This tool helps visually explore how changes to wing geometry and basic aircraft parameters affect the front profile and conceptual aerodynamic indices. The visual indicators show the percentage difference or relative change towards an optimum for "Total Drag," "Roll Stability," "Adverse Yaw," "Thermal Turn Stability," and "Air Penetration" relative to a baseline configuration. It's designed for educational and comparative understanding.

The Optimize Joiners assistant suggests joiner angles for the Experimental Wing. It is configured to optimize for an F5J / Light Wind Thermal Specialist aircraft profile, assuming Minimal/Automatic Rudder Usage. The assistant uses the other parameters of the Experimental Wing (weight, wingspan, etc.) as a starting point and considers your selected optimization priority (Penetration vs. Thermal Stability). The suggested angles will remain within the allowable ranges of the input sliders. You can select whether to optimize the Tip Angle, Center Angle, or Both.

Major Assumptions & Simplifications:

• Simplified Indices & Relative Comparisons: The "Roll Stability," "Adverse Yaw," "Thermal Turn Stability," and "Air Penetration" indices are highly abstract. "Total Drag" is calculated based on simplified aerodynamics. The displayed percentages indicate relative change, not absolute performance values.
• Polyhedral Model: The wing is modeled as either a two-panel polyhedral (center + tip panel) or a three-panel polyhedral if the "molded wingtip" option is used. All panel sections are assumed to be straight lines for calculation and drawing.
• Wing Area Estimation: Wing area is estimated for a tapered wing using the root chord, wingspan, and an assumed taper ratio of 0.45 (TipChord = RootChord * 0.45).
• Reference Airspeed: Lift coefficient is calculated assuming a fixed reference airspeed (configurable per profile, default 12.0 m/s) to maintain Lift = Weight. Drag is then calculated at this speed.
• Parasite Drag: Influenced by geometric factors in an illustrative way, modifying a base parasite drag coefficient of 0.02.
• Oswald Efficiency (e): Assumed constant at 0.8.
• Aileron Authority Index: Conceptually models the directness and responsiveness of roll control. It is primarily influenced by the aileron's length and its position on the wing, as ailerons placed further out have more leverage and are more effective. The model also accounts for how the wing's overall dihedral creates a self-leveling tendency (roll stability), which the ailerons must overcome. It does not account for aileron chord, deflection throws, servo speed, or wing structural flex.
• Adverse Yaw Index: Conceptually influenced by wingspan and effective dihedral. More dihedral helps counteract adverse yaw. The model does not simulate ailerons or true yawing moments. The Optimization Assistant assumes minimal rudder input is preferred for the F5J profile.
• Thermal Turn Stability Index: Conceptually aims for an optimal balance of dihedral and other factors for ease of maintaining a bank in thermals (F5J profile). Not a direct measure of spiral stability in the classical engineering sense. An optimal index value is targeted, specific to F5J-style flight.
• Air Penetration Index: Conceptually represents the ability to fly efficiently against the wind, influenced by wing loading and total drag coefficient at the reference airspeed.
• Chord-to-Span Ratio Warning: The root chord input field will highlight if the ratio of root chord to wingspan becomes unconventionally shallow (<0.03) or deep (>0.18).
• No Airfoil/Planform Detail: Does not include specific airfoil data, Reynolds/Mach effects beyond the simplified parasite drag, detailed top-view planform geometry (beyond the assumed taper), or wing twist.
• Static Geometry: Models the un-deflected wing shape; control surface deflections are not considered.
• No Structural/Full Stability Analysis: Ignores structural integrity, detailed longitudinal/directional stability beyond the conceptual roll stability index.

Disclaimers:

• Not for Direct Engineering or Flight-Critical Decisions: The simplified outputs are not suitable for making final engineering decisions for building, modifying, or flying any aircraft.
• Illustrative Only: Visuals and percentage differences are conceptual and relative.
• No Guarantee of Quantitative Accuracy: Percentage differences do not reflect precise, actual aerodynamic performance figures.
• Consult Experts: For any aircraft design or modification, always consult qualified professionals.

This software is provided "as is", without warranty of any kind, express or implied, including but not to the warranties of merchantability, fitness for a particular purpose and noninfringement. In no event shall the authors or copyright holders be liable for any claim, damages or other liability, whether in an action of contract, tort or otherwise, arising from, out of or in connection with the software or the use or other dealings in the software.

This tool is for educational and illustrative purposes only.