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, comprising:
 a chamber containing a fluid;   a heat source disposed outside of said chamber and in thermal communication with a first wall thereof; and   an actuator which is spaced apart from said heat source and which dislodges vapor bubbles from said first wall by emitting pressure vibrations.   
     
     
         2 . The device of  claim 1 , wherein said fluid comprises water. 
     
     
         3 . The device of  claim 2 , wherein said fluid further comprises methanol. 
     
     
         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 . (canceled) 
     
     
         8 . (canceled) 
     
     
         9 . The device of  claim 1 , further comprising a heat sink. 
     
     
         10 . (canceled) 
     
     
         11 . (canceled) 
     
     
         12 . The device of  claim 1 , wherein said heat source comprises a portion of a microelectronic circuit. 
     
     
         13 . The device of  claim 1 , further comprising a synthetic jet actuator disposed in said chamber. 
     
     
         14 . The device of  claim 1 , wherein said heat source is adapted to generate sufficient heat to cause the formation of vapor bubbles on a surface of said first wall. 
     
     
         15 . (canceled) 
     
     
         16 . (canceled) 
     
     
         17 . (canceled) 
     
     
         18 . (canceled) 
     
     
         19 . A device, comprising:
 a chamber containing a fluid;   a heat source which is in thermal contact with said fluid; and   an ultrasonic actuator, spaced apart from said heat source, which is in vibrational communication with said fluid.   
     
     
         20 . The device of  claim 19 , wherein said heat source comprises a wall of said chamber. 
     
     
         21 . The device of  claim 20 , wherein said actuator comprises a diaphragm vibrating at a resonant frequency of said diaphragm. 
     
     
         22 . The device of  claim 19 , wherein said pressure vibrations comprise ultrasonic pressure waves. 
     
     
         23 . The device of  claim 19 , 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.   
     
     
         24 . The device of  claim 1 , wherein said actuator is disposed across from said first wall. 
     
     
         25 . The device of  claim 24 , further comprising a synthetic jet actuator disposed adjacent to said heated wall. 
     
     
         26 . The device of  claim 25 , wherein said synthetic jet actuator is adapted to direct a synthetic jet essentially parallel to the surface of said heated wall. 
     
     
         27 . A device for cooling a heated object, comprising:
 a chamber containing a fluid and having a heat source whose surface forms a wall of the chamber; and   emitting means, spaced apart from said heated wall, for emitting pressure vibrations suitable for dislodging vapor bubbles from a surface of said heated wall.   
     
     
         28 . The device of  claim 1 , wherein said actuator is disposed on a second wall of said chamber, and wherein said first and second walls are opposing walls.