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Realizing the thinnest hydrodynamic cloak in porous medium flow
Mengyao Chen1, Xiangying Shen1,2, Lei Xu1
1The Department of Physics, The Chinese University of Hong Kong, Shatin, Hong Kong, China.
Innovation (Cambridge (Mass.))
|June 16, 2022
Summary
Researchers developed an ultrathin cloak for fluid environments, reducing a multi-layer cloak to a single isotropic layer. This breakthrough enables effective near-field invisibility and object concealment in fluids.
Area of Science:
- Physics
- Materials Science
- Fluid Dynamics
Background:
- Transformation mapping theory enables the design of invisible cloaks by maintaining invariant propagation equations under coordinate transformations.
- Conventional cloaks use multi-layer anisotropic materials, which can be challenging to realize, especially for thin cloak designs requiring extreme material property variations.
Purpose of the Study:
- To design an ultrathin, shell-shaped cloak for flow fields in porous media.
- To overcome the material challenges associated with traditional thin cloaks by reducing complexity.
Main Methods:
- Applied a bilayer cloak design method, integrating the inner layer with the obstacle.
- Utilized the properties of flow fields in porous media to simplify cloak design.
- Tailored the permeability of the porous medium to achieve required material parameters.
Main Results:
- Reduced a multi-layer anisotropic cloak to a single isotropic layer.
- Created the thinnest shell-shaped cloak reported to date, with a thickness-to-shielding region ratio of 0.003.
- Successfully realized challenging material parameters for an ultrathin cloak.
Conclusions:
- The developed ultrathin cloak design is effective for near-field invisibility in fluid environments.
- This method offers a practical approach to concealing objects within fluids.
- The findings advance the field of cloaking technology for physical fields.
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