Modeling The Hyperloop With COMSOL Multiphysics® : On The Design Of The EPFLoop Pressurized Systems

The EPFLoop team from Ecole Polytechnique Fédérale de Lausanne has developed a capsule thanks to which it won the 3rd place in SpaceX's Hyperloop Pod Competition in 2018. COMSOL Multiphysics was used to analyze and study the pressurized systems of the pod. Three pressure vessels (PVs) of different shape and structure are used to store electrical components in a pressurized environment at 1 bar, meanwhile the external environment is at 8 mbar. The PVs' failure under load was studied using a stationary simulation and shell finite elements in order to represent the plies of carbon fiber-epoxy and foam. The load conditions were the maximum deceleration (2.6 g), the weight of the internal components and the internal pressure of 1 bar. The aim was to design the plies layering with a minimum Tsai-Wu safety factor of 2 everywhere. A parametric sweep was then performed to estimate the maximum allowable working pressure (MAWP, corresponding to a safety factor equal to 2) and the BURST pressure (pressure for which the safety factor is less equal than 1 and failure is imminent). To ensure the normal functioning of electronic components, analyses were done to ensure that the temperature inside the PVs wouldn't be greater than 50°C due to internal electronic heat loads. This has been done by coupling the Heat Transfer in Solid Module with the Laminar Flow Module in order to take into account convection effects. The simulations were validated by measurements during experimental tests. Experimental results confirmed the design and analyses carried out using COMSOL Multiphysics®.