If I had a non-rotating whirlpool, what equation can I use to calculate the inward changing water velocity based on the distance from the whirlpool?

I’m trying find an equation that if given a non-rotating whirlpool with some inward velocity of water at the mouth of the whirlpool. What will the velocity or acceleration of the water be at some changing distance from the whirlpool based on the mouth radius of the whirlpool?