A high-efficiency concentric tubular-type resistojet with potential application to short-term orbit-raising maneuvers has been fabricated by 3-D printing and demonstrated. The propellant flows through multiple layers of cylindrical shells, with this structure also functioning as a single-piece heater. A 6-cm-high cylinder was realized with a wall thickness of 0.2 mm, using Inconel 718. A nodal thermal analysis was performed to identify the upper-limit current at a temperature limit of the wall material, and it was revealed that an outlet gas temperature of 871 K can be achieved with 77 A of current at 0.2 g/s of mass flow rate. The designed heater was combined with a boron nitride insulator and a stainless-steel housing, and thrust was measured in a vacuum chamber with nitrogen as the propellant. At a mass flow rate of $0.2\mathrm{g}/\mathrm{s}$ and 75 A of current, an outlet temperature of 747 K, a specific impulse of 108 s, and a heater efficiency of 72% were achieved. These results with nitrogen propellant were used to predict the performance of a tungsten-made resistojet with a hydrogen propellant, and a specific impulse of over 700 s can be expected at a heater temperature of 2000 K.

已经通过 3D 打印制造并演示了一种高效的同心管式阻力喷射器，具有潜在应用于短期升轨机动的潜力。推进剂流过多层圆柱形炮弹，这种结构也起到单件加热器的作用。使用 Inconel 718 实现了一个 6 cm 高、壁厚为 0.2 mm 的圆柱体。通过节点热分析来确定壁材温度极限下的上限电流，并揭示了一个出口871 K 的气体温度可以在 77 A 的电流和 0.2 g/s 的质量流量下实现。设计的加热器与氮化硼绝缘体和不锈钢外壳相结合，并在以氮气为推进剂的真空室中测量推力。在质量流量为$0.2\mathrm{G}/\mathrm{秒}$电流为75 A，出口温度为747 K，比冲为108 s，加热器效率为72%。使用氮气推进剂的这些结果用于预测使用氢气推进剂的钨制阻力喷射器的性能，并且在 2000 K 的加热器温度下可以预期超过 700 s 的比冲。