Welcome to the ** Kline-Fogleman (KFm) Airfoils – Advanced Theory/Science ** discussion thread. The purpose of this thread is to try and. The simplicity and performance of the KF airfoil have made it popular in the Maker Trainer 2 and uses the KFm-2 (Kline-Fogelman model 2) airfoil design (a. The idea works but only with active automated re-configuration of the shape of the step(s) during flight. Further testing has shown that this airfoil.

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Does anyone have recommendations? I am not setting limits or kfk any rules but I think the logical way to do it is to discuss it and sort of work out candidates and broad objectives for comparison here. When the acceleration causes compression, air seems to handle that situation but when the acceleration involved entering a void, the air does not seem to like that iarfoil much. Kinda like my first wife Thus, a given airfoil can do certain things well, but do poorly in other areas.

Both wings exhibit good lift, and lift stays airfoll at lower airspeeds. If it is too far back especially the thing just won’t fly look on my YouTube channel for the original FPV Wing maiden! Originally Posted by Freddie B.

I had a can of spray adhesive in the cupboard and a quick test showed that it gave a very strong and quick bond when sprayed lightly over both surfaces without any bubbling of the paper. He was airffoil photo-retoucher by profession as well as a pilot and model airplane builder.

I’ve been thinking long and hard about the KFm and why it flies the way it does and I may have some answers.

KFm-4 airfoil for speed and stability

The main objective of the case study was to identify and outline a step schedule for the flight envelope of the UAV Pioneer using a stepped airfoil configuration at the same time applying active flow control to obtain enhanced aerodynamic performance over conventional NACA airfoil originally used and hence improve the flight performance characteristics like Range and Endurance of the aircraft.


All discussions and attachments are still in place in the parent thread, many of the figures, studies, and other attachments will be or have been moved to post 2 here. It is an important work!

Existing designs that can be bent to our purpose are easier than designing from scratch.

New Technology: Kline-Fogleman Airfoil Design

My friendly local printers put the drawings onto some A0 paper and it was on with the cutting…. As drag increases as a square of velocity it will, however, have a limited top end to the speed envelope. A Message From Mr. I will say at this point that KF wings work superbly for all powered models, they offer benefits in stabilitythey reduce stall and give smoother flights. As such, I am always on the lookout for new and innovative ways to build models that are both durable and perform well… KFm Airfoils The KF family of airfoils are nothing new.

What gives this airfoil its properties?

KFm-4 airfoil for speed and stability | Flite Test

The Ultimate Paper Airplane: I wonder how much having the KF airfoil wind tunnel tested in the correct configuration would cost. Images View all Images in thread. Post Your Answer Discard By clicking “Post Your Answer”, you acknowledge that you have read our updated terms of serviceprivacy policy and cookie policyand that your continued use of the website is subject to these policies. It is for everyone who airfpil interested in how Kline-Fogleman airfoil variants work, what they can and can’t do, and their best applications in our hobby.

Made from roughly 5. When there is a sudden bend the rules are that the lump of air is accelerated. And if you can’t If you build your own models and lack the ability to hot wire cut a wing then a layered KF wing is a must build.


By using this site, you agree to the Terms of Use and Privacy Policy. About 70 years ago a boy scout master saw airfoik a control line plane where the airfoil section was two perfect triangles and it worked fine with the expected curls and divergences around the edges at the leading at midsection and the trailing edge. Jack Images View all Images in thread Views: The basic KF sections all fly well, so I recommend it for all powered sport models.

I was out on Friday with a friend flying some FPV and these wings really are fantastic. Richard Kline To the RC community: After many experiments he was able to achieve kcm goal.

Nice build and maiden flight!!! Originally Posted by maguro. So, are we just going fkm talk about KF foils, or can we discuss the relative merits of the other common foils compared to KF?

This Kline-Fogleman is my next project. A typical plan is shown below. Red20RC on March 23, A Useless Geek asked: They concluded that the trapped vortex formed by a cavity or step could not be held in place without such active control.

Sign up using Facebook. All Others Bring Data. Why don’t they work for full sized aircraft?

CG on wings is airfiol. On a conventional airfoil the air must follow the sloping rear section of the airfoil, which at 0 degrees AoA is already at a degree slope away from the airstream. Post 4 has tony65x55’s explanation, in layman’s terms and with an accompanying figure, as to how he thinks the Kline-Fogelman airfoil works The parent thread can be read here: Hey Y’all, looks like the new thread is off to a great start!

With a wingspan of around mm each 5mm layer of foam board would therefore provide the correct step thickness.