Wing Redesign

Table of Contents

Task Description

This task involves some research into methods of manufacturing and design for that specific type of manufacturing. We intend to keep the general shape of the airfoil from Eclipse V1 to V2. Airfoil information for Eclipse V1 can be found here: https://uwarg-docs.atlassian.net/wiki/x/oYJjm. Majority of the constraints from this doc carry over to the new wing. The goal for this new wing is to have it better scaled for the aircraft based on learnings from the attempted maiden flight. We want to get away from using monokote and balsa wood to fabricate the wing and switch to a composite based airfoil. This is part of the research task to find a suitable manufacturing method.

Previous wing was a NACA 6412

Check out NACA airfoil generator to generate plots of different airfoil shapes: NACA 4 digit airfoil generator (NACA 2412 AIRFOIL) (airfoiltools.com)

Other resources:

How To Read NACA airfoils (4 digit, 5 digit, 6 digit) (youtube.com)

Constraints

Assignees

Key Terms

@Nathaniel Li put this here for clarity.

• Chord: imaginary straight line joining the leading edge (usually left) and trailing edge (usually right) of airfoil

• LE: leading edge

• TE: trailing edge

• CL: lift coefficient, determined from type of airfoil and angle of attack

• CD: drag coefficient

• AoA: angle of attack, angle at which chord meets relative wind

• CM: pitching moment coefficient

  • Clockwise (pitch up) positive, counterclockwise (pitch down) negative

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Airfoil Diagram

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AoA Diagram

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Pitching Moment at Aerodynamic Center

Reference Information

Summary of How To Read NACA airfoils (4 digit, 5 digit, 6 digit)

4 digit - Ex. NACA 2412

• First digit 2: max camber of airfoil

  • 2% of chord (or 0.02c)

• Second digit 4: location of max camber

  • 40% of chord (or 0.4c)

• Third and fourth digit 12: thickness of chord

  • 12% of chord (or 0.12c)

• Chord is straight line from leading edge (LE) to trailing edge (TE) going from left to right

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  Ex. NACA 2412

  • In this case 0.4c is the location of max camber

  • t = 0.12c is the thickness

5 digit - Ex. NACA 46015

• First digit 4: design lift coefficient (CL)

  • Multiply by 3/2 and divide by 10 to get CL

  • Ex. 4 x 3/2 = 6 → 6 / 10 = 0.6 → CL = 0.6

• Second and third digit 60: location of max camber

  • Multiply by 1/2 and divide by 10

  • Ex. 60 / 2 = 30 → 30 / 10 = 0.3 → 30% of chord from LE (or 0.3c)

• Fourth and fifth digit 15: thickness in %

  • Ex. 15% of chord length (or 0.15c)

6 series - Ex. NACA 64-320

• First digit 6: series #

• Second digit 4: location of min pressure

  • 40% of chord (or 0.4c from LE)

  • When airfoil is at zero lift condition

• Third digit 3: CL

  • No factor multiplication → CL = 0.3

• Fourth and fifth digit 20: thickness in %

  • 20% of chord length (or 0.2c)Author: @Nathaniel Li Updating Date: Jun 11, 2024

Research of Various NACA Airfoils

• Other NACA airfoils include: 16-series, 7-series, 8-series

• Quick summary based upon course content from Stanfords AA200 Applied Aerodynamics course

  • AA200 Applied Aerodynamics course content

  • NACA airfoil series pdf

Based on the research so far any of the NACA 4 digit airfoil that meets the requirement below will be a good starting point for us to investigate further.

• Camber % 4 to 6

• chord from 9" to 12"

• thickness % 10 to 14

Manufacturing Methods

Research to be done but here are a few methods to take a look at:

• Vacuum Bagging – Composite fabric is laid over a foam or mold core, then vacuum bagged to tightly compress the wing skin for a strong, lightweight structure.

• Resin Infusion – A dry wing layup (over foam or mold) is sealed and infused with resin via vacuum, creating uniform, high-strength wings with minimal weight.

• Wet Layup – Carbon or fiberglass is manually wetted with resin and applied over a foam wing core or mold; accessible but less precise.

• Prepreg Layup – Pre-impregnated composite sheets are laid into wing molds and oven-cured for precision, stiffness, and low weight.

• Foam Core Sandwiching – A shaped foam wing core is wrapped in carbon or fiberglass skins and cured (often under vacuum) for stiffness and structural integrity.

