The ornamental design for a vortexwaterflowaccelerator, as shown and described.
FIG. 1 is a perspective view of a vortex water flow accelerator showing my new design;
FIG. 2 is another perspective view thereof;
FIG. 3 is a front elevational view thereof, the rear elevational view being a mirror image of FIG. 3;
FIG. 4 is a left side view thereof;
FIG. 5 is a right side view thereof;
FIG. 6 is a top plan view thereof;
FIG. 7 is a bottom plan view thereof; and,
FIG. 8 is a schematic diagram of the vortex water flow accelerator in a position of use.
The broken lines in the figures are for the purposes of illustrating portions of the vortex water flow accelerator, which form no part of the claimed design.