Lockheed Boston / Ventura wing slots

[dragonlance_HR]

Is there any schematic how they work? if I'm understanding what I see in the photos, the bottom part is moveable and the bottom opening size varies, plus there is the anti-ice rubber boot.
TIA
Vedran

 

[mjfur]

Slots do not move. They are permanent openings in the wing to allow air to flow thru to lower the stall speed.

 

[Wurger]

IIRC there isn't any movable part for the slot type. These are the fixed ones and work like those attached outside. The larger angle of attack of the wing and smaller speed the more of the air runs into the slot going out at the tops and causing increasing of the lift.

 

[dragonlance_HR]

I am not sure if the bottom opening isn't adjustable somehow. Sometimes on PV-1 the bottom opening looks big and sometimes it looks small.

 

[SaparotRob]

Not germane to the conversation but those are great photos.

 

[Wurger]

I am not sure if the bottom opening isn't adjustable somehow. Sometimes on PV-1 the bottom opening looks big and sometimes it looks small.View attachment 845703View attachment 845699View attachment 845701View attachment 845702

These bottom openings weren't adjustable rather. It is a light trick. The colours there and the angle the images were taken with make this. The areas around the openings and the inner surfaces of the slots were painted black. Also because there were the inspection/accessing hatches. You may notice them in the enlarged shot of your first image posted above and others below here. In other words the black rectangles at the bottom were a kind of the techical markings/ stenciling making easier to notice the openings. However the factory way of making the slots could have varied in order to make them simpler in construction and attaching for the the different batches of the PV-1. In these shots you may notice these were made in two versions.

the pic source: the net.

 

[dragonlance_HR]

Thank you Wurger!
Your 4th photo clearly shows the deicing rubber boots for the slots (including fixing profiles as per the erection manual) and the 5th photo shows the slots sans the boots. We are making progress!
Cheers,
Vedran

 

[Wurger]

 

[dragonlance_HR]

Sorry to reopen the old thread, but this popped on britmodeller today.

THE ROYAL AIR FORCE IN BRITAIN 1940-1945

Hudson. This looks like a rubber strip to me. Anti-icing?

 

[skyking1]

Since you bumped it I will add an explanation on the aerodynamic function of those slots.
The ideal wing shape has some washout, a lessening of the angle of incidence towards the tips. This keeps the plane controllable into the stall, as it stalls the inboard sections but the tips with the ailerons are still flying. You kept a modicum of roll control into the developing stall. Eventually the whole wing will stall, but it is a much more controllable situation.
The Hudson looks like a straight wing. The un-slotted version would have a very bad tendency to roll hard as one wing stalled before the other in various conditions. That sea of air we fly in is rarely smooth like glass.
As the angle of attack increases, some of the air will make it's way through the slot and keep some flow attached over the ailerons. Keeps that roll control into the stall.