English

Problem On The Acoustic Cloak By $0$ to $R_1$ Transformation

Classical Physics 2017-11-17 v8 Applied Physics

Abstract

The 00 to R1R_1 radial spherical coordinate transformation method can be making electromagnetic (EM) invisible cloak. However the cloak by transformation optic has infinite speed and exceeding light speed etc fundamental difficulties. In this paper, we discover problem on acoustic cloak by transformation and prove that in the 00 to R1R_1 radial spherical coordinate transformation, the pressure wave field P(rp)=P(r)P(r_p)=P(r) is invariant, in the physical inner spherical surface boundary r=R1r=R_1, P(R1)P(R_1) is not zero. the acoustic field propagation penetrate into the inner sphere r<R1r < R_1.Therefore, the inner sphere r<R1r < R_1 can not be cloaked. The GL simulation figures of the pressure acoustic wave propagation penetrate into the inner sphere rR1r \le R_1 are presented in figure 1 to figure 12.The pressure wave is setting to zero that cause the scattering wave to disturb incident pressure acoustic wave outside of the outer sphere rR2r \ge R_2 that make the whole sphere rR2r \ge R_2 will be deltected. GL method simulation is presented in figure 13. we discovered and proved that 00 to R1R_1 sphere radial transformation can not be used to induce acoustic no scattering cloak.

Keywords

Cite

@article{arxiv.1706.05375,
  title  = {Problem On The Acoustic Cloak By $0$ to $R_1$ Transformation},
  author = {Jianhua Li and Feng Xie and Lee Xie and Ganquan Xie},
  journal= {arXiv preprint arXiv:1706.05375},
  year   = {2017}
}

Comments

18 pages, 112 formulas and 2 figures in this paper, Welcome comments from colleagues. It is academical publication for open review. Please colleague send comments and question to me by email [email protected]. If colleague use this paper, please be sure cite my paper in his papers. The Paper is different from other papers