Updated heat transfer coefficient correlation parameters for horizontal and upward heat flow over PV panels.

[joshi994]

TYPE: Bug fix

KEYWORDS: PV panels, Correlations, Upward heat flow, Surface angle, Heat transfer coefficient, BEM (Building Energy Model).

SOURCE: Parag Joshi (Brookhaven National Laboratory)

DESCRIPTION OF CHANGES:
Problem:
A typographical mistake was identified within the correlations that evaluate heat transfer coefficient for the upward heat flow over PV panels in the Building Energy Model (BEM).

Solution:
The parameters have been modified following the correlation expressions provided in the literature.

ISSUE: For use when this PR closes an issue.
Fixes #123

LIST OF MODIFIED FILES: module_sf_bem.F

TESTS CONDUCTED:

1. No test has been conducted as the parameters seems to have very small or insignificant impact on the results. However, the tests can be performed with and without correcting the parameters to quantify the role.

Please refer to the equation J.2.2a (please see the attached screenshot) on page number 79 of the document below.
https://nvlpubs.nist.gov/nistpubs/Legacy/IR/nbsir83-2655.pdf

RELEASE NOTE: Parameters associated with the evaluation of heat transfer coefficient for the upward heat flow case are corrected.

[weiwangncar]

The regression test results:
Test Type | Expected | Received | Failed
= = = = = = = = = = = = = = = = = = = = = = = = = = = =
Number of Tests : 23 24
Number of Builds : 60 57
Number of Simulations : 158 150 0
Number of Comparisons : 95 86 0

Failed Simulations are: 
None
Which comparisons are not bit-for-bit: 
None

[weiwangncar]

@joshi994 Please hold off any update to this PR or any new PR, as we are going to update the regression tests in the next few weeks. Thanks!

[dudhia]

This PR is to master and should go to develop until we have a 4.6.1 branch