طراحي و بهينه سازي ساختار مجراهاي خنك كن در قطعات الكترونيكي با استفاده از تئوري ساختاري

چكيده انگليسي :

Constructal Design and Optimization of Cooling Conduits in Electronics Dalir Menbary d menbary@mech iut ac ir 10 th April 2011 Department of Mechanical Engineering Isfahan University of Technology Isfahan 84156 83111 Iran Degree M Sc Language FarsiSupervisor Mohammad Reza Salimpour salimpour@cc iut ac irAbstractThe construtal theory is an idea that says the generation of flow configuration is a physical phenomenon This theory is explains that for a flow system to persist in time to survive it must evolve in such a waythat it provides easier and easier access to the currents that flow through it This law is the basis for theconstructal theory of the generation of flow configuration in nature Today this entire body of workrepresents a new extension of thermodynamics the thermodynamics of nonequilibrium systems withconfiguration Actually this theory pays attention to the geometry and configuration of the flow systems Using constructal theory in engineering is observable in different fields such as electronics cooling physics civil engineering information systems etc A well known structure of constructal theory aideddesign is the tree shaped network The important aim of tree shaped networks is to make suitableconnection between one point source and sink and a continuum an infinity of points volume and area and obtain as architectures for maximum access The cooling of electronics is done by three mechanismsof heat transfers conduction convection and radiation In convective cooling two goals are targeted first optimizing thermal resistance and second optimizing flow resistance In fact the constructal theoryleads to the optimal geometrical features of flow paths so that the resistances thermal resistance andflow resistance are minimized In this research the flow paths are designed between some points locatedequidistantly on an internal ring and some other points located equidistantly on an external ring The fluidenters the conduits at the internal ring flows outward and exists at the edge of the disc The coolant issingle phase and the regime of fluid flow is laminar and fully developed in every channel The heatgeneration throughout the body is uniform while the global volume of channels is constrained In thepresent thesis Y shaped structures with pairing or bifurcation emdedding in a disc body wereinvestigated The disc of this study has non dimensional internal radius 0 0 0 1 0 2 and 0 3 The bestgeometric notions of tree shaped structures are sought to have the minimal overall flow and thermalresistances The overall flow resistance constitutes of two parts i distributed pressure losses and ii local pressure losses In this work the effect of various parameters upon these resistances and hence thethermal and flow performances are investigated These parameters include number of ducts 0 initiatingfrom the internal ring number of branching internal radius of disc and mass flow rate From the results itis disclosed that among the different parameters affecting the resistances the mass flow rate has the mosteffect on thermal resistance whilst the effect of mass flow rate on the flow resistance is slight Moreover it is seen that increasing the complexity more levels of pairing lead to the reduction of the thermalresistance and increment of the flow resistance Also it was found out that the increasing of internalradius is led to the decrease in both thermal and flow resistances Keywords Constructal Theory Thermal Resistance Flow Resistance Tree Networks ElectronicsCooling Geometric Features Convection Optimization

منبري، دلير

طراحي و بهينه سازي ساختار مجراهاي خنك كن در قطعات الكترونيكي با استفاده از تئوري ساختاري

ساختار درختي , مقاومت جريان , مقاومت حرارتي , دماي ماكزيمم بي بعد , نرخ دبي جرمي بي بعد نرخ توان پمپاژ