Simulation of a Proprotor Hub for Sora Aviation 

Sora Aviation, a UK-based start-up, is developing a 30-seat eVTOL (electric vertical take-off and landing) aircraft, the S-1, for the AAM (advanced air mobility) market. Designed for zero emissions, low noise, and affordability, the S-1 provides a sustainable and scalable solution for congested urban environments. With a focus on safety and efficiency, Sora Aviation aims to transform urban transportation, particularly for high-demand routes such as airport shuttles. 

Detailed design of a zero emissions aviation solution

As the detailed design of the S-1 continues to evolve using the 3DEXPERIENCE platform and CATIA, critical engineering decisions must be made to achieve overall performance objectives. One key focus area is the design of the proprotor hubs for the aircraft. A diverse range of hub design concepts exists for various aircraft propeller and rotor systems, with the optimal choice depending on factors such as proprotor blade design and retention methods, pitch control mechanism configuration, and the load variations between vertical and forward flight. Given the impact of these critical design decisions on the mass, reliability, and performance of the proprotor systems, it was essential for Sora Aviation to develop an efficient method for rapidly evaluating various concepts under representative loading conditions. This approach enabled the team to focus on the most promising options for further development.  

Challenges of designing a proprotor hub

Designing the proprotor hub for the S-1 posed notable challenges, namely: 

• The hub must accommodate varying aerodynamic and inertial loads from the proprotor blades, which vary significantly between vertical and forward flight.  
• The geometry and material properties must align with the aircraft’s overall weight and performance targets, whilst maintaining reliability and durability across the entire flight envelope.  

Integrating simulation and design within a common system

Sora Aviation required a simulation process that could rapidly assess multiple hub designs under realistic loading conditions, ensuring that the final solution met rigorous safety and efficiency requirements. The process also needed to integrate seamlessly with the CATIA CAD models, enabling seamless updates as the design evolved. 

To meet these challenges, Sora Aviation partnered with TECHNIA to develop a streamlined simulation workflow on the 3DEXPERIENCE platform. This workflow translated CFD-derived aerodynamic loads and proprotor inertial properties into equivalent forces and moments at the blade-hub connection points, enabling precise structural analysis of the hub. The integration with CATIA ensured that the simulation models were automatically updated as the hub’s geometry changed, significantly reducing manual effort and accelerating the design process. 

The collaborative nature of the 3DEXPERIENCE Platform also allowed secure contributions from external experts, ensuring the workflow was robust and dependable before deployment. 

Delivering a streamlined simulation process for design evaluation

The project delivered a streamlined simulation process for proprotor hub design evaluation, fully integrated within the 3DEXPERIENCE Platform. This deliverable relied on our ability to understand the multidisciplinary engineering problem, develop an integrated simulation process with minimal complexity, and seamlessly implement it within the customer’s data environment.