To have an accurate prediction using Bernoulli's equation the fluid particles must follow a stream line. This means that the fluids follow the same predictable path that particle before it followed, so that the fluid motion can be easily predicted using dynamics. This is also known as laminar flow. If the fluid particles follow random paths instead of a similar path, it is called turbulent flow. Turbulent flow is considered chaos since it is very difficult to predict the fluid motion due to the fact that fluid particles don't appear to follow a particular stream line.