Hydrodynamic characterization of a passive shape memory alloy valve

[摘要] Next generation high-performance electronics will have large heat fluxes (>102W/cm2) and an alternative approach to traditional air cooling is required. An attractive solution is micro-channel cooling and micro-valves will be required for refined flow control in the supporting micro-fluidic systems. A NiTi Shape Memory Alloy (SMA) micro-valve design was hydrodynamically characterized in this work to obtain the valve loss coefficient (K) from pressure measurements. The hydrodynamic characterization was important as in the flow regime of the micro-fluidic system K is sensitive to Reynolds number (Re) and geometry. Static replicas of the SMA valve geometry were studied for low Reynolds numbers (110-220) in a 1x1 mm CSA miniature channel. The loss coefficients were found to be sensitive to flow rate and decreased rapidly with an increase in Re. The SMA valve was compared to a similar gate micro-valve and loss across both valves was of the same order of magnitude. The valve loss coefficients obtained in this work are important parameters in the modeling and design of micro-fluidic cooling systems.

[发布机构] CTVR, Stokes Institute, University of Limerick, Limerick, Ireland^1;Thermal Management Research Group, Bell Labs, Alcatel-Lucent, I-Dublin, Ireland^2

[效力级别] 无线电电子学

[关键词] Attractive solutions;Hydrodynamic characterization;Large heat flux;Loss coefficients;Low Reynolds number;Micro fluidic system;NiTi shape memory alloys;Valve geometry