发表机构
Arizona State University（亚利桑那州立大学）
机构由 AI 辅助整理，请以论文原文为准。AI 中文总结
本研究通过低温测量验证了未掺杂和钨掺杂VO2可变发射率涂层在空间热控制中的增强辐射散热效果，钨掺杂使相变温度降低25°C，辐射热通量显著提升。
AI 中文摘要
空间热控制对于确保机载设备在规定温度范围内正常运行至关重要。采用可变发射率涂层（VECs）的被动热控制有助于在动态变化的空间热环境中节省功耗。基于二氧化钒（VO2）的可变发射率涂层已被研究用于空间热控制，但其固有的约68°C的相变限制了其在期望较低温度范围的更广泛空间应用。在本工作中，我们通过使用未掺杂和钨掺杂VO2的可变发射率涂层进行低温测量，实验证明了在类空间热环境中增强的辐射散热。制备的未掺杂VEC在相变过程中表现出0.6的大发射率变化，而1 at.%钨掺杂的VEC表现出0.4的可观发射率变化，且相变温度降低了25°C。开发了一套真空低温测量装置，采用液氮冷却的冷指来模拟冷空间热背景，以及一个由尼龙线悬挂的定制样品架。经过仔细校准和验证，低温测试清晰观察到VO2相变时辐射散热显著增强，最高达3.5倍，且通过1 at.%钨掺杂使相变温度降低了25°C。在实际空间热环境中，辐射热通量在相变过程中可进一步增加：未掺杂VO2涂层从55°C到80°C时，从160 W/m²增加到650 W/m²；1 at.%钨掺杂VEC从30°C到55°C时，从175 W/m²增加到493 W/m²。
英文摘要
Space thermal control is critically important to ensure proper operation of on-board equipment in a regulated temperature range. Passive thermal control with variable-emittance coatings (VECs) could help save power consumption in a dynamically changing space thermal environment. Vanadium dioxide (VO2) based VECs have been studied for space thermal control but its intrinsic phase transition around 68°C limits its wider space applications where lower temperature ranges are expected. In this work, we experimentally demonstrate enhanced radiative heat dissipation in space-like thermal environment via cryothermal measurements with VECs of undoped and tungsten doped VO2. The fabricated undoped VEC exhibits a large emittance change of 0.6 across the phase transition, while the 1 at.% tungsten doped one shows an appreciable emittance variable of 0.4 with phase transition temperature lowered by 25°C. A vacuum cryothermal setup is developed with a liquid nitrogen cooled coldfinger to mimic cold space thermal background and a custom-designed sample mount suspended by nylon wires. After careful calibration and validation, greatly enhanced radiative heat dissipation upon VO2 phase transition up to 3.5 times with transition temperature lowered by 25°C from 1 at.% tungsten doping is clearly observed from the cryothermal tests. In the actual space thermal environment, radiative heat flux could further increase across phase transition from 160 W/m2 to 650 W/m2 with undoped VO2 coating from 55°C to 80°C, and from 175 W/m2 to 493 W/m2 with 1 at.% tungsten doped VEC from 30°C to 55°C.
