Knudsen number off by a factor of 2

[johodges]

Describe the bug
I was looking at the tech guide to better understand how we are predicting deposition. The guide defines the Knudsen number as:

Kn = lambda/radius

But in the code Kn is calculated by dividing by the diameter:

Wall line 1584: KN = KN_FAC/SM%THERMOPHORETIC_DIAMETER
Wall line 1589: KN = KN_FAC/SM%MEAN_DIAMETER
Wall line 1595: KN = KN_FAC/SM%MEAN_DIAMETER

Jason and I discussed this a few weeks ago and he indicate the following in an email. We have not had a chance to fix it yet, so adding this issue so it does not get lost.

Email from Jason

Good catch.

I had meant to account for that with KN_FAC.

Kn = lambda/r = 2 lambda / d

lambda = mu sqrt (1/2 pi/(rho P))

so KN_FAC should be 2 * lambda = mu sqrt (2 pi / (rho P)) but in the source it is now the ½.

Looking at the revision history KN_FAC was correct until about 6.7.6. Probably not thinking and while adding condensation just saw I had 2 rather than 1/2 in the square root for lambda and forgot the diameter correction (or Amy had reviewed the source and asked why and I forgot the diameter thing). So can return this back and fix the verification cases and should add a comment in the source to note that KN_FAC includes the factor of two for diameter.

[drjfloyd]

Fixed the source and think I got all the verification results fixed as well.