Increasing Fuse length and Cof G
04-24-2016, 04:50 AM
#51
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da Rock has it right.
although the balance point changes it s the influence that the tail moment has on the CG that is changing how the glider flies .the tail moment's effect on attitude work through the CG the pane's attitude is dependent on where the CG is, in relation to the center of lit created by the wing's airfoil. the CG isn't necessarily moving, the center of lift is moving in relation to the CG., so it affects the attitude the plane has in relation to the balance between lift and the influence that the tail surfaces have on steering the lift produced. that produces level flight. when that balance is equal, it produces level flight, if that balance is biased rearward or forward, lift overtakes steering and the planes attitude is upset, making it do loops,or dives. in either case the CG doesn't change, the distance between center of lift and CG is what changes. when that changes, it changes the influence the tail surfaces have on the plane's attitude in flight.
although the balance point changes it s the influence that the tail moment has on the CG that is changing how the glider flies .the tail moment's effect on attitude work through the CG the pane's attitude is dependent on where the CG is, in relation to the center of lit created by the wing's airfoil. the CG isn't necessarily moving, the center of lift is moving in relation to the CG., so it affects the attitude the plane has in relation to the balance between lift and the influence that the tail surfaces have on steering the lift produced. that produces level flight. when that balance is equal, it produces level flight, if that balance is biased rearward or forward, lift overtakes steering and the planes attitude is upset, making it do loops,or dives. in either case the CG doesn't change, the distance between center of lift and CG is what changes. when that changes, it changes the influence the tail surfaces have on the plane's attitude in flight.
04-25-2016, 04:28 AM
#52
My Feedback: (41)
C/g goes with wing
da Rock has it right.
although the balance point changes it s the influence that the tail moment has on the CG that is changing how the glider flies .the tail moment's effect on attitude work through the CG the pane's attitude is dependent on where the CG is, in relation to the center of lit created by the wing's airfoil. the CG isn't necessarily moving, the center of lift is moving in relation to the CG., so it affects the attitude the plane has in relation to the balance between lift and the influence that the tail surfaces have on steering the lift produced. that produces level flight. when that balance is equal, it produces level flight, if that balance is biased rearward or forward, lift overtakes steering and the planes attitude is upset, making it do loops,or dives. in either case the CG doesn't change, the distance between center of lift and CG is what changes. when that changes, it changes the influence the tail surfaces have on the plane's attitude in flight.
although the balance point changes it s the influence that the tail moment has on the CG that is changing how the glider flies .the tail moment's effect on attitude work through the CG the pane's attitude is dependent on where the CG is, in relation to the center of lit created by the wing's airfoil. the CG isn't necessarily moving, the center of lift is moving in relation to the CG., so it affects the attitude the plane has in relation to the balance between lift and the influence that the tail surfaces have on steering the lift produced. that produces level flight. when that balance is equal, it produces level flight, if that balance is biased rearward or forward, lift overtakes steering and the planes attitude is upset, making it do loops,or dives. in either case the CG doesn't change, the distance between center of lift and CG is what changes. when that changes, it changes the influence the tail surfaces have on the plane's attitude in flight.
GOT THAT PART RIGHT. C/G IS LOCATED" ON WING."
FLYING WING STILL HAS C/G ..
COME ON GUYS !!!
CAN FIND, C/G OF ANY PLANE, IN 3 MINUTES WITH RULER.
04-26-2016, 03:54 AM
#53
Senior Member
As for flying wings having a CG, yup. They also have pitch stability that's controlled by something else they have, an elevator that's sized to suit the requirements. And the CG range is also figured out beforehand. It's so narrow the actively flying full scale ones were designed with that overriding thought. For example, the bomb load of the B1 was penciled in exactly on the spanwise CG so the CG wouldn't shift when those bombs were dropped. And that took some head scratching because the fuel tanks were in the way. They couldn't be placed very far from the CG Scl either. But before they started cutting the parts out, they very carefully worked out what size the tail volume would be. And then tested that in the wind tunnel. Tail volume is the size of the tail and how far aft of the CG it's going to be. How far aft or forward the volume is would be called tail moment. It's a lot easier to measure when there isn't a fuselage, btw.
Last edited by da Rock; 04-26-2016 at 07:34 AM.
04-26-2016, 06:33 AM
#54
Senior Member
The CG affects and is affected by lots of other things. The air balance of my Corsair truly wasn't as important to begin with as it's ground balance. If you can't get it into the air, how it flies really doesn't matter, does it.
Where the CG is "on the wing" often isn't that important. The layout above came from R/C Model Aircraft Design, by Andy Lennon. It shows where the CG actually is, the one of many that is used to figure out where the foot print of the tires need to be for successful ground handling.
Notice the top blueprint refers to the "forward most" CG. The lower diagram shows the "aftmost CG". Notice also the CGs shown don't happen to be inside the wing at all. What is usually talked about in our ARF models assembly notes is actually a balance point. It's absolutely positively great info to have, but knowing the full range of safe CGs you get from running the formula twice gives you far more than twice as much info.
It takes very little "extra" time to measure both the wing and the tail. What you get actually fits the airplane the way it's laid out.
Being able to fix the Corsair's ground handling without going outside it's pitch stability envelope was one result of using the correct formulas. Knowing to adjust the elevator throws to make the maiden flight easier on the pilot was a really good extra.
Where the CG is "on the wing" often isn't that important. The layout above came from R/C Model Aircraft Design, by Andy Lennon. It shows where the CG actually is, the one of many that is used to figure out where the foot print of the tires need to be for successful ground handling.
Notice the top blueprint refers to the "forward most" CG. The lower diagram shows the "aftmost CG". Notice also the CGs shown don't happen to be inside the wing at all. What is usually talked about in our ARF models assembly notes is actually a balance point. It's absolutely positively great info to have, but knowing the full range of safe CGs you get from running the formula twice gives you far more than twice as much info.
It takes very little "extra" time to measure both the wing and the tail. What you get actually fits the airplane the way it's laid out.
Being able to fix the Corsair's ground handling without going outside it's pitch stability envelope was one result of using the correct formulas. Knowing to adjust the elevator throws to make the maiden flight easier on the pilot was a really good extra.
Last edited by da Rock; 04-26-2016 at 06:38 AM.
04-26-2016, 06:37 AM
#55
Senior Member
04-26-2016, 07:31 AM
#56
Senior Member
