Turbulator Tape Placement Question

[John DeRosa Sky Soaring Chicago IL]

I just bought a DG-101. Already I am thinking of ways to improve the
performance. One thought I had was adding winglets but I have
discounted that for now because of the effort involved. Maybe later.

Another thought was turbulator tape. While my opinion (uneducated) is
that this will add to my L/D, the question of placement on the wing
leaves me stumped. Here are some questions;

1) Will it help? Let's get the basic questions out of the way first.
2) Where should it be placed? Would an oil test help in this
analysis?
3) What type of tape is best? I see Wings and Wheels has four types;
two sizes of 60 degree, one size of 90 degree and dimple tape.
4) Any idea of how much this might help? I know that this is the
toughest question of all.

I appreciate any responses.

Thanks, John

[Marc Ramsey]

John DeRosa Sky Soaring Chicago IL wrote:
> I just bought a DG-101. Already I am thinking of ways to improve the
> performance. One thought I had was adding winglets but I have
> discounted that for now because of the effort involved. Maybe later.
>
> Another thought was turbulator tape. While my opinion (uneducated) is
> that this will add to my L/D, the question of placement on the wing
> leaves me stumped. Here are some questions;

I owned a DG-101 for many years, and it performed quite well against
equivalent ships (LS-4, Pegase, ASW-19) without turbulators. I'm sure
there are those who have done it, however, it's not clear to me that the
airfoil was designed to work with them (unlike, say, the DG-300). The
things I found made a difference were installing S seals and mylar on
the ailerons, and sealing the pushrods at the wing roots with rubberized
fabric boots. If I remember correctly, mine also had mylar on the
rudder, a seal on the elevator pushrod, and a fabric tape seal on the
bottom of the elevator.

The other thing to do is move the CG back to around 20% forward of the
rear limit, it does make a difference. There is a mounting for a lead
weight at the end of the tail boom. DG also sells a brass tailwheel, I
had a local machine shop make one for me.

I'd skip the winglets, as the wing wasn't intended to take those sorts
of forces. DG does offer a kit which converts the wing tips to the
upswept style used on the 300, this allegedly will provide a measurable
increase in performance...

Marc

[Lars Peder Hansen]

Hi John,

After reading a lot about this and other performance increasing measures for
years (Johnson's flight test reports is one good source) I think that the
verdict is:

1) You get much higher performance / sweat droplet by sealing your glider
well (control surfaces, canopy, wing roots..)
2) Unless the airfoil *is designed for* turbolator tape, you will probably
do more harm than good. -And even if it is, you must get the placement
nailed right. Oil testing is the way to go here (or, for the lazy ones, ask
the designer ;-).

Have fun with the new ship,
Lars Peder


"John DeRosa Sky Soaring Chicago IL" > wrote in message
om...
> I just bought a DG-101. Already I am thinking of ways to improve the
> performance. One thought I had was adding winglets but I have
> discounted that for now because of the effort involved. Maybe later.
>
> Another thought was turbulator tape. While my opinion (uneducated) is
> that this will add to my L/D, the question of placement on the wing
> leaves me stumped. Here are some questions;
>
> 1) Will it help? Let's get the basic questions out of the way first.
> 2) Where should it be placed? Would an oil test help in this
> analysis?
> 3) What type of tape is best? I see Wings and Wheels has four types;
> two sizes of 60 degree, one size of 90 degree and dimple tape.
> 4) Any idea of how much this might help? I know that this is the
> toughest question of all.
>
> I appreciate any responses.
>
> Thanks, John