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 manukamin May 3, 2012 00:54

Hello

It is my intention to design a cascade of airfoils which represents its corresponding axial flow compressor.

What I want to know is what are the design inputs to be considered for this particular task. For example is it the outlet to inlet pressure rise ratio or it the rpm of the rotor or is it the axial velocity that is to be considered as my design input according to which I define parameters such as blade profile, spacing between blades etc.

Could someone please let me know how I have to approach and where I cold find the necessary literature?

Regards
Manu

 manukamin December 5, 2012 01:20

Hello

Well I got a lot of information on axial compressor design in a book named "Aircraft Engine Design" by J.D.Mattingly. I suggest you check it out as well.

 vicarious December 5, 2012 06:30

Quote:
 Originally Posted by manukamin (Post 358998) Hello It is my intention to design a cascade of airfoils which represents its corresponding axial flow compressor. What I want to know is what are the design inputs to be considered for this particular task. For example is it the outlet to inlet pressure rise ratio or it the rpm of the rotor or is it the axial velocity that is to be considered as my design input according to which I define parameters such as blade profile, spacing between blades etc. Could someone please let me know how I have to approach and where I cold find the necessary literature? Regards Manu
Hello,
For simulating an axial compressor you need to have the Aero-thermodynamic properties such as compressor map which represent the head and flow coefficient so you can calculate the inlet and outlet, pressure and the mass flow rate, and the blade profiles. You can easily find many test stages and their setup and use it. The inlet total and static pressure is needed to be set as inlet boundary, the outlet static pressure is needed to be set as outlet boundary. the rotor speed is needed to be set as the rotor passage revolution. With these parameters you will be able to do the job.

Regards.

 manukamin December 19, 2012 01:03

Hi Vicarious

Thanks a lot for the reply.

Manu

 manukamin December 19, 2012 01:14

But then again, another doubt arises. How can you impose a pressure at the outlet as a boundary. Don't you think I should allow the flow to develop and see what pressure is attained rather then impose a pressure at the outlet?

 vicarious December 19, 2012 15:42

There is not any alternative and appropriate boundary other than pressure for such devices I'm afraid. Compressors work at a specific pressure rise corresponding to its mass flow. So in theory you achieve a pressure rise that you cannot achieve in numerical solution or experiment. You use these values to initialize your solution and reach close to them by solution. Other boundary definition will result in wrong answer or will not work.

Regards.

 manukamin December 20, 2012 00:25

Oh I see. Thanks for the response.

Regards,
Manu

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