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fluidmechanics		 What happens what the stagnation pressure in creases to a thermally chocked supersonic flow with shock at exit View All
I have a converging-diverging nozzle connected to a constant area duct which is heated. The stagnation temperature and stagnation pressure before the nozzle is constant and the flow is supersonic inside the duct. The duct exit is chocked. What happens when everything stays constant but the stagnation pressure increases or decreases? Where does shock move?
13 years ago - 3 weeks left to answer. - 1 response - Report Abuse
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Niel
 If the stagnation pressure decreases below the critical value where the flow is chocked [1] the speed down stream of the orifice will no longer be super sonic and the shock waves will disappear.

If stagnation pressure is increased the initial shock will still be at the throat. With a properly designed C-D nozzle [2] you can get supersonic speeds, but the flow is still choke and the initial shock wave is at the same place.

Niel Leon
engineering.com

13 years ago

Source: [1] http://en.wikipedia.org/wiki/Choked_flow

[2] http://en.wikipedia.org/wiki/Convergent-divergent_nozzle


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