# Linearization of 5MW with Individual Pitch angles

**URL:** <https://forums.nlr.gov/t/linearization-of-5mw-with-individual-pitch-angles/669>\
**Category:** Computer-Aided Engineering Software Tools\
**Created:** [April 25, 2013, 10:30am UTC](https://forums.nlr.gov/t/linearization-of-5mw-with-individual-pitch-angles/669 "2013-04-25T10:30:16Z")\
**Posts on this page:** 1\
**Showing post:** 8

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**Author:** ![Jason.Jonkman](https://dub1.discourse-cdn.com/nrel/user_avatar/forums.nlr.gov/jason.jonkman/32/3086_2.png) [@Jason.Jonkman](https://forums.nlr.gov/u/Jason.Jonkman)\
**Post date:** [June 3, 2013, 1:21pm UTC](https://forums.nlr.gov/t/linearization-of-5mw-with-individual-pitch-angles/669/8 "2013-06-03T13:21:49Z")

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Dear Rannam,

I can’t think of a good reference that explains “aerodynamic stiffness.”

It is a bit peculiar to me that the stiffness matrix is not symmetric. This may be a result of the way the quasi-steady induction is recalculated with every perturbation in the linaerization process (and may not be realistic). In some cases, it is more accurate to assume a frozen wake during linearization–see, for example, the forum topic found here: [Gain Scheduling](http://forums.nlr.gov/t/gain-scheduling/286/1). I suggest you see if your linearization results are drastically different with frozen wake. If so, I would use the results with frozen wake.

Best regards,

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