karoliina.t.salminen
Well-Known Member
I have been thinking about vtol concepts out of the box since they would have their place in aviation, a gap currently unfilled.
If we forget issues of combustion engines and consider an electric vtol. With today's batteries outcome will not be that useful, batteries are too heavy, but there are promising battery technologies coming within a decade or so if they are successful.
I have been thinking about stol plane stol takeoff and landing where the plane stays in the air with the lift augmented by the prop stream. Then I was looking at coanda effect. It is about the same thing as what happens on top surface of a wing and the boundary layer is attempted to be attached to the bending surface. The problems with coanda effect demonstrators seem to be related to detaching boundary layer.
And one boundary layer control method is suction. What it you would combine the propulsion, blowing and suction in circular shaped body:
I was at first thinking about blades outboard of circular body like this blog post:
DESIGN|A|PLANE: Idea: Helicopter with the blades extendeding from the outer edge of a lens shaped lifting body
Then I figured it might not be the optimal solution. What if you would have ring of ducted props around the circular body providing suction to the upper side and bent inwards on underside so it would be effectively blowing on the bottom surface. In other words simulate condition of forward movement of half airfoil without foward movement. The lift would not rely on the propellers like in quadro copters, but instead would take advantage of the lifting body.
Since the props on the outer rim of the aircraft would have small inertia and the response speed of a small brushless electric motor is fast, it would be quite possible to make software stabilization in hover for this kind of vtol aircraft.
To get forwards, there would need to be possibly separate drive motors & fans on upper surface so the circular lifting body could travel at positive angle of attact and would behave like a very low aspect ratio wing on cruise (not ideal airfoil though because leading edge and trailing edge has to be sharp for symmetry). Not the best for cruise efficiency, but at least cruise would not depend on vertical lift from the multiprops. And also the whole idea of this kind of vtol would not be to travel long distances, but instead take off and land where aircraft can't. Ideally lifting off directly from one's frontyard and landing on airport to get to a non-vtol airplane to cross long distances. So even as small as 60 km range would be already quite useful.
If we forget issues of combustion engines and consider an electric vtol. With today's batteries outcome will not be that useful, batteries are too heavy, but there are promising battery technologies coming within a decade or so if they are successful.
I have been thinking about stol plane stol takeoff and landing where the plane stays in the air with the lift augmented by the prop stream. Then I was looking at coanda effect. It is about the same thing as what happens on top surface of a wing and the boundary layer is attempted to be attached to the bending surface. The problems with coanda effect demonstrators seem to be related to detaching boundary layer.
And one boundary layer control method is suction. What it you would combine the propulsion, blowing and suction in circular shaped body:
I was at first thinking about blades outboard of circular body like this blog post:
DESIGN|A|PLANE: Idea: Helicopter with the blades extendeding from the outer edge of a lens shaped lifting body
Then I figured it might not be the optimal solution. What if you would have ring of ducted props around the circular body providing suction to the upper side and bent inwards on underside so it would be effectively blowing on the bottom surface. In other words simulate condition of forward movement of half airfoil without foward movement. The lift would not rely on the propellers like in quadro copters, but instead would take advantage of the lifting body.
Since the props on the outer rim of the aircraft would have small inertia and the response speed of a small brushless electric motor is fast, it would be quite possible to make software stabilization in hover for this kind of vtol aircraft.
To get forwards, there would need to be possibly separate drive motors & fans on upper surface so the circular lifting body could travel at positive angle of attact and would behave like a very low aspect ratio wing on cruise (not ideal airfoil though because leading edge and trailing edge has to be sharp for symmetry). Not the best for cruise efficiency, but at least cruise would not depend on vertical lift from the multiprops. And also the whole idea of this kind of vtol would not be to travel long distances, but instead take off and land where aircraft can't. Ideally lifting off directly from one's frontyard and landing on airport to get to a non-vtol airplane to cross long distances. So even as small as 60 km range would be already quite useful.