LSM-SEMINAR

Study of Hyperloop pod equipped with compressor to overcome the Kantrowitz limit

by Mr Maurice Bizzozero

Europe/Zurich
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https://ethz.zoom.us/j/92403590378

Description

Abstract:

The Hyperloop concept is an innovative mode of transportation in which capsules travel at high speed in nearly evacuated tunnels which minimize the aerodynamic drag. The so-called Kantrowitz limit defines the conditions at which the flow chokes when squeezed in the bypass of a travelling pod. This occurs when the pod travels too fast or when its relative size with respect to the tube is too big. When the Kantrowitz limit is overcome, the pressure accumulates in front of the pod, which is then forced to push the whole column of air ahead. This can significantly increase the drag and compromise the performance of the pod. An axial compressor mounted in the fore part of the pod is proposed in the original formulation by Elon Musk with the purpose of releasing part of the pressure by allowing more throughput. This thesis investigates the possible benefits of mounting a compressor to mitigate the Kantrowitz limit.

Two simplified approaches are implemented in 2D, axisymmetric CFD simulations in order to represent a compressor. Several blockage ratios and pod Mach numbers are tested for different compressor pressure ratios. The simulation results show that above the Kantrowitz limit it is almost always beneficial to equip a compressor. The highest gains are observed for conditions further above the Kantrowitz limit, namely for high blockage ratios and high pod speeds. Up to 47 % of power consumption can be saved.

Organised by

Laboratory for Scientific Computing and Modelling

Dr. Yohei Sato