Fluid flow and inertial forces in black hole space times

TL;DR

This paper analyzes the behavior of centrifugal forces in fluid flows around black holes, revealing that force reversal is mainly influenced by azimuthal velocity and occurs near the black hole at specific radii.

Contribution

It provides a detailed analysis of inertial forces in black hole spacetimes, highlighting the conditions under which centrifugal force reverses due to fluid motion.

Findings

Centrifugal force reversal depends on azimuthal velocity dominance.

Reversal occurs mainly between 2m and 3m radius.

The boundary conditions influence the radius of force reversal.

Abstract

We discuss the nature of the radial and azimuthal components of centrifugal force associated with fluid flows in the equatorial plane of black hole space times. The equations of motion are solved for the radial and azimuthal components of the 3-velocity V^i which are then used in evaluating the nature of the various components of inertial accelerations. It is shown that the reversal of centrifugal force is governed mainly by the dominance of the azimuthal velocity and the reversal occurs for r, mostly at 2m <~ r <~ 3m, depending upon the boundary condition.