Lift Augmentation Ratio for Hovercraft

Extract

When hovercraft were first introduced the lift or thrust augmentation ratio was often used as a measure of their effectiveness. Although this ratio has been used less with subsequent development, it continues to be quoted in some literature. It is defined as the ratio of the hovercraft lift to the lift that would be obtained if the curtain jet were used to produce direct lift by jet reaction. An analytical expression is determined in outline.