[JoeF]

Captive-Ellipse Hang Gliders

This thread invites a focused discussion on "Captive-Ellipse Hang Gliders."

Note: A circle is a special case of an ellipse, so a CEHG has already been made and flown. This thread aims to explore the possibilities of both circle-ellipse and non-circle-captive-ellipse framed hang gliders. Studies on both TPHG and non-TPHG CEHGs are welcome. TPHGs pack in under 5 feet, while non-TPHGs pack in over 5 feet in length.

Note: While "circle" and "ellipse" are often used in this context, it's important to recognize that they represent a simplified abstraction. The actual 3-D forms involved may include shapes like rings, tori, or segments of cylindrical shells, which are the materials that will primarily be used. However, for ease of discussion, "circle" and "ellipse" remain acceptable terms in this context.

Anyone interested in unfolding the CEHG universe is welcome to post in this thread.

[JoeF]

We join some of the posts that are embedded in another topic thread with this post:
https://ushawks.org/forum/viewtopic.php?f=2&t=1916&p=34120&#p34120
and some of the posts that follow that.

And maybe adopt the same logo found in that initial discussion:


Or go with:

Maybe this image for a first logo for the CEHG exploration????

CEHGlogo001.jpg (10.94 KiB) Viewed 326 times

The small black line in the ellipse indicates kingpost and two queenposts.
===================================================

[JoeF]

Captive-Ellipse Hang Gliders

This topic thread explores a unique design approach to hang gliders, centered on the innovative use of a tensegrity-based structure instead of a traditional keel beam. The following concepts define this special focus:

• No Central Keel Beam: Unlike conventional designs, the stability and structure of these hang gliders are derived entirely from the interplay of tension and compression between the elliptical frame, the taut sail, and the central posting system.
• No bowsprit.
• No conventional crossbar or spreader.
• Tensegrity System as the Core: The kingpost and queenposts act as a floating beam system, stabilized by stay lines radiating to key planetary points on the rigid elliptical frame. This arrangement supports the pilot and provides structural integrity without a solid keel.
• We may explore a simple framed TCF (triangle control frame) that acts as a tensegrity beam and function as a floating upper and lower posting system, so one does not see a conventional king posting.
• Pilot Integration: The pilot hangs directly from this dynamic tensegrity system, experiencing the balance of forces created by the interplay of sail tension and frame rigidity.
• Ribs, baton, stuffers, airfoil curving? A world of exploration may be available here.
• Single sail or double sail Explore both.
• Elliptical Innovation: The fully enclosed elliptical shape—featuring both leading and trailing edges—ensures aerodynamic efficiency. The narrow wing tips define the elongated ellipse and help distribute loads evenly across the sail and frame.

This thread invites creative exploration of circle-ellipse and non-circle-ellipse framed gliders under this concept. TPHG (Tiny Packed Hang Gliders) studies are especially welcome, alongside non-TPHG designs. Enthusiasts, experimenters, and designers are encouraged to share insights, questions, and progress as we collectively unfold the potential of these revolutionary structures.

\
Page might have some helpful notes: https://eaglepubs.erau.edu/introductiontoaerospaceflightvehicles/chapter/wing-shapes-and-nomenclature/
https://www.airfieldmodels.com/information_source/math_and_science_of_model_aircraft/formulas/elliptical_wing_area.htm

[JoeF]

Artists are invited to post renderings of concept in this CEHG world.

**Visualizing the Captive-Ellipse Hang Glider**
This thread invites you to contribute your artistic or technical renderings of the Captive-Ellipse Hang Glider (CEHG). Below are a few ideas for visual representations to inspire collaboration!

======================================

1. Isometric View
Description:
The glider is shown at an angle, capturing its three-dimensionality. The elliptical frame is emphasized as a rigid outer ring, with a taut sail filling the inner area. The kingpost rises centrally, flanked by two queenposts that form a slight "V" or beam-like shape. Stay lines radiate from these posts to the outer ellipse at evenly spaced "planetary points." The pilot is shown hanging directly below the central tensegrity structure, suspended by a harness.

Render Suggestions: A semi-realistic view to give a sense of structure and design.

=========================================

2. Schematic/Exploded Diagram
Description:
A deconstructed view of the glider, with the following components laid out:

• Elliptical Frame: Depicted as a rigid outer loop.
• Sail Fabric: Highlighted as the taut, load-distributing element that connects to the frame.
• Kingpost and Queenposts: Displayed as three vertical members (one central, two flanking) forming a load-sharing system.
• Stay Lines: Shown as radiating thin lines from the kingpost and queenposts to specific points on the elliptical frame.
• Pilot: Positioned in the center, hanging from the tensegrity system.

