[adit_YA]

Hello everyone,

I am trying to make a MATLAB code to design a 2D planar nozzle with uniform outflow for use in a wind tunnel. I am using the method of characteristics approach and following the book "Gas Dynamics Vol II by Maurice J. Zucrow and Joe D. Hoffman". I have made the initial value line and its extension. However, I am facing a lot of difficulties in generating the initial expansion curve or finding particular theta and the corresponding kernel region for a desired design Mach Number.

Also, Zucrow talks about mass flow rate conservation to generate the straightening section which I am quite confused on how to incorporate into the code.

I am still looking into Cory Dodson's code on GitHub https://github.com/corydodson/NozzleDesign. Although when I run the code, singularities show up and I am still trying to debug it. Are there any books, resources, codes (MATLAB) which uses Zucrow's method and talks about the design in detail ?

Any help is appreciated! Thank you!

[FMDenaro]

Originally Posted by adit_YA

Hello everyone,

I am trying to make a MATLAB code to design a 2D planar nozzle with uniform outflow for use in a wind tunnel. I am using the method of characteristics approach and following the book "Gas Dynamics Vol II by Maurice J. Zucrow and Joe D. Hoffman". I have made the initial value line and its extension. However, I am facing a lot of difficulties in generating the initial expansion curve or finding particular theta and the corresponding kernel region for a desired design Mach Number.

Also, Zucrow talks about mass flow rate conservation to generate the straightening section which I am quite confused on how to incorporate into the code.

I am still looking into Cory Dodson's code on GitHub https://github.com/corydodson/NozzleDesign. Although when I run the code, singularities show up and I am still trying to debug it. Are there any books, resources, codes (MATLAB) which uses Zucrow's method and talks about the design in detail ?

Any help is appreciated! Thank you!

Not sure if I remember well, in the Zucrow textbook there is the Fortran code, isn't it?

[adit_YA]

Originally Posted by FMDenaro

Not sure if I remember well, in the Zucrow textbook there is the Fortran code, isn't it?

There is, but none of the codes talks about how to adapt the inflection point angle(Theta Max) for a desired design mach number.
I believe I need to iterate over a set of theta angles, generating the corresponding kernel region for each theta and check whether the desired mach number at the axis has been reached or not for that value of Theta.

[LuckyTran]

Yes of course you need to iterate something to get what you desire, that's what "design" means. Otherwise, there wouldn't be any need to design something, you would just click the "Add to cart" button

[FMDenaro]

Originally Posted by adit_YA

There is, but none of the codes talks about how to adapt the inflection point angle(Theta Max) for a desired design mach number.
I believe I need to iterate over a set of theta angles, generating the corresponding kernel region for each theta and check whether the desired mach number at the axis has been reached or not for that value of Theta.

Despite the fact that for expansion flows you can use Riemann invariants to get the exact solution, there is always an equation that need to be solved by iteration method to get the solution. This is what happens for unsteady flows as well as for steady flows for both direct and inverse problems.