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Japan Aerospace Exploration Agency

Using magnetic suspension to illuminate the structures of wake flows in aerospace plane configurations

A magnetic suspension wind tunnel supports a model inside wind tunnel with magnetic force, allowing users to avoid the interference that the supporting devices in conventional wind tunnel testing cause. Therefore, magnetic suspension makes it possible to measure drag coefficients and wake flows for models of various configurations under ideal conditions.

JAXA is one of the global leaders in the field of magnetic suspension technology, boasting the world’s only magnetic suspension wind tunnel capable of practical testing.

Freeing users from the interference of supporting devices, magnetic suspension also enables testing of axisymmetric objects - another significant departure from the traditional wind tunnel approach. Although the wake flows of axisymmetric objects like spheres and cylinders represent fundamental phenomena in the field of fluid dynamics, detailed research on the topic is scarce.

This study aims to clarify the vortex structures in the wake flows of axisymmetric objects (bluff bodies) at high subsonic speeds by taking full advantage of magnetic suspension’s greatest feature: its lack of any support interference. For example, planetary atmospheric re-entry capsules become dynamically unstable from the range of high subsonic speeds to transonic speeds, and the movement of capsules tends to diverge. Although it is known that measurement results for re-entry capsules in conventional wind tunnel testing will be affected by interference from supporting devices, this study will use magnetic support technology to clarify the mechanism of that phenomenon.

At the same time, researchers will evaluate the practicality and reliability of magnetic suspension technology through the application of a wind tunnel testing method which determines dynamic aerodynamic characteristics from the response of full-sized models to excitation. This study will use dynamic testing - the setting where support interference has the most pronounced effects.

The results of a CFD-based analysis of three-dimensional bluff body trailing vortex structure