Pressure ratio along blade span

DDG · January 13, 2019, 17:41

Hi everybody, I was trying to plot the pressure ratio vs the span normalized for a compressor rotor, the idea was to obtain a diagram as the one below. Does anybody know how it could be done? I tried to search in the default plot diagrams, but nothing seems to work

ghorrocks · January 13, 2019, 18:24

Please define what the pressure ratio versus span normalised actually means.

AtoHM · January 14, 2019, 05:11

I am not sure if there is a direct way. However, you can define a plane (e.g. at 50% span) and create a polyline where the plane and the blade interesect. Then, you can export whatever value you like (pressure) at the polyline-points. Then use something like Excel, Matlab, ... to calculate your pressure ratio and print it along the points.

Normalising the chord should not be too hard

Edit: I misread the question. Sorry.
You could create spanwise segments of your blade e.g. with a contour. With User Surfaces, you can get the single parts of the contour levels. Then extract an average pressure or something at each segment, normalize by the value you have in your pressure ratio and plot it versus the average span at that surface. You can get the data using the Table tool. For example "areaAvg(Pressure)@User Surface 1 / areaAvg(Pressure)@Inlet".
There might be an easier way though.

DDG · January 14, 2019, 19:23

Quote:

Originally Posted by AtoHM

I am not sure if there is a direct way. However, you can define a plane (e.g. at 50% span) and create a polyline where the plane and the blade interesect. Then, you can export whatever value you like (pressure) at the polyline-points. Then use something like Excel, Matlab, ... to calculate your pressure ratio and print it along the points.

Normalising the chord should not be too hard

Edit: I misread the question. Sorry.
You could create spanwise segments of your blade e.g. with a contour. With User Surfaces, you can get the single parts of the contour levels. Then extract an average pressure or something at each segment, normalize by the value you have in your pressure ratio and plot it versus the average span at that surface. You can get the data using the Table tool. For example "areaAvg(Pressure)@User Surface 1 / areaAvg(Pressure)@Inlet".
There might be an easier way though.

Yes, it worked.

Thank you a lot!

January 13, 2019, 18:24		#2
ghorrocks Super Moderator Glenn Horrocks Join Date: Mar 2009 Location: Sydney, Australia Posts: 17,703 Rep Power: 143	Please define what the pressure ratio versus span normalised actually means. __________________ Note: I do not answer CFD questions by PM. CFD questions should be posted on the forum.

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January 14, 2019, 05:11		#3
AtoHM Senior Member M Join Date: Dec 2017 Posts: 642 Rep Power: 12	I am not sure if there is a direct way. However, you can define a plane (e.g. at 50% span) and create a polyline where the plane and the blade interesect. Then, you can export whatever value you like (pressure) at the polyline-points. Then use something like Excel, Matlab, ... to calculate your pressure ratio and print it along the points. Normalising the chord should not be too hard Edit: I misread the question. Sorry. You could create spanwise segments of your blade e.g. with a contour. With User Surfaces, you can get the single parts of the contour levels. Then extract an average pressure or something at each segment, normalize by the value you have in your pressure ratio and plot it versus the average span at that surface. You can get the data using the Table tool. For example "areaAvg(Pressure)@User Surface 1 / areaAvg(Pressure)@Inlet". There might be an easier way though.