High aerodynamic efficiency is a key design driver for airborne wind energy systems as it strongly affects the achievable energy output. Conventional fixed-wing systems generally use aerofoils with a high thickness-to-chord ratio to achieve high efficiency and wing loading. The box wing concept suits thinner aerofoils as the load distribution can be changed with a lower wing span and structural reinforcements between the upper and lower wings. This paper presents an open-source toolchain for reliable aerodynamic simulations of parameterized box wing configurations, automating the design, meshing, and simulation setup processes. The aerodynamic tools include the steady 3D panel method solver APAME and the CFD-solver OpenFOAM, which use a steady Reynolds-Averaged Navier–Stokes approach with k-ω SST turbulence model. The finite-volume mesh for the CFD-solver is generated automatically with Pointwise using eight physical design parameters, five aerofoil profiles and mesh refinement specifications. The panel method provided accurate and fast results in the linear lift region. For higher angles of attack, CFD simulations with high- to medium-quality meshes were required to obtain good agreement with measured lift and drag coefficients.
The CFD simulations showed that the upper wing stall lagged behind the lower wing, increasing the stall angle of attack compared to conventional fixed-wing kites. In addition, the wing tip boundary layer separation was delayed compared to the wing root for the straight rectangular box wing. Choosing the design point and operational envelope wisely can enhance the aerodynamic performance of airborne wind energy kites, which are generally operated at a large angle of attack to maximise the wing loading and tether force, and through that, the power output of the system.
Strictly Necessary Cookie should be enabled at all times so that we can save your preferences for cookie settings.
If you disable this cookie, we will not be able to save your preferences. This means that every time you visit this website you will need to enable or disable cookies again.
These cookies allow us to count visits and traffic sources so we can measure and improve the performance of our site. They help us to know which pages are the most and least popular and see how visitors move around the site. All information these cookies collect is aggregated and therefore anonymous. If you do not allow these cookies we will not know when you have visited our site, and will not be able to monitor its performance.
Please enable Strictly Necessary Cookies first so that we can save your preferences.
What are cookies? Cookies are small pieces of text sent by your web browser through a website you visit. A cookie file is stored in your web browser and allows the service or a third party to recognise you and make your next visit easier and the service more useful to you. Cookies can be “persistent” or “session-dependant” cookies.
When you use and access Kitepower’s online resources, we may place a number of cookies files in your web browser. Cookies can be used for the following purposes:
to enable certain service-related functions
to provide analytics
to store your preferences
to enable advertisements delivery including behavioural advertising
Kitepower uses both session-dependant and persistent cookies throughout Kitepower’s online services and these may consequently also differ in type: Essential cookies & Third-party cookies. We may use essential cookies to authenticate users and prevent fraudulent use of user accounts. In addition to our own cookies, we may also use various third-parties’ cookies to report usage statistics of our online resources and services as well as deliver advertisements on and through the service. This process does not collect the personal information you provide us with when filling out a form on our website but rather focuses on the anonymous behavioural patterns of visitors interacting with the website itself.