Department of aeronautics - Imperial College London
Generative Structural design of a novel synchropter for the aerial recovery of falling rocket stages
Abstract
There is an increasing demand for resuable rockets in the industry. A recoverable rocket would reduce costs and a need for raw material, saving the Earth its natural resources. In this project, an aerial vehicle was designed to recover falling spacecraft stages. Aerial vehicles such as an Aircraft, Vertical Take-Off Landing (VTOL) and Helicopters were explored. After an analysis of the mission profile and other requirements, the helicopter was chosen. The baseline configuration process resulted in the helicopter having an intermeshing rotor design (synchropter) with an H-tail and landing skids. The helicopter was designed to be unamanned due to the safety requirements of the mission. After the systems layout was decided, an airframe was designed around these components. It was decided to a have a truss structure instead of a traditional monocoque/ semi-monoocoque design. Due to this, technologies such as Topological Optimisation and Generative Design were used to come up with a more innovative process and design.
The final design was a truss strucutre weighing only 120 kg, with an expected mass of 130 kg after assembly. Scroll down to see the rough process of how this approach was taken.
Please email if you’d like a copy of the report that goes through a more detailed process and results section. This project was a part of Imperial College London - Department Of Aeronautics - YEAR 3 - Group Design Project (GDP) .
Airframe designed by Atri Sharma and Tejasva Malhotra, academic year 2019 - 2020.
The process
Setup
The setup for a Generative Design study requires creating preserve and obstacle regions. The preserve regions (parts in green) tell the software to PRESERVE these regions as they are needed for the assembly. The obstacles (parts in red) tell the software to not let any material enter this area. After applying loads, constraints, materials, and manufacturing techniques, a design criteria must be set.
Iterate
After the setup, a setup is submitted to the cloud for simulation purposes. After some hours, outcomes are generated, the number depending on how many materials and constraints were added. The “Converged” outcomes are the ones that successfully converged to a solution. However, most of the time these outcomes are difficult to manufature and must be simplified.
Simplify
Once an outcome has been selected, it can be used as a reference to identify major load paths. Standard CAD techniques such as extrude, revolve, sweep and loft can then be used to come up with a simplified structure, in this case a truss structure for ease of manufacturability, and compact design. A standard simulation must be ran to ensure that the design is safe and meets all the loading constraints.