sonic section before and after a shock !!
Hi every body
A sonic area in a CD nozzle can only exist when M=1 . It is the throat of the nozzle . When M=1 , we have a shock .
Imagine together that we have a normal shock NS just before the exit of the nozzle . My question is :
Is it true to say that we have a sonic throat upstream NS , it 's area is A1* ? ( with A1* = At , At is the throat of the nozzle )
Is it true to say that we have a sonic throat downstream NS , it 's area is A2* ?
At my opinion , we can only talk about a sonic area A* exactly where the normal shock takes place ( not before , not after NS) .
Thanks you for help , it seems that i am confused
Best Answer
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rahkumar Forum Coordinator
Hello,
To add to Kalyan's comment... * is an imaginary condition which would be useful for calculations. It is an imaginary condition where the conditions are adiabatically brought to Mach 1 and these can be anywhere in the flowfield. It also serves as a comparison to the actual conditions at that particular point in the flowfield.
Answers
Hello,
If there is a normal shock in the diffuser section of the CD nozzle:
I hope this helps.
Thanks,
Kalyan
Hello,
To add to Kalyan's comment... * is an imaginary condition which would be useful for calculations. It is an imaginary condition where the conditions are adiabatically brought to Mach 1 and these can be anywhere in the flowfield. It also serves as a comparison to the actual conditions at that particular point in the flowfield.