Thanks so much. Very useful information, I’m slowly but surely starting to learn more and more about how it works.
Could you please share these tables, what confuses me is that mach speed is usually used above a certain speed, and gliders usually fly at a much lower speed. 100-250 km/h. It would be interesting if I could learn how you/you use these in a much slower moving aircraft.
Can you use minus values in most tables, for example -0.0002.
Or is it better to lower the general value: drag_coef_zero_lift = and change drag with drag_coef_zero_lift_mach_tab “plus” values. Which adds “drag”.
For example, if I now have a value from a Boeing 737-800 where according to the document I have, the value “CdO clean” is 0.021 and according to someone here, Cd0 is the same as drag_coef_zero_lift.
Then I think I could use the value in the document which is 0.021 and then use drag_coef_zero_lift_mach_tab and write partial minus values to match the other drag data I have. Example at 240 knots= 0.3628278Mach, I know the plane should decent with 1300-1350 feet. And with 0.021 the plane descends with 1500 or something. I now understand that I first should set the drag_coef_zero_lift_mach_tab to 0, collect data and then mach my numbers with the corect drag tabel? Or am I thinking wrong?
So should I start with as correct geometry data as possible, make all tables 0 then add all values I could get hold of, and then start applying Table to match the real numbers?
Are there any tables to be careful with or that are difficult to understand? Anyone you want to warn against messing with too much?
Once again, many thanks for the reply.