NUS Enterprise

Two-Phase Stepped Fin Heat Sink

Technology #11337n

Two-Phase Stepped Fin Heat Sink

Inventors : Assoc. Prof. Lee Poh Seng, Mr. Karthik Balasubramanian

Department of Mechanical Engineering

Industry Problem

Two-phase flow instabilities (flow rate and system pressure) may arise when boiling occurs in conventional size channels and more so in a parallel array of multiple micro/mini-channels.

These undesired effects must be controlled or mitigated as they (1) induce mechanical vibrations in the system, (2) degrade the heat transfer performances (premature dryout, critical heat flux limitation) etc.

Also, two-phase pressure drop is very high and it increases the pumping power requirements significantly which affects the pump sizing.


To address the challenges of these flow instabilities, the research team developed novel heat sinks to stabilize the flow boiling process within the micro/mini channels and achieve a better heat transfer performance, by modifying the geometry. This geometry allows room for the vapor to expand span wise and hence flow downstream without appreciable flow reversal, acting like a diffuser.

Value Proposition

•  Reduced pressure drop and wall temperature fluctuations

•  Low pumping power requirements

•  Reliable heat transfer performance due to reduced fluctuations.

•  Passive technique without need for any further active devices. Hence no additional cost incurred.

Other Potential Application

•  Microprocessors, integrated Circuits (ICs), 3D ICs

•  Electric vehicle (EV), hybrid EV

•  High power battery packs, windmill gear box, wind turbine waste heat recovery

•  Concentrator photovoltaic, solar energy collector

•  Defense application avionics

For more information, contact:

NUS Industry Liaison Office

  :+65 6516 7175




This research is supported by National Research Foundation (NRF2012NRF-POC001-024)

Ref : ID11337N