cape.dkit.dbll: Aerodynamic line load DataKits

This module provides customizations of cape.dkit.rdb that are especially useful for launch vehicle line load databases. The force & moment coefficient names follow common missile naming conventions:

Name	Symbol	Description
CA	\(C_A\)	Axial force
CY	\(C_Y\)	Side force
CN	\(C_N\)	Normal force
CLL	\(C_\ell\)	Rolling moment
CLM	\(C_m\)	Pitching moment
CLN	\(C_n\)	Yawing moment

Line loads are typically defined for the force coefficients, and the standard for these is to have dCN as a column name, which actually represents the value

\[\frac{\Delta C_N}{\Delta x/L_\mathit{ref}\]

In the limit of finer slices, this becomes \(\mathrm{d}C_N/\mathrm{d}x/L_\mathit{ref}\). In other words, the primary data is the derivative of a force coefficient with respect to the non-dimensional x-coordinate.