System and method for maintaining efficiency of a fractal heat sink

Abstract

A heatsink comprising a heat exchange device having a plurality of heat exchange elements each having a surface boundary with respect to a heat transfer fluid, having successive elements or regions having varying size scales. According to one embodiment, an accumulation of dust or particles on a surface of the heatsink is reduced by a removal mechanism. The mechanism can be thermal pyrolysis, vibration, blowing, etc. In the case of vibration, adverse effects on the system to be cooled may be minimized by an active or passive vibration suppression system.

What is claimed is: 
     
         1 . A heatsink comprising:
 a base structure configured to interface with a heat source;   a heat transmissive body, configured to receive heat from the base structure; and   a heat transfer surface surrounding the heat transmissive body configured to transfer heat to a surrounding heat transfer medium, the heat transfer surface having a plurality of tapered branched protrusions having different cross sectional areas with respect to distance from a preceding branch point.   
     
     
         2 . The heatsink according to  claim 1 , wherein the heat transfer surface comprises a plurality of successive branch points, and the cross sectional area of the heat transfer surface bounded by the heat transfer surface of a branch diminishes across the successive branch points. 
     
     
         3 . The heatsink according to  claim 1 , wherein a shape of the heat transfer surface is branched, and optimized according to a model of flow of the surrounding heat transfer medium to provide a larger cross sectional area of respective branches that encounter higher flow rates of the surrounding heat transfer medium than respective branches that encounter lower flow rates of the surrounding heat transfer medium according to the model. 
     
     
         4 . The heatsink according to  claim 3 , further comprising a blower configured to move heat transfer medium over the heat transfer surface, wherein a spatial flow of heat transfer medium is inhomogeneous. 
     
     
         5 . The heatsink according to  claim 3 , further comprising a variable flow rate blower configured to move heat transfer medium over the heat transfer surface, wherein a spatial flow of heat transfer medium is inhomogeneous and having turbulent regions which vary as a function of flow rate. 
     
     
         6 . The heatsink according to  claim 1 , further comprising a variable flow rate blower configured to move heat transfer medium over the heat transfer surface, wherein flow rate of heat transfer medium is controlled in dependence on at least an acoustic emission. 
     
     
         7 . The heatsink according to  claim 6 , wherein the flow rate of heat transfer medium is controlled in dependence on at least a temperature. 
     
     
         8 . The heatsink according to  claim 1 , further comprising:
 a variable flow rate blower configured to move heat transfer medium over the heat transfer surface;   a vibrational sensor configured to detect vibrations; and   a control configured to control the flow rate of the blower in dependence on the detected vibrations.   
     
     
         9 . The heatsink according to  claim 1 , further comprising:
 a variable flow rate blower configured to move heat transfer medium over the heat transfer surface;   a sensor configured to detect an accumulation on the heat transfer surface; and   a control configured to control the flow rate of the blower in dependence on the detected accumulation.   
     
     
         10 . The heatsink according to  claim 1 , further comprising:
 a variable flow rate blower configured to move heat transfer medium over the heat transfer surface;   a computational model of an interaction of the heatsink and the heat exchange medium; and   a control configured to control the variable flow rate of the variable flow rate blower in dependence on the computational heat exchange model.   
     
     
         11 . The heatsink according to  claim 1 , further comprising a component configured to control changes of a direction of heat transfer medium flow over time. 
     
     
         12 . The heatsink according to  claim 1 , wherein the heat transfer surface has a fractal geometry defined by an iterated function system. 
     
     
         13 . A heatsink comprising:
 a base structure configured to interface with a heat source;   a heat transmissive body, configured to receive heat from the base structure; and   a heat transfer surface surrounding the heat transmissive body configured to transfer heat to a surrounding heat transfer medium, the heat transfer surface having a plurality of tapering branched protrusions, each tapering branch dividing into at least two secondary branches at a respective branch point, the secondary branches having different cross sectional areas.   
     
     
         14 . The heatsink according to  claim 13 , wherein the heat transfer surface of at least one secondary branch comprises a successive branch point, and a plurality of tertiary branches emanating from the secondary branch point. 
     
     
         15 . The heatsink according to  claim 13 , further comprising a variable flow rate blower configured to induce a flow of heat transfer medium over the heat transfer surface; a sensor configured to sense at least one of a thermal and a mechanical characteristic; and an automated control, configured to control a flow rate of the heat transfer medium induced by the variable flow rate blower, in dependence on at least the at least one of a thermal and a mechanical characteristic. 
     
     
         16 . The heatsink according to  claim 15 , wherein the sensor comprises a vibrational or acoustic sensor and the automated control is configured to control the variable flow rate in dependence on at least an output of the vibrational or acoustic sensor. 
     
     
         17 . The heatsink according to  claim 13 , further comprising:
 a variable flow rate blower configured to induce a variable flow rate of the heat transfer medium over the heat transfer surface;   a sensor configured to estimate an amount of accumulation on the heat transfer surface; and   a control configured to control the variable flow rate of the blower in dependence on the estimated amount of accumulation.   
     
     
         18 . The heatsink according to  claim 13 , further comprising:
 a variable flow rate blower configured to induce a variable flow rate of the heat transfer medium over the heat transfer surface;   a computational model of an interaction of the heatsink and the variable flow rate of the heat exchange medium; and   a control configured to control the variable flow rate of the variable flow rate blower in dependence on the computational heat exchange model.   
     
     
         19 . The heatsink according to  claim 13 , wherein the heat transfer surface has a fractal geometry. 
     
     
         20 . A heatsink control method, for controlling cooling of a heat source by a heatsink comprising a base structure configured to interface with the heat source; a heat transmissive body, configured to receive heat from the base structure; and a heat transfer surface surrounding the heat transmissive body, configured to transfer heat to a surrounding heat transfer medium, the heat transfer surface having a plurality of protrusions into the heat exchange medium;
 the method comprising:   detecting a flow induced characteristic of the heat transfer medium;   detecting a temperature;   controlling a variable rate of flow of the heat exchange medium in dependence on at least the temperature and the flow induced characteristic of the heat transfer medium.