# Design and Fabrication of a scaled down deLaval nozzle.

MdAsher
Greetings Everyone,
I am lookin forward to design a simple deLaval nozzle to achieve supersonic velocity in lab. I do not want to follow the cfd method or any other software method as of now. If someone could please guide me with calculating the various design parameters of the nozzle like inlet diameter, throat diameter, divergent diameter, cone angle and length of the nozzle.

Thank you.

## Answers and Replies

Gold Member
You can certainly calculate the area ratios in question using only some algebra but if you are wanting to determine the length and shape of that divergent section you'll need more detail than just "how long should it be" and you'll need at least rudimentary CFD. Without using a computer, doing the method of characteristics to determine these parameters would be daunting.

For example, what Mach number do you want to achieve? How large do you want it to be (i.e. what are the maximum dimensions you could tolerate)? Do you want to expand the flow to the exit as quickly (in space) as possible or do you want a longer, smoother nozzle? How accurate does your final Mach number have to be (i.e. do you need to account for the nozzle wall boundary layer in the design)? Do you want it to be 2D (rectangular exit) or axisymmeteic (circular exit)?

These are the kinds of bits of information you need to know if you want to design a nozzle for real. Now, you may be able to get away with just knowing the exit-to-throat area ratio and then machining anything that fits the bill, but we don't know that based on what you asked.

MdAsher
Thank you sir, would you please suggest me some books werin I can read indepth about nozzle design?

MdAsher
Thank you sir, it's really helpful. I hav started with Liepmann, starting to get a better picture.
Thank you sir