This program was created to help streamline the initial design phase when creating a tiltrotor aircraft. This type of a/c helps fill the need for efficient cargo carring drones that can operate without a runway and/or landing strip. This project was completed to help AerospaceNU, the aerospace club of Northeastern University during the Fall 2021 semester. The image below represents an example of what a prototype could look like given the outputs.
I tried to be very complete in creating a useful model to streamline the initial design phase. The model is not without assumptions but (in my opinion) represents a helpful tool in novel a/c design.
Some physical phenomenon that are modeled include:
- Skin friction drag with a boundary layer theory.
- Form drag from airfoil data
- FAA structural loading limits
- Disk loading to estimate hovering power costs
- Taper ratio and induced drag
- Euler bending beam theory for thin structures (torsion and bending)
- Battery considerations for electric flight
Edit this file to your chosen airfoil and a/c dimensions:
inputs.csv
Main fuction that puts everything together:
$ python GenerativeDesign.py
- ReadInputs.py - Specific data to the aircraft like mass, wingspan, coefficient of lift, etc.:
- AeroDrag.py - Skin friction, form, and induced drag calculations:
- Hover.py - Power and energy requirements from hovering flight:
- Structures.py - Euler beam theory and associated equations
- WingCalculations.py - Iterative process to reduce wing mass:
- UAVdesign.py - miscellaneous calculations and tradeoffs:
The plots below give an example of the expected output when you run $ python GenerativeDesign.py
in your terminal. The red dot denotes the ideal starting design to maximize flight duration given the current constraints. Please adjust the inputs.csv file to tailor the program to your needs. The far right image is the expected output on your terminal. Use these dimensions to design the a/c model.
Important things of note are:
- The white area in the upper right corner of each plot is beyond the structural limit and the a/c will fail!
- The rotors always extend past the wing tips. See the above photo for an example model.
- The program assumes all structural load is taken by carbon fiber spars in the wings.
Numerous studies were used to find relevant equations to create a realistic model. Please use the following thinks to access the original papers. Some files may have a paywall that limit access.
- https://www.researchgate.net/figure/XV-15-tiltrotor-aircraft-layout-Ref-9_fig3_23847162
- https://www.sciencedirect.com/science/article/pii/S2352146518300383
- https://books.google.nl/books?id=-PnV2JuLZi4C&pg=PA42&lpg=PA42&dq=power+required+to+hover+watts+per+kg&source=bl&ots=iS07eZFRKr&sig=ACfU3U2BjfLfAVHgaFQWmAX8z5_0TVsmUQ&hl=en&sa=X&ved=2ahUKEwjDx7Pg9ZvyAhWho3EKHU_EAwoQ6AF6BAgeEAM#v=onepage&q=power%20required%20to%20hover%20watts%20per%20kg&f=false
- https://www.epi-eng.com/propeller_technology/selecting_a_propeller.htm
- https://airfoiltools.com/airfoil/details?airfoil=sd7062-il
- https://www.risingup.com/fars/info/part23-337-FAR.shtml