Study On The Heat Transport Characteristics Of The Asymmetric Fractal-like Bifurcation Structures

The bifurcation network structures widely exist in nature and our daily life they and have attracted the attention of many researchers in recent years because of its special advantages in many applications. Many researchers have studied the properties of the symmetric bifurcation network structures, but most of the actual structures are asymmetrical. In this thesis, we study the heat transport characteristics of the asymmetric fractal-like bifurcation network.In this paper, firstly we introduce the related theory of the fractal geometry, the asymmetric bifurcation network, the heat transfer and the Murray's law.In chapter 2, based on the structural characteristics of the bifurcation of the network and the basic theoretical knowledge of heat transfer and fluid dynamics, the minimal resistance configuration of the asymmetrical bifurcation network structure for a fixed total volume or a fixed total surface area was deduced. Then the length ratio and radius ratio between the mother bifurcated channel and the daughter bifurcated channel was introduced, and the dimensionless thermal resistance's expression of this network was obtained.In chapter 3, based on the previous work, the dimensionless effective thermal conductivity expression of the network structures was deduced and the relationship among the parameters was analyzed in this paper. The results show that the dimensionless effective thermal conductivity is a function of the radius ratio, the length ratio and the bifurcation number of the network, and has nothing to do with other factors. Also, the research results reveal that in order to reduce the thermal conductivity of the asymmetrical bifurcated network structure, the conditions need to meet that one of the daughter bifurcated channel have a larger radius ratio and length ratio, and the other daughter bifurcated channel has the opposite condition.In chapter 4, the main conclusions of the present work are summarized, and some potential directions on future research of the transport characteristics of the asymmetric fractal-like bifurcation network are presented.