Do right angles reduce flow

Answer 1

Yes, right angles reduce "flow", or more properly, rate of flow, which is measured by the volume of the fluid which goes through a particular surface area per unit of time. The quickest flow rate on a horizontal plane without any other influences is a straight line. If the fluid has to turn a corner, the fluid at the outside of a corner has to travel faster than the middle, because it is traveling a greater distance, and the fluid at the inside of the corner has to travel more slowly, because it is traveling a shorter distance. The different speeds create turbulence, and the rate of flow is slowed.

A simple analogy is watching a junior high school marching band try to turn a corner. The person on the inside has to take shorter steps, the person in the middle should continue to take the same size steps, and the person on the outside has to take longer steps. It's unusual for a junior high band to get the size of their steps just right depending on their position, so you'll see some kids scrambling, some kids stopping and waiting for the rest of the line to catch up. . . and the whole band has to slow down while everything is sorted out.