Introduction to Fixed-Wing Drone Design

Access the general sizing spreadsheet via the udemy link, sign in if needed, make a copy in google docs, save it to google drive, and edit.

Learn to use the general sizing spreadsheet to size a fixed-wing drone, estimating endurance, range, stall, wing loading, payload, batteries, propulsion, and performance plots.

Access two web-based aerodynamics tools—mockup four (non-dimensional, Fortran backend) and mockup five (dimensional, Python backend with propeller aerodynamics)—with configurable units.

design a compact fixed-wing drone for search and rescue, backpack portable and hand launched, meeting a 30 km range, 7 m/s stall margin, and 150 g payload.

Evaluate payload of 0.15 kg, target a 35% mass fraction for a foam airframe, and adjust airframe weight as battery weight and avionics power change, iterating on drag and density.

size the main wing by adjusting wing loading and aspect ratio to optimize efficiency, estimate max lift as 0.8 times the airfoil, and show how loading shifts stall speeds.

Increase propulsion capacity with a lithium polymer battery to meet range goals, adjust mass fraction, airspeed, and wing loading to optimize stall margin and overall aircraft range.

Balance mass fraction, airspeed, and stall margin to extend range while meeting packing constraints for a fixed-wing drone with a 90 cm semi span split into two halves.

Size horizontal and vertical stabilizers using tail volume ratios, with horizontal around 0.4 and vertical around 0.03, set moment arm semi span, and choose aspect ratio eight with 0.7 taper.

Selects a 3s 7000 milliamp hours lipo battery, reviews weight from product specs, updates estimates in a spreadsheet, and shows how battery weight improves mass fraction and extends range.

Increasing wing loading raises stall speed and minimum airspeed, requiring faster takeoffs and landings, while max flight time decreases and max range remains relatively constant.

Explore how aspect ratio affects range and flight time for fixed-wing drones, showing that higher aspect ratios improve efficiency, while construction limits maximum feasible ratio.

Focus on how reducing weight improves range and flight time for fixed-wing drones, showing a strong initial gain and the relationship between weight, max range, and cruise speed.

Increasing battery capacity raises aircraft weight, yielding diminishing returns on range and flight time while wing area stays constant, and higher weight also raises stall speed, complicating takeoffs.

Explore how increasing propulsive efficiency improves range and flight time in fixed-wing drones, with practical examples showing gains from 40% toward 67–73% theoretical maximum.

Estimate stall speed using the 2D airfoil CL max, multiplied by 0.8. Compare how CL max shifts minimum airspeed via the minimum-velocity equation, considering wing loading and air density.

Refine a mission-specific fixed-wing UAV by mocking up the wing and stabilizers, choosing Clark Y and NACA four-digit airfoils, and applying rules of thumb for t-tail, sweep, washout, and dihedral.

The lecture demonstrates adding control surfaces to the horizontal and vertical stabilizers, configuring elevator and rudder deflections, excluding ailerons, and using dihedral to provide roll stability.

Model a fuselage with a simplified representation to visualize sizes, noting mockups don’t affect drag calculations. Elongate a sphere along the x-axis by six and color components for distinction.

Add a battery box with dimensions 140 by 41 by 35 mm (0.140 by 0.041 by 0.035 m), color it differently, and place it in the fuselage nose for visualization.

Export your fixed-wing drone model as an STL file, name it, and download it to open in other software.

Import non aerodynamic objects into the mock up, like a scaled battery, using a wireframe wing and STL files from Thingiverse to check fit; they aren’t in the aerodynamic analysis.

Explore airfoils in MachUp by configuring root and tip four digit NACA airfoils for mockups, while updating Clark Y data in X foil to drive accurate aerodynamic simulations.

Learn to use Xfoil for airfoil analysis by loading Clark Y data, adjusting paneling, and obtaining lift, drag, and moment coefficients across angles of attack.

Apply basic aircraft forces and moments to trim and stability, using thrust, drag, lift, weight, CG, and the right-hand rule for rolling, pitching, and yawing moments L, M, N.

Learn how aircraft achieve trim by balancing thrust with drag, weight with lift, and zero side forces and moments about the x, y, and z axes.

Explore the two aerodynamic angles defining the incoming velocity for aircraft: angle of attack, alpha, and sideslip angle, beta, using V infinity to understand aircraft control and stability.

explains stability concepts—from stable to unstable—using a ball-in-a-bowl analogy, and states stability requires negative rolling moment with beta, negative pitching moment with alpha, and positive yawing moment with beta.

Learn how fixed-wing aircraft designers non-dimensionalize lift, drag, and moments, define coefficients like cl, cd, cm, cn, and assess pitch, roll, and yaw stability derivatives.

Calculate the static margin as negative CM alpha over CL alpha to assess pitch stability, aiming around 0.05, and keep CG ahead of the aerodynamic center.

analyze forces and moments about the center of gravity for a symmetric aircraft at zero angle of attack, applying the right-hand rule to identify rolling, pitching, and yawing moments.

Explore detailed wing design by analyzing washout, taper, mounting angle, and dihedral, and optimize for a cruise lift coefficient of 0.37 with minimal drag and reference wing area consistency.

Explore how twist, taper, and washout affect lift and drag in fixed-wing drone design, using a lift coefficient of 0.37 and minimizing drag with two degrees of washout.

Set the main wing mounting angle to achieve lift coefficient 0.37 and angle of attack around 1.46 degrees, keeping the fuselage horizontal in cruise to minimize drag.

Explore aerodynamic design and flight mechanics, and understand why propulsion sizing isn't detailed in this course, while using tools to match propeller, motor, ESC, and battery for drone cruise optimization.