Render Suggestions: Technical and labeled for clarity, perfect for showing structural interactions.

==========================================

3. Minimal Line Drawing
Description:
A clean, abstract depiction using simple lines and shapes.

• The ellipse is a bold, continuous loop.
• The kingpost and queenposts are drawn as slender lines within the ellipse, slightly inclined for visual balance.
• Stay lines are drawn as thin, angled rays connecting the posts to the ellipse.
• The pilot is represented by a small, simple figure hanging from the midpoint of the kingpost.

Render Suggestions: A minimalist aesthetic, great for quick conceptual sketches.

=================================================

4. Dynamic Flight Scene
Description:
A perspective showing the glider in flight against a neutral or sky-like background.

• The elliptical wing is tilted at a slight angle to convey forward motion.
• The sail is taut, and the stay lines are visibly tensioned.
• The pilot hangs suspended beneath, with wind currents implied by light lines or gradients flowing around the structure.

Render Suggestions: A creative and lively illustration to capture the imagination.

==========================================

We welcome your contributions! Whether you are an artist, engineer, or curious enthusiast, feel free to share your sketches, 3D models, or any other interpretation of the CEHG. If you’re not an artist, your ideas for visual design are equally valuable—describe them here, and we’ll work together to bring them to life!

[JoeF]

TCF as tensile-float beam in CEHG.

TCFasFloatBeam001.jpg (20.75 KiB) Viewed 317 times

A tall TCF acting simultaneously as both the kingpost and queenposts,
while tensionally floating in the tensegrity structure of the CEHG.

ChatGPT nudged wanted to play:

Here’s a creative draft for a caption to enhance engagement and understanding:

TCF as tensile-float beam in CEHG.

TCFasFloatBeam001.jpg (20.75 KiB) Viewed 317 times

The Floating Beam of the CEHG Universe
Behold the Tall Central Framework (TCF, triangle control frame), tensionally suspended in perfect balance! Acting as both the kingpost and queenposts, this innovative structure is anchored to the elliptical frame through a web of taut stay lines. This tensegrity masterpiece forms the heart of the Captive-Ellipse Hang Glider, supporting the pilot in an elegant dance of forces.

Explore, innovate, and share your ideas for this bold reimagination of flight!

My assistant wanted to suggest:
For visual representation, here are some suggestions:

Refined Diagrams:

Use clean, minimalistic vectors to highlight the elliptical frame, TCF, and stay lines.
Color-code components (e.g., frame = black, TCF = blue, stay lines = red).
Add labels or arrows to explain the function of each part.
Dynamic Visualization:

Create a perspective view showing the glider in flight, with the pilot suspended.
Emphasize how forces flow through the tensegrity system.
Inspiration Concepts:

Incorporate abstract wings or feather motifs around the ellipse to symbolize flight.
Use stylized arrows to represent airflow dynamics.

[JoeF]

Some tease:
https://eureka.patsnap.com/patent-CN109969373A
How might a near standard high-aspect ratio elliptical HG frame be approximated with straight CF tubes that nest in two or three or four tube nests with an aim at tiny packing the HG? TPHG? And perhaps use Joe Cup coupling system?
https://opencivilengineeringjournal.com/VOLUME/11/PAGE/131/FULLTEXT/
.
.
.
.

[JoeF]

Two slightly overlapping circular or elliptical rings for a glider begin to show the development of a keel in the glider. Otto Lilienthal approximates such geometry in his Normalsegelapparat; but he did not use the captive arc or captive circle principle; he used radiating ribs to tauten the sail fabric. Discuss all this.

The idea of slightly overlapping circular or elliptical rings as a structural element in a glider design provides a fascinating avenue to explore aerodynamic and mechanical principles. Here's an in-depth discussion of this concept in the context of hang glider development and comparisons with Otto Lilienthal's pioneering designs, specifically his Normalsegelapparat:

---

Concept of Overlapping Rings in Glider Design
1. Overlapping Rings as a Keel Development:
- The slight overlap of two circular or elliptical rings creates a structure with potential to serve as a keel-like element.
- This configuration could distribute loads symmetrically and provide inherent structural stability without the need for a central, linear beam (as is common in conventional designs).
- The overlapping geometry also has the potential to create zones of tautness where fabric sails can be tensioned effectively. These tensioned regions, formed between the arcs of the rings, would create aerodynamic lift surfaces.

