Vibration/Shock-Tolerant Capillary Two-Phase Loop Technology for Vehicle Thermal Control

Two-phase thermal management technologies are promising cooling solutions for the high performance electronics in the next generation military and commercial vehicles. However, vibrations (∼ 10Grms in commercial automobile engines and transmissions) and shocks (30G to 1,200G in military combat vehicles, caused by gun firing, ballistic launch and abrupt maneuvering) present a severe challenge to any capillary-driven (i.e., passive) two-phase devices. A low-cost, vibration/shock-tolerant Capillary Two-Phase Loop (CTPL) technology was developed as a cooling alternative for the future military vehicles. Unlike the traditional two-phase cooling loops such as Loop Heat Pipes (LHP) and Capillary Pumped Loops (CPL), the CTPL offers the following advantages: (1) lower manufacturing cost by sintering the evaporator wick in-situ; (2) improved tolerance to vibrations and shocks due to the improved mechanical strengths of the in-situ sintered wick; (3) improved heat flux performance because of the non-inverted meniscus wick. Small-scale proof-to-concept CTPL prototypes were successfully tested up to 120W of heat input and under multiple, consecutive shocks of up to 6.6G.