In-situ fill fraction adjustment of oscillating heat pipe

A method of selectively switching an oscillating heat pipe (OHP) device between an ON state and an OFF state, said method comprising:

• fluidly coupling an OHP device comprising a plurality of OHP microchannels to a switching control fluid reservoir via a fluid transfer conduit, wherein there is a two-phase working fluid disposed within the OHP microchannels and the switching control fluid reservoir;
• selectively adjusting a temperature of a switching control fluid reservoir via a reservoir temperature control device to create a pressure differential between the switching control fluid reservoir and the OHP device;
• and
• transferring working fluid between the OHP device and the switching control fluid reservoir via the created pressure differential to change a fill fraction of the OHP device to selectively switched the OHP device between an ON state and an OFF state.

A method of selectively switching an oscillating heat pipe (OHP) device between an ON state and an OFF state, said method comprising:

• fluidly coupling an OHP device comprising a plurality of OHP microchannels to a switching control fluid reservoir via a fluid transfer conduit, wherein there is a two-phase working fluid disposed within the OHP microchannels and the switching control fluid reservoir;
• selectively creating a pressure differential between the switching control fluid reservoir and the OHP device;
• and
• transferring working fluid between the OHP device and the switching control fluid reservoir via the created pressure differential to change a fill fraction of the OHP device to selectively switched the OHP device between an ON state and an OFF state.