Originally posted by F4UDOA:
BadBoy,
If you reference the NACA report on Lift Coefficients you can find Cl of most major fighter types with and without flaps.
BTW, any new charts or graphs related to actual flight numbers or AH would be appreciated. Great work!
Later F4UDOA
F4UDOA
Thank you for the link to that NACA report, I hadn't seen it before. I've just finished reading and grading my own student's research papers and thought I couldn't face another single report this year, but I was mistaken, it made an interesting change from the Sunday morning newspapers <g>.
I assume you posted the link because you believe that the report supports your contention for lower values of Clmax than those quoted earlier in the thread, I don't agree that the report does that. What that report does do very well, is to show how various design features influence the value of Clmax, which is invaluable if you want to design, or improve an aircraft. What it doesn't do well, is to relate their test results to actual flight conditions. The report concludes by saying that they lacked the data required to estimate the contribution of several important factors to the lift coefficient. They also show a pair of curves that indicate lift coefficients as much as 35% higher under true flight conditions as opposed to their tests. They also openly claim to have made only "rough approximations" in accounting for the discrepancies. Lastly, they make absolutely no mention of other factors that I believe are important, and can significantly increase the lift, which means that while the report represents an excellent piece of work for its intended purpose, it has little value for performance prediction. The values I quoted come from USAAF flight test data and generally show maximum lift coefficients somewhat higher than airfoil data quoted in other sources. This is often the case because in flight there are factors that act to increase the lift and reduce the stall speeds beyond the values obtained in wind tunnel tests.
Having said that, I generally prefer to let the simulation developers worry about matching the performance of the aircraft they model to their real world counterparts. I prefer to confine my efforts to revealing the performance of the aircraft as they are modelled in the simulation, after all, that is what really counts when you fly online. I'm going to prepare an analysis for some of my favourites first, the P-51, the Spitfire and P-38 are very high on the list. In fact I have already done an EM diagram overlay for the AH and AW P-51D, but I'm surprised with the results and I need to discuss it with others before going public.
Badboy
