Inverse Magnus Effect Induced by Dilute Water Fog

TL;DR

This study experimentally investigates how dilute water fog influences the inverse Magnus effect on a spinning sphere, revealing that suspended droplets lower the flow conditions needed for the effect to occur.

Contribution

It demonstrates experimentally that water fog alters the inverse Magnus effect, reducing the critical Reynolds number and spin ratio for its onset.

Findings

Suspended water droplets significantly affect the inverse Magnus effect.

Flow with droplets lowers the critical Reynolds number.

Flow with droplets lowers the critical spin ratio.

Abstract

The inverse Magnus effect is a phenomenon in which a spinning sphere experiences a lift force opposite to the conventional Magnus effect. This effect is typically observed in the flow higher than a critical Reynolds number or spin ratio. We experimentally studied the inverse Magnus effect on a spinning sphere in a flow containing suspended micrometer size droplets. The lift force was measured by injecting droplets into a closed return wind tunnel. We investigated the threshold of the inverse Magnus effect for several types of dispersed droplets. Our results indicate that the flow with suspended water droplets significantly affects the onset of the inverse Magnus effect, causing a decrease in the critical Reynolds number and spin ratio.