Thread: Vortex Generators?

Has anybody looked into "Vortex Generators"? The manufacturer claims that the VG's produce results in improved performance and control authority at low airspeeds and high angles of attack. Do you think that would work well to help the CT during landing? Micro Aerodynamics is one of the companies that make them. If these will work, maybe if several of us inquire about a kit made for our application, they would consider it.

This is their web address

http://www.microaero.com/

I would be curious to hear your thoughts on this subject.

Thanks

Jim

As I recall from my Aero engineering days the goal is to get the wing to stall from the root and work outwards. Then there is the high energy turbulent BL which separates at a higher pressure gradient than a laminar.

Supposedly those flat things on the leading edge are supposed to do that on the CT. IMO, with full flaps the transition from near-stall to full stall won't be affected much by vortex generation. I believe the 15 degree flap setting could benefit from VG's.

Then again, we were working with a Univac 1110 mainframe and punched cards for our fluid dynamics models.

Jim,

Interesting question. My thinking is that the CTSW has good control authority and performs well at extremely slow speeds. The good performance at very slow speeds is why the plane can be gusted into flying again after the pilot might think he has landed. When flying a CTSW it is highly desirable to maintain good control over airspeed, sink rate and pitch attitude as well as having a good sense of where the ground is. Not only do you need to perceive these things well you have to react in order to control them.

If I'm right in my thinking that the CT has a large envelope and high performance and therefore requires high proficiency as opposed to quirky behavior like dropping a wing or things that I would think vg's could address then they won't help.

It would be great if FD could chime in here, I for one would be very interested in their thinking.

never flown a ct, i fly a rans s7, the rans has no warning of stall...when you land you better have the right speed or it drops out from underneath you. you add vortex gen. and it lands close to a 152. i would not leave home without them. i have no idea if they would help a ct, but the maule company now installs them on their planes as standard equip. Maule is the ultimate short field gen aviation plane. the vortex gen do not effect cruise speed.....donk

I have them on my 182 also along with flap gap seals. The stall is around 42 kts compared to 49kts of the stock plane. We went up last weekend with a friend who is a CFI and were able to fly it at 24kts MCA. I was able to get it down to 29kts previously. The VG's really lower the speed but I've never flown it without them, so I can't tell how different it is. On a side note, the stall is very different to me. When it stalls now, it is a STALL where it usually mushed around the sky in any other Cessna's I flew. When my plane breaks, you KNOW it and can lose some altitude. You may be able to see them in this picture on the leading edges of the upper wing and on the rudder. On the horizontal stab, they're on the bottom.

John

PS Some people say it slows it down a few knots, but I can't tell. The VG's are kind of like a Powerflow exhaust system. Some people swear by them and others say it's "smoke and mirrors".

VG's usually work on most planes. Most people who have them seem to like them. Even jets have then sometimes to help the airflow. I even know people who put them on the horizontal stabilizer. For the most part you just need to decide if you can or can't live without them and in our case it might be iffy for a Letter of Approval. Our CT's are so clean compared to some aircraft we might see a slight hit on cruise.

I believe there would be a significant hit to cruise performance with only a small decrease in stall speed. Remember, the 182 wing is based on an NACA airfoil from the '40's. The CT airfoil looks to me like a super-critical type that would have it's advantages undone by adding VG's.

No longer a practicing aero guy, so this is opinion only.