Effect of injector variation on the bidirectional vortex

The primary goal of this work is to assess the sensitivity of the bidirectional vortex to changes in injection conditions. To achieve this goal, a parametric model is developed to capture the effect of variations in number of injectors, injector size, injection velocity, and injection location. The resulting cold-flow model is simulated using OpenFOAM, an open source platform for the solution of fluid dynamics problems. The accuracy of the solver is validated through comparisons to existing analytical models. After the validation is complete, simulations are run to examine the response of the vortex to changes in the injector design. The resulting axial and velocity profiles are be compared to evaluate the sensitivity of the vortex structure to the injection conditions. It is found that increasing mass flow rate by way of injector number, injector size, and injection velocity all have an amplifying effect on the peak velocities in all directions. Changes in the injection height have a nominal effect on the swirl and radial velocities, but a more significant impact on the axial velocity.