STTR Phase I: 3D Printed Vapor Cooled Liquid Hydrogen Storage Tank for Use in Enterprise Level Unmanned Aerial Vehicles

STTR第一阶段项目将开发用于无人机的3D打印液氢燃料箱。无人机目前采用长续航时间低可靠性汽油发动机，或短续航时间高可靠性电力推进。如果采用合适的储氢方法，氢燃料电池可以提供长时间、高可靠性的推进能力。通过该项目开发的创新储氢系统，燃料电池电动汽车可以通过减少排放和促进地面和空中能源独立来促进国民健康和福利。该项目将为电动无人机开发一种新型液氢储罐，这将提高武装部队监视平台的可靠性和性能，降低美国服务人员的风险，同时确保我们国家的国防安全。同时，该平台还可以对关键的能源和交通基础设施进行检查，并在自然灾害中成为应急人员的情报和通信平台，从而促进国家福祉。此外，该项目开发的关键技术将通过展示工程塑料在低温（-238°F）环境下的能力和性能，扩大增材制造的实用性。这种低温等级的3D打印聚合物部件具有广泛的影响，包括降低成本，从医疗设备和航天器到药物和食品加工的低温依赖技术领域。直到现在，增材制造的聚合物从未用于低温应用。正确选择聚合物共混物，测试和选择轻质防渗膜，以及新型保温材料的热特性是项目成功的关键。由于大多数低温研究，如氢通过聚合物的-423°F渗透，自20世纪60年代以来尚未进行研究，因此需要广泛的低温工程和测试经验，才能将现代材料和制造方法应用于该项目。该项目的目标是通过测试金属化聚合物薄膜的氢渗透性，以及将其经济有效地应用于隔热板或罐壁的制造方法来填补知识空白。虽然之前的研究已经确定了一种抗低温热循环的聚合物混合物，但微开裂的可能性尚未得到彻底解决，将在本项目中进行评估。以前从未在商业低温应用中使用的新型绝缘材料将被热表征并集成到原型储罐中。该项目将通过完成液氢燃料填充和测量质量蒸发率来测试计算流体动力学模型的性能来结束。

This STTR Phase I project will develop 3D printed liquid hydrogen fuel tanks for unmanned aerial vehicles (UAVs). UAVs are currently powered by long endurance low reliability gasoline engines, or short endurance highly reliable electric propulsion. Hydrogen fuel cells offer the potential for long endurance highly reliable propulsion if the proper hydrogen storage method is used. Through the innovative hydrogen storage system developed by this project, fuel cell electric vehicles can advance national health and welfare through reduction of emissions, and promotion of energy independence both on the ground and in the air. This project will develop a new class of liquid hydrogen storage tanks for electric UAVs that will increase the reliability and performance of surveillance platforms in the armed forces, reducing risk to American service personnel while they secure the defense of our nation. The same electric platforms will promote the national welfare by enabling the inspection of key energy and transportation infrastructure and serving as intelligence and communications platforms for first responders during natural disasters. In addition, the key technology developed in this project will expand the utility of additive manufacturing by demonstrating the capabilities and performance of engineered plastics in cryogenic ( -238°F) environments. Such cryogenic rated 3D printed polymer parts have wide ranging impacts, including cost reduction, across cryogenic dependent technology areas from medical devices and spacecraft to drug and food processing.Additively manufactured polymers have never been used in cryogenic applications until now. The correct selection of polymer blend, testing and selection of a lightweight impermeable membrane, and thermal characterization of novel insulation materials are critical to project success. Since most cryogenic research, such as -423°F permeation of hydrogen through polymers, has not been studied since the 1960s, extensive cryogenic engineering and testing experience is required to apply modern materials and manufacturing methods to the project. The objectives of this project will fill knowledge gaps by testing metallized polymer films for hydrogen permeability, as well as manufacturing methods to cost effectively apply it to insulation panels or tank walls. While prior research has identified a polymer blend that is robust to cryogenic thermal cycling, the possibility of microcracking has not yet been thoroughly addressed and will be evaluated in this project. Novel insulation materials never before used in commercial cryogenic applications will be thermally characterized and integrated into the prototype tank. This project will conclude by completing a liquid hydrogen fuel fill and measuring the mass boil-off rate to test computational fluid dynamic modeled performance.