2. Captive Arc or Circle Principle:
- The "captive" principle involves using a hard frame (elliptical or circular) that is kept in shape by stay lines and the tension in the sail.
- This eliminates the need for internal ribs or beams radiating outward, reducing structural weight while maintaining aerodynamic efficiency.
- The overlapping rings could provide unique zones where such captive structures could "lock" into a desired shape and provide multiple attachment points for rigging, further enhancing the flexibility of the glider's design.

---

Comparison with Otto Lilienthal's Normalsegelapparat
1. Normalsegelapparat's Radiating Ribs:
- Otto Lilienthal's Normalsegelapparat used a central keel beam and ribs radiating outward to support a fabric sail. These ribs were crucial in shaping the airfoil and providing structural integrity.
- Lilienthal's approach relied heavily on the uniformity of rib spacing to ensure consistent tension in the sail fabric, which directly influenced the aerodynamic performance of his gliders.
- This method was effective but added weight and complexity to the design.

2. How Captive Arc Differs:
- Unlike Lilienthal's radiating ribs, the overlapping rings and captive arc principle focus on tension and compression relationships within the frame and rigging system. This allows the structure to "float" in a tensegrity-like balance without the need for rigid internal ribbing.
- The sail fabric in a captive arc design becomes integral to the structural system, held taut by stay lines connected to key points along the overlapping rings.

3. Aerodynamic Evolution:
- Lilienthal's designs represent an early understanding of aerodynamics and structural integrity, but they were constrained by the materials and engineering knowledge of his time.
- The overlapping rings approach could advance these concepts by enabling lighter, more flexible designs with the potential for modularity and portability (such as in modern TPHG systems).
- The elliptical or circular arcs allow for a more organic integration of aerodynamic principles, potentially creating smoother airflow over the surface and reducing drag compared to ribbed structures.

---

Potential Applications and Challenges
1. Applications:
- Such a design could be used for ultralight gliders, parachutes, or even micro-aerial vehicles where weight and simplicity are critical.
- The dual-ring system might also allow for innovative control systems, where shifting the tension in specific stay lines could alter the wing shape dynamically, providing new methods of flight control.

2. Challenges:
- Achieving the right balance of tension and compression within the rings and stay lines could be complex. Excess tension could deform the rings, while insufficient tension might lead to a collapse of the sail.
- Material selection is crucial—both for the rings (to ensure lightweight rigidity) and the stay lines (to handle the dynamic loads without stretching excessively).

---

Conclusion:
The overlapping ring concept and the captive arc principle offer a modern reinterpretation of Otto Lilienthal’s structural ideas. By reducing reliance on radiating ribs and using stay lines for structural integrity, the design could pave the way for lighter, more efficient gliders. Lilienthal’s pioneering work, particularly with his Normalsegelapparat, remains a cornerstone, but these innovations represent how advancements in materials and design philosophies can transform his foundational ideas into futuristic applications.

NormalPatentDrawing.JPG (40.69 KiB) Viewed 287 times

[JoeF]

Scene: captive ellipse of stubby shape (tensegrity: post and upper and lower staying rigging to prevent collapse of ring). The rigging could keep the form, but a sail or webbing or net in the planer disk could enrich the captive scene. Assume materials and form are set. Then this development not: Relaxingly develop atop-sail low-mass aero-curving system. Explore different such aero-curving systems.

[JoeF]

Hallucination by Artificial Intelligence upon some of my prompt. Not close to my intention.

AI001.JPG (47.99 KiB) Viewed 275 times

Hallucination by Artificial Intelligence upon some of my prompt. Not close to my intention.

AI002.JPG (45.74 KiB) Viewed 275 times

Hallucination by Artificial Intelligence upon some of my prompt. Not close to my intention.

AI003.JPG (44.55 KiB) Viewed 275 times

Hallucination by Artificial Intelligence upon some of my prompt. Not close to my intention.

AI004.JPG (53.61 KiB) Viewed 275 times

Hallucination by Artificial Intelligence upon some of my prompt. Not close to my intention.

AI005.JPG (48.13 KiB) Viewed 275 times

[JoeF]

Captive-disk with additive beams

AnchoringBeamsToCaptiveEllipticalDisk.jpg (40.48 KiB) Viewed 97 times

Whether an aim is TPHG (tiny packed hang glider) or larger short-pack or long pack hang gliders,
using the tautness of captive ellipse might come in handy in forming sails or control surfaces or direct dynamic control.

=====================
Filler: Do you see the hang glider on the book cover?

BookCoverArtIncludesAhangglider.jpeg (29.76 KiB) Viewed 88 times