Why does a supersonic nozzle have a divergent shape?

AI Thread Summary
A supersonic nozzle has a divergent shape to facilitate the acceleration of gas beyond the speed of sound. As the flow transitions from subsonic to supersonic, the area must increase to maintain mass flow continuity while allowing for a decrease in pressure. This design enables the conversion of thermal energy into kinetic energy, which is crucial for achieving supersonic speeds. The relationship between area and velocity is governed by compressible flow dynamics, where a larger area at supersonic speeds results in higher velocities. Understanding this principle is essential for the design of efficient supersonic nozzles.
engg.ques
Messages
2
Reaction score
0
Nozzle:
Why for subsonic flow the cross-sectional area of nozzle decreases?
 
Engineering news on Phys.org
For an incompressible fluid with a single inlet and exit the conservation of mass equation simply reduces to volumetric flow in equals volumetric flow out. It is then immediately clear that with a change in area from the inlet to the outlet, there is a corresponding change in velocity.

The common sense answer is that if you want to put the same amount of constant density material through an area of different sizes, then you'll have to use different rates.

I consider the more confusing (and interesting) question to be why a supersonic nozzle is divergent.
 
Posted June 2024 - 15 years after starting this class. I have learned a whole lot. To get to the short course on making your stock car, late model, hobby stock E-mod handle, look at the index below. Read all posts on Roll Center, Jacking effect and Why does car drive straight to the wall when I gas it? Also read You really have two race cars. This will cover 90% of problems you have. Simply put, the car pushes going in and is loose coming out. You do not have enuff downforce on the right...
I'm trying to decide what size and type of galvanized steel I need for 2 cantilever extensions. The cantilever is 5 ft. The space between the two cantilever arms is a 17 ft Gap the center 7 ft of the 17 ft Gap we'll need to Bear approximately 17,000 lb spread evenly from the front of the cantilever to the back of the cantilever over 5 ft. I will put support beams across these cantilever arms to support the load evenly
Thread 'What's the most likely cause for this carbon seal crack?'
We have a molded carbon graphite seal that is used in an inline axial piston, variable displacement hydraulic pump. One of our customers reported that, when using the “A” parts in the past, they only needed to replace them due to normal wear. However, after switching to our parts, the replacement cycle seems to be much shorter due to “broken” or “cracked” failures. This issue was identified after hydraulic fluid leakage was observed. According to their records, the same problem has occurred...
Back
Top