Is Total Pressure Constant at the Same Altitude for Any Moving Flow?

[su214]

total pressure , I'm confused !

hello :)
i'm new here ...
i'm confused in poits regards pressure
now please correct me if I'm wrong...
1-static pressure is equal to the total pressure if the gas is static (V=0)
2- total pressure is always equal or bigger than the static pressure
3-as the velocity increases the static pressure decrease

if these statements are correct then

1- is the ambient pressure is equal to total pressure and the total pressure is constant at same altitude for any given moving flow
-ex:at sea level-?

2-if the above statement is correct ,then in case of increasing of fluid velocity will its static pressure will equal zero at certain velocity ?

3-
here :
http://img801.imageshack.us/img801/7098/29329605.jpg"
the underlined lines confused me very much the author say that " the static P and T remain UNCHANGED "??
and the stagnation reference depend on the frame of reference?
i can't understand the underline lines...

 

[RandomGuy88]

Total pressure is the sum of static pressure and dynamic pressure, where dynamic pressure is proportional to V^2. Since velocity is dependent on the reference frame so is dynamic pressure and therefore total pressure. The static pressure remains unchanged because it is dependent on the local atmospheric conditions which do not depend on your frame of reference. So if two people are standing next to each they both feel the same static pressure but if one person starts to run forward they feel an additional pressure on their front side. The pressure they feel is the total pressure which is the local static pressure plus the dynamic pressure based on their velocity. The person standing still only feels local static pressure which in their case is the total pressure because they are not moving relative to the air.

To answer this question:
"in case of increasing of fluid velocity will its static pressure will equal zero at certain velocity ?"

No, because as the fluid velocity increases it will approach Mach 1 where shockwaves will form and static pressure increases across a shock.