Hacker News new | past | comments | ask | show | jobs | submit login

I too would like another word, because I can tell you first hand that the confusion between total, static, and dynamic pressure is the source of many headaches amongst aerospace engineering students. It doesn't help that many textbooks often refer simply to "pressure" and expect the readers to intuit which they are referring to given the appropriate context.

A book will say:

"In low-speed aerodynamic flow, pressure is constant along a streamline"

and then one chapter later say

"Pressure changes with a change in velocity along a streamline"

The first references to total pressure while the second refers to static, but at first glance they seem contradictory.

However I would fully avoid the word "compression" since implies that we are squeezing more air into a fixed volume (a.k.a. an increase in density) which is NOT what is happening in a low-speed air flow. The definition of compression strictly applies to total pressure. Although most people don't learn this, since compression is often used in relation to stationary flows to begin with (such as in pressure vessels) where the dynamic pressure is 0, thus static pressure equals total pressure.




Guidelines | FAQ | Lists | API | Security | Legal | Apply to YC | Contact

Search: