Trajectory Optimization of Electric Aircraft Subject to Subsystem Thermal Constraints
Trajectory Optimization of Electric Aircraft Subject to Subsystem Thermal Constraints
复制标题
受子系统热约束的电动飞机轨迹优化
DOI：
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发表时间：
2017
期刊：
影响因子：
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通讯作者：
J. Gray
中科院分区：
文献类型：
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作者：
Robert Falck;J. Chin;Sydney L. Schnulo;J. M. Burt;J. Gray
电动飞机提出了一个独特的设计挑战，因为它们缺乏一种简单的方法来排除动力系统的废热。虽然传统的飞机会将大部分多余的热量排出废气流，但对于电动飞机来说，这不是一种选择。为了研究这一挑战对电动飞机设计和性能的影响，我们为NASA X-57电动试验台飞机开发了一个电气子系统模型。然后，我们将该模型与简单的2D飞机动力学模型相耦合，并使用Legendre-Gauss-Lobatto配置最优控制方法来找到具有和不具有热约束的飞机的最优轨迹。结果表明，X-57的排热系统设计良好，可实现最大射程和最大效率，而无需偏离最佳轨迹。通过降低冷却能力或需要更快的光来强调热约束对性能的影响最小，因为轨迹优化技术能够找到荣誉热约束的光路径，其与标称最佳轨迹具有相对较小的偏差。
Electric aircraft pose a unique design challenge in that they lack a simple way to reject waste heat from the power train. While conventional aircraft reject most of their excess heat in the exhaust stream, for electric aircraft this is not an option. To examine the implications of this challenge on electric aircraft design and performance, we developed a model of the electric subsystems for the NASA X-57 electric testbed aircraft. We then coupled this model with a model of simple 2D aircraft dynamics and used a Legendre-Gauss-Lobatto collocation optimal control approach to find optimal trajectories for the aircraft with and without thermal constraints. The results show that the X-57 heat rejection systems are well designed for maximum-range and maximum-efficiency flight, without the need to deviate from an optimal trajectory. Stressing the thermal constraints by reducing the cooling capacity or requiring faster flight has a minimal impact on performance, as the trajectory optimization technique is able to find flight paths which honor the thermal constraints with relatively minor deviations from the nominal optimal trajectory.