Apparatus and method for enhanced heat transfer

Abstract

One embodiment of the system is implemented as a device for two-phase heat transfer. This device comprises a chamber containing a fluid, where a heated wall makes up a portion of the chamber. The device also comprises an actuator that emits pressure vibrations. The pressure vibrations dislodge vapor bubbles that form at the heated wall due to the heat in the wall.

1 . A device for cooling a heated object, comprising: 
 a chamber containing a fluid;    a heated wall comprising a portion of said chamber; and    an actuator, said actuator emitting pressure vibrations for dislodging vapor bubbles from a surface of said heated wall.    
   
   
       2 . The device of  claim 1 , wherein said fluid comprises water.  
   
   
       3 . The device of  claim 2 , wherein said fluid further comprises methanol in addition to water.  
   
   
       4 . The device of  claim 1 , wherein said actuator comprises an ultrasonic actuator and said pressure vibrations comprise ultrasonic pressure waves.  
   
   
       5 . The device of  claim 1 , wherein said actuator comprises: 
 a diaphragm;    a piezoelectric element attached to said diaphragm; and    a circuit for driving said piezoelectric element, said driving circuit comprising a sinusoidal function generator and an amplification chip.    
   
   
       6 . The device of  claim 5 , wherein said diaphragm comprises a ceramic disk.  
   
   
       7 . The device of  claim 1 , wherein said chamber further comprises: 
 an inflow pipe at a first wall of said chamber, said inflow pipe in fluid communication with an interior of said chamber;    an outflow pipe at a second wall of said chamber, said outflow pipe in fluid communication with an interior of said chamber; and    wherein said fluid in said chamber moves out from said chamber through said outflow pipe and into said chamber through said inflow pipe.    
   
   
       8 . The device of  claim 7 , further comprising: 
 a reservoir in fluid communication with said chamber via said inflow pipe and said outflow pipe, said reservoir containing said fluid.    
   
   
       9 . The device of  claim 1 , wherein said heated wall comprises a heat sink material.  
   
   
       10 . The device of  claim 9 , further comprising a heat-producing object adjacent to said heat sink material.  
   
   
       11 . The device of  claim 10 , wherein said heat-producing object comprises a microelectronic circuit.  
   
   
       12 . The device of  claim 1 , wherein said heated wall comprises a portion of a microelectronic circuit.  
   
   
       13 . The device of  claim 1 , further comprising a synthetic jet actuator in said chamber.  
   
   
       14 . A method for cooling, comprising the steps of: 
 providing a chamber with a fluid;    generating heat in a wall of said chamber;    causing the formation of vapor bubbles at said wall of said chamber;    emitting pressure vibrations into said fluid; and    said vapor bubbles dislodging from said wall of said chamber due to the pressure vibrations.    
   
   
       15 . The method of  claim 14 , further comprising the step of circulating said fluid through said chamber.  
   
   
       16 . The method of  claim 15 , wherein said emitting step comprises the steps of: 
 providing an actuator, said actuator having a diaphragm;    vibrating said diaphragm at a resonant frequency of said diaphragm; and    causing pressure waves to move through said fluid from said diaphragm, said pressure waves impinging upon said wall.    
   
   
       17 . The method of  claim 14 , further comprising the steps of: 
 providing a fluid reservoir, said fluid reservoir in fluidic communication with said chamber;    moving said fluid from said chamber to said reservoir and back to said chamber; and    cooling said fluid in said reservoir.    
   
   
       18 . The method of  claim 17 , wherein said moving step comprises: 
 providing a fluidic pump; and    pumping said fluid from said fluid reservoir to said chamber, and from said chamber back to said fluid reservoir.    
   
   
       19 . A cooling device, comprising: 
 a chamber containing a fluid    a heat source supplying heat into said fluid of said chamber; and    an actuator for emitting pressure vibrations into said fluid.    
   
   
       20 . The device of  claim 19 , wherein said heat source comprises a wall of said chamber.  
   
   
       21 . The method of  claim 20 , wherein said actuator comprises a diaphragm vibrating at a resonant frequency of said diaphragm.