were performed on the ground and in conjunction with NASA using their microgravity simulating plane to determine this minimum inlet gas flow rate. The results of the experiments and scaling analysis are compared.
The new design consists of two chambers, a vortex generator and a separation chamber, meant to divide the functions of vortex creation and phase separation. The two phase flow is injected tangentially into the vortex generator causing the inlet linear momentum to be transformed into azimuthal momentum. The two phase mixture in the vortex generator then moves into the separation chamber where the two phases separate due to the density difference between the phases.
The dimensional scaling analysis used the Weber number to predict the minimum rotational velocity of the spinning flow in the separation chamber during a stable vortex. This rotational velocity was related to the inlet gas flow rate by the inlet momentum rate. The scaling used the dimensions of each separator tested to predict the minimum inlet gas flow rate needed for a stable vortex.
In all, twelve separators were tested, eleven on the ground and one on the plane. The ground testing was a parametric study varying the sizing of the separator components. The flight experiments kept the separator geometry constant and varied the gravitational field in which the separator operated. In general, the minimum inlet gas flow rate increased with the ratio of separation chamber diameter to vortex generator diameter. This same trend was consistent with the dimensional scaling analysis. Also, the inlet flow rate increases with gravitational acceleration.