Turbulence or turbulent flow is a fluid regime characterized by chaotic, stochastic property changes. Turbulence often affects ships, aeroplanes and space-ships. The Ancient vessel Destiny encountered turbulence when it performed an Aerobraking maneuver around a planet. (SGU: "Darkness")
Also, the Ancient Shuttle accompanying Destiny experienced severe turbulence when entering the atmosphere of an unstable planet while trying to find food and water for Destiny's crew. (SGU: "Aftermath")
Destiny also encountered turbulence again when it performed another Aerobraking maneuver to line up with a star in order to recharge. (SGU: "Blockade")