Hello everybody, It is normally said that fluid flow in a larger diameter pipe is easier (less energy losses) than in a smaller diameter pipe. This indeed appears to be true in relatively high flowrate applications however, I'm struggling to understand why drinking from a normal straw (small diameter) is much easier than drinking from say a 1" diameter pipe (large diameter). The only explanation I could come up with is that even though fluid through a smaller pipe will have higher velocity (given the same flowrate) in comparison to a larger pipe however, it will also be exposed to less area and thus, lower losses due to friction. Conversely, as flowrate increases the flow through the smaller pipe will become turbulent earlier than the larger pipe due to the higher velocity and thus more energy losses will result whilst the larger diameter pipe will maintain a laminar flow for higher flowrates. I don't know whether I'm right and I would appreciate it if someone could sheds some light on this. I hope my question is clear. Thanks in advance.