Near Field Radiative Heat Transfer Between Parallel Plates With Flat And Rough Surfaces

The properties of thermal radiation exchange between hot and cold objects can be strongly altered if they interact in the near-field where electromagnetic coupling occurs across gaps smaller than the wavelength of thermal radiation,the interference effect of the wave and the photon tunneling effect are particularly significant.The classical macroscopic radiation transfer theory is based on geometrical optics and ignores the interference effect of Light.Current studies have shown that radiation heat transfer is about 5 to 6 orders of magnitude larger than the result calculated by Stefan-Boltzmann law when the distance between the two sources decreases conventionally to nanometer level.Characteristics of anisotropic multi-layer coupling and radiative heat transfer between plates with rough surface is studied in this article.In this article near-field radiative heat transfer between anisotropic multilayer structures analyzed using parallel-plate configuration with gradient refractive index distribution combined with effective medium theory approximation.Using this approach near-field radiative heat transfer between different surfaces i-e flat-rough surface,rough-rough surface have been analyzed and compared with flat-flat surface.Silicon Carbide,Silicon dioxide,Aluminum are the object of study.Based on the theory of fluctuation and dissipation,a combination of Maxwell's equations and dyadic Green's function is used to calculate the near-filed radiative heat transfer.The reflection and transmission coefficients for s and p polarization at each interface calculated with the assistance of surface admittances for each plate.Convergence test for anisotropic multilayer structure have also been conducted for the validity of work.Enhancement has been observed in radiative heat transfer with roughness effect for silicon carbide and silicon dioxide while for Aluminum short reduction have been observed in radiative heat transfer with roughness effect.Besides parallel plates with rough-rough surface the radiative heat transfer for flat-rough surface is also calculated and it is observed that the radiative heat transfer for silicon dioxide is bit greater than rough-rough surface.Enhancement of heat transfer over a broad frequency region is also observed with roughness effect.Near-field radiative heat transfer is one of the most encouraging way for enhancing the efficiency and power output of energy harvesting systems such as thermo-photovoltaics system.