Vic,
The thoughts I placed to deciding what I wanted or call it needed as far as LE devices in my build.
Yes I want to be able to truly slow the plane down, BUT more important in my aging mind was to make the plane "spin proof".
Spin proof is really making a plane stall resistant.
Vortex generators help with keeping the flow attached to the upper surface but from what I see there is little rhyme or reason they are placed where they are. On any particular plane I see them way up front or back about 20% of the airfoil. They are mounted helter skelter at different spacing and angles. I hear they work fine but many pilots say they can not tell any difference.
Slots, allot of work for some but no great gain. Many airplanes that came with slots, they get skinned over and the plane performs better.
Slats, they do seem to work well. There are quite a few versions that each have there own benefits and take aways. But they all offer a substantial reduction to "loss of lift"
The add on slats as used in the Mackey design work well. Personally a little more tweaking of pivot location and they will close fully under low lift conditions, "cruise". These slats came to being long before a 20YO on a computer could analyze them.
The Handly Page slats as on a Helio are an engineering marvel. I like what I have designed but I fully expect these are not optimized as to their opening and closing. More complex to build but for a few of us, they will be worth it. Again a 20YO can probably write the code and get them optimized in short order, we grown ups throw darts and build what we feel is best.
Even if any slots or slats are not optimized they will be there when they are needed.
The myth the plane needs to be at a stupid steep deck angle for LE devices to work is not necessarily true.
For one, when flaps are deployed, you can place an imaginary line from the leading edge to the trailing edge of the flap. This line is your camber line which increases your AOA of the airfoil. The deck of the fuselage may not get much steeper but geometrically the wing does.
This is what will bring the slats, or slots for that matter, "into play" at usable flight parameters.
For me, I am looking for my wing to both "save my azz" as well as the low speed performance gain they offer.
The thoughts I placed to deciding what I wanted or call it needed as far as LE devices in my build.
Yes I want to be able to truly slow the plane down, BUT more important in my aging mind was to make the plane "spin proof".
Spin proof is really making a plane stall resistant.
Vortex generators help with keeping the flow attached to the upper surface but from what I see there is little rhyme or reason they are placed where they are. On any particular plane I see them way up front or back about 20% of the airfoil. They are mounted helter skelter at different spacing and angles. I hear they work fine but many pilots say they can not tell any difference.
Slots, allot of work for some but no great gain. Many airplanes that came with slots, they get skinned over and the plane performs better.
Slats, they do seem to work well. There are quite a few versions that each have there own benefits and take aways. But they all offer a substantial reduction to "loss of lift"
The add on slats as used in the Mackey design work well. Personally a little more tweaking of pivot location and they will close fully under low lift conditions, "cruise". These slats came to being long before a 20YO on a computer could analyze them.
The Handly Page slats as on a Helio are an engineering marvel. I like what I have designed but I fully expect these are not optimized as to their opening and closing. More complex to build but for a few of us, they will be worth it. Again a 20YO can probably write the code and get them optimized in short order, we grown ups throw darts and build what we feel is best.
Even if any slots or slats are not optimized they will be there when they are needed.
The myth the plane needs to be at a stupid steep deck angle for LE devices to work is not necessarily true.
For one, when flaps are deployed, you can place an imaginary line from the leading edge to the trailing edge of the flap. This line is your camber line which increases your AOA of the airfoil. The deck of the fuselage may not get much steeper but geometrically the wing does.
This is what will bring the slats, or slots for that matter, "into play" at usable flight parameters.
For me, I am looking for my wing to both "save my azz" as well as the low speed performance gain they offer.