Study On The Near-field Radiative Heat Transfer In The Three-body System Made Of Nanoporous SiC Hyperbolic Metamaterial

The studies on the near-field radiative heat transfer(NFRHT)have attracted much attention in the past decade since it can surpass the black-body radiation limit and has important potential applications in the scanning thermal microscopy,near-field thermal imaging,heat-assisted magnetic recording,and thermophotovoltaics,etc.The modulation and enhancement of the NFRHT is one of the important research topics in this field.People have also proposed some methods to tune the NFRHT by changing the structures of materials in addition to employ the new-emerging materials.One of the representative methods is to use the three-body system made of three mutual parallel slabs to enhance the heat transfer between the heat source and the heat sink.The other way is to pattern the uniform bulk materials into artificial metamaterials,which will vary the optical characteristics of the bulk materials.This has been proved to be an efficient way to tune the NFRHT.In this thesis,we study the NFRHT in the three-body system made of porous Si C hyperbolic metamaterials.The research contents and the results obtained in this thesis can be classified into the following three aspects:(1)The radiative heat flux can be enhanced obviously in the three-body system compared with that in the corresponding two-body system because the intermediate body can help to transfer the evanescent surface phonon-polaritons(SPh Ps)and hyperbolic phonon-polaritons(HPPs).(2)We study the effect of the thickness of the intermediate body on the radiative heat flux.The heat flux experiences a first increase and then decrease process for the fixed filling fraction as the thickness of the intermediate body increases,and it can reach a maximum value.When the thickness of the intermediate body increases,it can support the transfer of the broad HPPs better,which will result in the enhancement of the radiative heat flux.When the thickness of the intermediate body continues to increase,the intrinsic loss from the porous Si C will hinder the propagations of the both HPPs and SPh Ps,which will lead to the decrease of the heat flux.The maximum heat flux shifts toward larger thickness of intermediate body when the filling fraction increases.(3)The filling ratio of the air hole also has important effects on the radiative heat flux.For the three-body system with fixed intermediate body,heat flux exhibits a slow oscillation behavior rather than a monotonous trend as the filling fraction increases due to the competition between SPh Ps and HPPs.We believe the studies in the thesis are very meaningful to the NFRHT and the corresponding applications.