Talk:Stagnation pressure

I don't understand why the thermal form of stagnation pressure is presented here. Stagnation pressure is the pressure a moving fluid would have if it is stagnated or stopped. It is difficult to clearly communicate this in a formula that makes no reference to velocity. Stagnation pressure is constant in an eisentropic flow. $$P_s = P + \rho v^2$$ where $$P_s$$ is the stagnation pressure, $$P$$ is the pressure at a given velocity, $$\rho$$ is density and $$v$$ is velocity. Granted that any change in $$v$$ must be accompanied by a change in temperature $$T$$, but to someone that is un initiated in the art of fluid dynamics this is probably not obvious. This is especially true when working with an incompressible fluid such as water.

Adding heat to a moving gas at constant pressure and velocity reduces its density and stagnation pressure. Conversley cooling a moving gas at constant pressure and velocity has the oposite effect. US Patent 5,083,429describes a device that uses this effect to extract power. . —Preceding unsigned comment added by Commdweeb (talk • contribs) 13:55, 11 October 2006 (UTC)

It's not a good idea to merge stagnation pressure and ram pressure. They are different concepts. The point needs to be clarified, though, that stagnation pressure in an incompressible fluid and stagnation pressure in a compressible fluid are different. The latter is almost always expressed in terms of the Mach number. See any good book on compressible flow.Petwil (talk) 02:00, 25 January 2008 (UTC)


 * I removed the tags for the merger of ram pressure to here, since no reasons to do so are provided. Only a reason why not merge. Crowsnest (talk) 21:30, 21 April 2008 (UTC)

I don't understand why the article claims that total pressure is the same as stagnation pressure. The article on total pressure conflicts with that claim - it shows that total pressure is static pressure plus dynamic pressure PLUS an additional term - gravity head relative to some datum. These two articles are inconsistent with each other. I believe my edits have addressed the problem. Discostu5 (talk) 16:06, 26 April 2013 (UTC)Discostu5