Abstract—The design of VTOL aircraft, particularly eVTOL aircraft, often relies on the use of multiple electrically powered thrust-vectoring propellers to meet the high thrust requirements of vertical flight. Many configurations employ aft- mounted propellers fixed in a vertical orientation, dedicated exclusively to providing extra lift during vertical take-off and landing. These propellers, left unpowered at cruise, experience crossflow—air moving parallel to the plane of rotation—which in turn induces autorotation. Modeling the aerodynamic behavior resulting from this crossflow-induced autorotation requires a modified mathematical framework—an adaptation of blade element theory—formulated specifically for crossflow conditions. This report presents the formulation of such a model and introduces software developed to solve it numerically, which, given propeller geometry and initial crossflow conditions, computes both transient and steady-state solutions for the propeller’s kinematic and aerodynamic states. These solutions inform the design and optimization of propeller systems for VTOL and eVTOL aircraft by providing insight into design parameters that drive both desired and undesired aerodynamic behavior. Notably, they reveal a strong positive correlation between blade pitch and cruise drag, suggesting that variable- pitch propellers, by leveling the blades at cruise, may offer advantages in improving aerodynamic efficiency.
- @RyanKingSoftware (Desktop Software Developer)
The following platforms are officially supported and have been tested. While the code may compile and run on other systems, only the platforms below are verified:
- Windows x64
- Windows x32
- Linux (Debian) x64
- Linux (Debian) x32
The following tools are required to clone, configure, build, and install the project on Windows:
- Git: Required to clone the repository.
- CMake: Used for configuring the build system, installation, and packaging.
- MSVC: Recommended for compiling the project on Windows.
Use the following command to install all dependencies required to clone, configure, build, install, and package the project on Debian-based Linux systems:
sudo apt install git cmake g++ gcc \
libx11-dev libxrandr-dev libxinerama-dev libxcursor-dev libxi-dev \
libgl1-mesa-dev libglu1-mesa-dev \
libglfw3-dev libglew-dev \
libpng-dev libjpeg-dev \
build-essentialThis project uses Git submodules for dependency management. If you'd like to use the provided versions of all libraries, clone the repository recursively:
git clone --recurse-submodules https://github.com/RyanKingSoftware/propeller-crossflow-autorotation-solver.gitWe recommend creating a build directory within the project folder and using CMake to configure and build the project. This will generate a bin folder containing the compiled executable.
cd propeller-crossflow-autorotation-solver
mkdir build
cd build
cmake -DCMAKE_BUILD_TYPE=Release ..
cmake --build . --config ReleaseTo install the built application, use the following CMake command:
cmake --install . --config Release