Old ideas being revisited: design nr. 4

Let's now have a look at something completely different:

 Call it as you want: joined wing or box wing is probably the most appropriate definition. I would suggest "canard" joined wing design.
As usual, the idea is to make a foot launchable sailplane, easy to transport, light weight and with a reasonable performance level.
The fuselage is reduced again to the minimum, just streamlining the pilot, with an opening on the belly for foot launching it. Lateral stability should be provided by the vertical surfaces joining the fron and back wings at the tips.

 The elevator is on the front wing and the ailerons on the rear wing. The idea was to keep the wingspan below 10 meters. That was probably too optimistic, since it is giving a very small wing surface. One solution could be to increase the wing chord...

The front view is sexy, isn't it?

Old ideas being revisited: design nr. 3

Today i would like to share another "conventional" solution:

When i sketched that sailplane, the main idea was to design something similar to the Genesis concept.
What does it mean?
Well, i wanted to reduce parassite drag to the minimum by designing a very short fuselage. The wing is equipped with a low pitching moment profile, and that allows to use a short lever arm for the stabilizer. Fuselage length is below 4 meters, making the glider easily transportable. The fuselage has an open floor to allow foot launching. At first i thought about an open cockpit, but also a closed canopy should be feasible. For safety reasons, the sailplane is equipped with a ballistic parachute positioned on the back of the pilot and connected to the main wing spar.
As usual, comments are more than welcome!

Old ideas being revisited: design nr. 2

Let's have a look into a more conventional solution.
The dream is always the same: being able to foot-launch from a hill with the highest possible gliding performance. In other words, that means reducing drag to the minimum, and in order to do so, wetted area must be reduced to the minimum in order to reduce parassite drag. Profile and induced drag are to be minimised by working on the right wing section selection and wing platform configuration. In that specific case, since the architecture is close to a traditional one, wing platform should be optimised in order to get closer to an elliptic lift distribution.
In the next pictures, i've sketched some design variation of the same basic concept:

Picture 1: v-tail

All those design variations are probably too aggressive in terms of wing area. I'm quite sure that a bigger wing surface is required to reduce stall speed to a reasonable value. In comparison with a tailless design there is one advantage: the CLmax of a traditional design can be significantly higher respect to an equivalent tailless design. Should also be easier to implement a flap system that can maximise CL during take off and landing. The fuselage pod has been pushed to the minimum wetted surface: probably needs to be enlarged a bit. An amazing concept is represented by the pilot prone position, giving an outstanding visibility. The biggest drawback is that no-one will feel comfortable having is nose being the first part crashing in case of ground impact...

Picture 2: v-tail

The second picture is more or less showing the same concept.

Picture 3: traditional tail configuration

Third picture shows a bit more traditional configuration for the tail. One of the potential design issues is connected with the short tail harm. This can be achievable only using low Cm wing sections and a big tail area. Unfortunately a low Cm sections usually is also having a low CL max....
A solution could be to increase tail authority by designing a quite extended vertical fin.
Comments are more than welcome!

Old ideas being revisited: design nr. 1

Let me share with all of you some old designs i was drafting some years ago when i was still at the University. Even if most of the courses were exiting (at the end it was aerospace engineering :-) ), some of them were quite boring, and so i was spending my time drafting my dreams.
The one attached below was again related to a foot launch-able tailless glider. In that case, i considered the option to reduce wingspan, wing surface and weight to the real minimum. The design was drafted around a pilot lying in a prone position.

One of the issues to be solved were connected with the wing spar positioning relative to the pilot. The idea was to shape the spar in a way that it was surrounding the pilot body (see the small section view). Sincerely i do not know how feasible it is, but for sure is a potential solution.
From a structural and transport perspective, the idea was to split the glider into 5 parts:

• fuselage pod
• 2 half wings
• 2 winglets

Wingspan was supposed to be 11 m. Considering a 1 meter wide fuselage pod, it means max 5 meters per each wing half, that makes the glider easily transportable on the top of a mid size car.

Intriguing, right?

I hope i'm able to find the time to post all the other designs i was drafting, and would be nice to open a discussion on them. I really want to move forward in building at least a radio controlled model of the concept we will judge as the best one.

Stay tuned, and have good flights!