Tinbuzzard
Member
I'm looking for information on estimating the actuation pushrod loads for a fairly large single-slotted flap on my Tinbuzzard project. Along with that, would aerodynamic loads on this type of flap tend to act in one direction only, or could the reverse happen? IE, would the airloads pushing on the flap always try to retract it , extend it, or even reverse at some point during deployment? My flaps are single pivot as illustrated below, and similar in size and deployment geometry to those of a Beechcraft Musketeer. I know that there are a lot of factors acting here; I just don't want to over (or under) design the actuating mechanism. I have the option of a motorized chain driven torque tube, or a manual Johnson bar and pushrod set-up back to the same TT.
General overview of my installation. Each outer wing panel has a 7.5 ft. span flap that has a maximum extension of 34 degrees as shown here. Flap and wing are tapered which doesn't show well from this angle. Flap root chord measured along the flat bottom is 20", the outboard end is 14". Flap chord is 30% of the wing chord. The pushrods shown here aren't the main actuator at the root end, these just attach to a torque tube inside the wing to ensure that the flap deploys evenly.
View of left wing outer panel root flap airfoil and pivot geometry. This inboard pivot is 5" behind the flap LE measured along the bottom surface, and 5" below that bottom surface, under the flap quarter chord point as are the rest of the pivot points. Actuator pushrod attach point is 8.5" from the pivot below.
Left flap fully deployed showing main pushrod and the torque tube that runs through the center section to connect both flaps at the upper right. Twisting this TT with one hand fairly easily deploys and retracts one flap in the shop. I'm just worried about what airloads to expect, and thus what my maximum flap deployment speed might be. Any suggestions or advice appreciated!
General overview of my installation. Each outer wing panel has a 7.5 ft. span flap that has a maximum extension of 34 degrees as shown here. Flap and wing are tapered which doesn't show well from this angle. Flap root chord measured along the flat bottom is 20", the outboard end is 14". Flap chord is 30% of the wing chord. The pushrods shown here aren't the main actuator at the root end, these just attach to a torque tube inside the wing to ensure that the flap deploys evenly.
View of left wing outer panel root flap airfoil and pivot geometry. This inboard pivot is 5" behind the flap LE measured along the bottom surface, and 5" below that bottom surface, under the flap quarter chord point as are the rest of the pivot points. Actuator pushrod attach point is 8.5" from the pivot below.
Left flap fully deployed showing main pushrod and the torque tube that runs through the center section to connect both flaps at the upper right. Twisting this TT with one hand fairly easily deploys and retracts one flap in the shop. I'm just worried about what airloads to expect, and thus what my maximum flap deployment speed might be. Any suggestions or advice appreciated!
