The primary research objective was to develop a methodology to support conceptual design of the Hybrid Wing Body (HWB) configuration. The absence of a horizontal tail imposes new stability and control requirements on the planform, and therefore requiring greater emphasis on control authority assessment than is typical for conceptual design. This required investigations into three primary areas of research. The first was to develop a method for designing an appropriate amount of redundancy. This was motivated widely varying numbers of trailing edge elevons in the HWB literature, and inadequate explanations for these early design decisions. The method identifies stakeholders, metrics of interest, and synthesizes these metrics using the Breguet range equation for system level comparison of control surface layouts. The second area of research was the development trim analysis methods that could accommodate redundant control surfaces, for which conventional methods performed poorly. A new measure of control authority was developed for vehicles with redundant controls. This is accomplished using concepts from the control allocation literature such as the attainable moment subset and the direct allocation method. The result is a continuous measure of remaining control authority suitable for use during HWB sizing and optimization. The final research area integrated performance and control authority to create a HWB sizing environment, and investigations into how to use it for design space exploration and vehicle optimization complete the methodology. The Monte Carlo Simulation method is used to map the design space, identify good designs for optimization, and to develop design heuristics. Finally, HWB optimization experiments were performed to discover best practices for conceptual design.

The student inclusive Green Raven project of the KTH-Aero faculty requireda small blended wing model of their new flying wing design. The small scalemodel will be used for various flight tests. The goal of this specific project was tocreate an internal structure for the small scale model, including an outer shell.Two-dimensional drawings were created and tested in a simulation software.The model was then drawn in cad. Lastly the wing was strength tested inAnsys mechanical. The beams in the structure are made of Scots pine due toits accessibility and good strength to weight ratio. The outer shell is made outof fiberglass. A quick connection between the wing and the main body wasimplemented for easy transportation. All final testing indicate that the finaldesign had sufficient strength regarding the initial load requirements.

The work summarized in this report aims to investigate how a drone airplane design can be optimized to create a safer and more efficient sea rescue by providing staff with an early picture, performing search missions and aiding communication through visual contact. A flying wing is in theory one of the most efficient designs for a fixed wing aircraft, at the same time as it also offers high structural efficiency for its given size. In this report, an overview of aerodynamics, stability and flying quality for a flying wing is discussed and analysed. XFLR5 was used for this project, and a comparison between the analytical results and wind tunnel test data for a prototype was conducted. A strong correlation was found between the theoretical analyses and the wind tunnel data. A simple control solution using only one set of elevons has been proposed and simulated, resulting in Level 1 dynamic stability for all modes except Dutch-roll (where the drone’s damping is 𝜁𝑑𝑟=0.07 and the requirement for Level 1 is 𝜁𝑑𝑟=0.08). For the range of angle of attack used, the autopilot system will have to trim the drone in flight to achieve stability. As the drone only has one set of control surfaces there will be a loss of efficiency in this scenario, meaning that 𝐶𝐿/𝐶𝐷 = 15.7 for loiter speed of 15 𝑚/𝑠 and 7.9 for full speed at 35 𝑚/𝑠. In regular flight, with a total mass <1 𝑘𝑔, the drone is able to fly at full speed for 214 𝑘𝑚 or loiter for 6.3 ℎ with a battery package of 130 𝑊ℎ. As such, the objective of this project was achieved, and the proposed design met the given requirements. / betet som sammanfattas i denna rapport syftar till att undersöka huruvida ett drönar-flygplan bäst kan utformas för att skapa en säkrare och effektivare sjöräddning genom att ge räddningspersonalen en tidig överblick, utföra sökuppdrag och bistå till kommunikation genom visuell kontakt. En flygande vinge är i teorin en av de mest effektiva konstruktionerna för ett flygplan, likaså erbjuder den en hög strukturell effektivitet för en given storlek. I denna rapport diskuteras och genomförs en översikt över aerodynamik, stabilitet och flygkvalitet hos en flygande vinge. XFLR5 användes för detta projekt, och en jämförelse mellan analysresultaten och ett vindtunneltest med en prototyp genomfördes. I allmänhet är överenskommelsen mellan de teoretiska analyserna och vindtunneldatan god. En enkel lösning som enbart består av en uppsättning kontrollytor har föreslagits och simulerats, vilket resulterar i en Nivå 1 dynamisk stabilitet för alla lägen utom Dutch-roll, där drönarens dämpning är 𝜁𝑑𝑟 = 0.07 och kravet för Nivå 1 är 𝜁𝑑𝑟 = 0.08. Autopilotsystemet behöver trimma drönaren under flygning för att uppnå nödvändig stabilitet för det spann av attackvinklar som används, med endast en uppsättning kontrollytor, vilket minskar effektiviteten för BWB-drönaren till 𝐶𝐿/𝐶𝐷=15.7 för cirkuleringshastigheten på 15 𝑚/𝑠 och 7.9 för full hastighet vid 35 𝑚/𝑠. Drönaren kan flyga i full hastighet i 214 𝑘𝑚 eller cirkulera runt olycksplatsen under 6.3 timmar med ett batteripaket på 130 𝑊ℎ, med en vikt som är lägre än 1 𝑘𝑔. Målen med detta projekt uppnåddes och drönaren utformades enligt kraven.