Originally Posted by
Dev One
Not sure FS adds any drag with oil cooler or cowl flaps, but you can have an auto spoiler; I tried one that deployed at about less than 1/3 rd throttle, but it sounds as if your model is too slippery for that. I have found that modifying the slope & left/right position of the normal flight range part of the Cl vs Alpha & the slope of the same alpha range of the Cd vs alpha graphs not only affect the amount of trim needed over the speed range but also the drag. With a prop model I've also heavily modified the prop efficiency curves so that they avalanche just above the J value achieved at max speed in level flight, this also can apply drag when throttle is closed, but care is needed.
HTH
Keith
Two examples of use of the prop efficiency curves; Dave Molyneaux's DH 83 Fox Moth over at Flightsim & my Miles M3B Falcon Six over in the cbfsim library. To see the curves though you need to open the air file with Aircraft Airfile Manager, AirEd only shows it in tabular form.
On my WIP dragonfly I'm playing with the Cl & Cd curves, but Dave Molyneaux's Avro Avian uses a similar modification.
Can't find offhand the mathematical definition of drag (Cd), but my failing memory thinks it something like Cl squared in the equation.
K