I've been working on a spreadsheet to calculate some numbers that I'm interested in. One formula I'm using requires CM and assumes that it will be CMsub0.25

This is fine as long as I'm using section data generated by the Eppler code. Since I don't have access to much of that I'd like to include a conversion factor so the spreadsheet can work with data from a variety of sources. Anyone know what such a conversion formula might look like?

I've attached the spreadsheet with the example data from the B² web site where I got that part of the formula. If I used this as the test data I would not have noticed the error. Fortunately I used the N-9M and section data that was generated by Xfoil/profili. Using that data the twist prediction was off by a factor of 8.

This is fine as long as I'm using section data generated by the Eppler code. Since I don't have access to much of that I'd like to include a conversion factor so the spreadsheet can work with data from a variety of sources. Anyone know what such a conversion formula might look like?

I've attached the spreadsheet with the example data from the B² web site where I got that part of the formula. If I used this as the test data I would not have noticed the error. Fortunately I used the N-9M and section data that was generated by Xfoil/profili. Using that data the twist prediction was off by a factor of 8.

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