• Bladder Molding – Used for hollow wings with internal structures; a bladder expands inside the composite layup in a mold, pressing it into shape during cure.

• Hot Wire Cutting + Skinning – Foam wings are cut to airfoil shape with a hot wire, then skinned in fiberglass or carbon cloth for a fast and light DIY wing solution.

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Example wing with CF tubes for leading edge

Author: @Christopher Arzoumanian Updating Date: Jul 15, 2025

Airfoil Shape:

4-Digit:

These shapes are generally easier to build and more forgiving, so I recommend starting with trying to build one of these. That being said, 5-digit seems to be better for our applications.

I’ve experimented a bit and optimized for a 4-digit NACA airfoil: NACA 3412

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Max camber = 3%: I believe that the previous design had too much max camber. This design has less lift on takeoff, but really allows the plane to reach its target 25 m/s by reducing drag.

Camber position = 40%: This was a good design choice from the previous airfoil, as it allows for good control of the RC plane.

Thickness = 12-15%: This may change depending on how well the wing can support itself. We can start at 12% and go up to 15% as needed.

5-Digit:

These types of airfoils are mostly what I’ve seen online, especially for RC planes. Building one of these, though more complicated, would definitely help us long-term. Supposedly works well with composite materials. Also, for a hefty plane like ours, I think that better lift at lower speeds would benefit us (plus they have good steering). Seems like the overall favorite from my research.

I’ve been playing around with some airfoil shapes for this, but haven’t found one I really like yet. Maybe a task for next week.

6-Digit and above:

These seem to be quite complicated to build, and therefore out of scope for this project (unless we have hours to spare for construction). Even so, optimizations would be minimal.

Manufacturing Methods

Foam + Carbon Fiber Sheet Vacuum Bagging:

Foam:

Out of all of the manufacturing methods I’ve researched, I believe that foam is a good option because it’s not only lightweight, but is far easier to work with than others material. Balsa/Carbon fiber spars are recommended for structural support (if necessary).

Carbon Fiber Sheet:

Instead of using monokote, a carbon fiber sheet could be used. It’s basically better in every way: (strength, stiffness, structural integrity). Vacuum bagging could save a lot of trouble and would be relatively simple given the correct setup.

A combination of these could be really strong and lightweight:

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Author: @Valerie Gieb Updating Date: Jul 21, 2025

Hot Wire Cutting + Skinning

Hot Wire Cutting:

Hot wire cutting for foam wings seems like a popular choice. The video below provides some helpful tips:

https://www.youtube.com/watch?v=B3hlFm1vCRc

• Templates are attached on either side of the foam (can be laser-cut) to provide a guide for the hot wire cutter

• There needs to be a fair amount of weight on top of the foam while cutting in order to keep it in place → maybe some sort of clamp would be useful?

• If we are putting a spar through the wing for support, the video shows a nice technique for cutting the hole in the foam for the spar:

  • The template has a thin notch where the wire can pass through to get inside the circle cut-out

Skinning:

https://www.youtube.com/watch?v=X6cJCS80BEI

There is an interesting series of videos liked above where someone cuts a wing using a hot wire cutter and covers it in 0.75 oz fiberglass. The main takeaways from this technique are:

1. Thin carbon fiber tow strips were layered on small strips of fiberglass to cover the leading edge of the wing (sort of like a bandage)

2. Two pieces of 0.75 mm polypropylene (mylar) were cut to match the shape of the wing and prepped these with mold release wax. Then, fiberglass pieces were placed on top of the mylar pieces and coated with resin using a roller. Prepreg carbon fiber strips were laid on top of the fiberglass as spars.

3. The foam wing was sandwiched between the two mylar pieces (and fiberglass) and went through the vacuum bagging process (more on this technique in the video)

4. Once the fiberglass was set, the mylar panels were removed to reveal a glossy wing with foam core

Author: @Christopher Arzoumanian Updating Date: Jul 22, 2025

If we want to go with 5-digit airfoil: 23012

Research leads me to believe that airfoil 23012 is good for our application. Thickness (last two digits) can be changed but I believe that the rest would work great for us. This airfoil does very well with composite materials, has a good lift-drag ratio, and is generally used and well liked with RC planes in general.

I found this NASA article kinda glazing it here: https://ntrs.nasa.gov/citations/19930091603

Definitely an option if we decide to go with 5 digit NACA.

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