Dielectric nanofluids for electrostatic machines

国家人口的增长对传统和新兴技术中的电动机产生了前所未有的需求。 电力的新用途，包括电动汽车，支持互联网的服务器农场和高速铁路，都对电动机产生了额外的需求。 此外，直接驱动风力涡轮机和无人机可以受益于其传动系统的重新配置。传统的电磁电机使用稀土元素，如镝和钕，其未来的可用性是不确定的。静电电机可以可持续地制造，但在许多应用中需要改进扭矩输出。通过增加马达内流体的介电常数可以实现增加的扭矩。 添加小颗粒可以增加流体的介电常数，但是颗粒-流体混合物对于马达应用来说可能变得过于粘稠。在这个项目中，数学模型和计算机模拟将用于设计具有高介电常数和低粘度的颗粒-流体混合物。 该研究小组将与威斯康星州的化学教育研究所的大学合作，指导本科生在构建静电演示打算为K-12学生。 静电马达所需的大电场可使马达内悬浮液中的粒子在电场诱导下聚集。 颗粒的聚集又导致悬浮液粘度大幅增加，从而降低电机性能。 通过在悬浮液中采用布朗纳米颗粒可以避免颗粒聚集，使得热运动可以克服场诱导力。通过空间稳定化可以避免由于货车范德华力引起的颗粒聚集。 颗粒级模拟将被用来确定颗粒大小和浓度，电场强度和频率，空间层的属性，和宏观介电和流变性能的悬浮液之间的关系。这项工作的结果将使从业人员能够设计有效的纳米颗粒悬浮液用于各种静电电机应用。该奖项反映了NSF的法定使命，并被认为值得通过使用基金会的知识价值和更广泛的影响审查标准进行评估来支持。

Increases in the nation's population have created an unprecedented demand for electric motors in conventional and emerging technologies. New uses of electricity, including electric vehicles, server farms to support the internet, and high-speed rail, have contributed additional demands for electric motors. Furthermore, direct drive wind turbines and drones could benefit from reconfigurations of their drive trains. Conventional electromagnetic motors utilize rare earth elements such as dysprosium and neodymium whose future availabilities are uncertain. Electrostatic motors can be made sustainably, but improvements in torque output are required for many applications. Increased torque can be achieved by increasing the dielectric constant of the fluid within the motor. Adding small particles can increase the fluid's dielectric constant, but the particle-fluid mixture can become too viscous for motor applications. In this project, mathematical models and computer simulations will be used to engineer particle-fluid mixtures that have high dielectric constants and low viscosities. The research team will partner with the University of Wisconsin's Institute for Chemical Education to guide undergraduate students in constructing demonstrations of electrostatics intended for K-12 students. The demonstrations will be used at various venues to engage the public in novel applications of electrostatics.The large electric fields required for electrostatic motors can cause field-induced aggregation of the particles in the suspension within the motor. Aggregation of the particles leads, in turn, to large increases in the suspension viscosity, which diminishes motor performance. Particle aggregation can be avoided by employing Brownian nanoparticles in the suspension, such that thermal motion can overcome the field-induced forces. Aggregation of the particles due to van der Waals forces can be avoided by steric stabilization. Particle-level simulations will be employed to determine the relationships between particle size and concentration, electric field strength and frequency, steric layer properties, and the macroscopic dielectric and rheological properties of the suspensions. The results of this work will enable practitioners to engineer effective nanoparticle suspensions for a variety of electrostatic motor applications.This award reflects NSF's statutory mission and has been deemed worthy of support through evaluation using the Foundation's intellectual merit and broader impacts review criteria.