Laminar—or streamline—flow moves through a system in thin cylindrical layers of liquid flowing in fashion. This type of flow will have little if any (swirling or eddying) in it. Laminar flow usually exists at low flow rates. As flow rates increase, the laminar flow pattern changes into a flow pattern. Turbulent flow is the random movement or mixing of fluids. Once the turbulent flow is initiated, molecular activity speeds up until the fluid is uniformly turbulent.