Studies of a very high efficiency cryogenic launcher

Studies of a very high efficiency electromagnetic launcher

“…However, since at low speeds this force is negligible in comparison with the electromagnetic force, the expression that (strictly) is only valid at high speed was used throughout the calculations. It is only at high speeds, when the distance between the driving coil and the projectile is great and the currents begin to decay, that the reduced electromagnetic force and the increased drag force become comparable [16].…”

“…Figure 11 shows the projectile velocity during the experiment 106 (described in table 3 of next chapter) as predicted by both codes. The terminal velocity is predicted by the simple model with the usual accuracy of 1-2% (predicted terminal velocity 1756 m s −1 , experimentally measured 1789 m s −1 [16], the corresponding error is 1.85%). However, because the actual velocity measurement cannot be done but during the acceleration phase, the subtle variations of the projectile speed due to the interaction between the electromagnetic force and the drag force as evidenced by the filamentary model cannot be predicted by the simple code.…”

“…Table 3 gives the initial conditions for a typical experiment (experiment 106) from the extensive launcher investigation that was undertaken. The system design is based on the optimization criteria presented above and was described in [16]. The coil/projectile dimensions (inner/outer diameter and thickness) were best achievable when the projectile was laser cut from thin aluminium plate.…”

“…The coil/projectile dimensions (inner/outer diameter and thickness) were best achievable when the projectile was laser cut from thin aluminium plate. The capacitor bank was charged to its maximum voltage (30 kV) and the switch resistance and the system inductance were minimized during an extensive research programme [13][14][15][16]. Cryogenic cooling of the projectile [16] minimized its initial resistance.…”

“…During recent years, a combined experimental/theoretical investigation at Loughborough has aimed to establish unequivocally whether an efficiency exceeding 50% can be obtained during an electrostatic to kinetic energy conversion process, with an axial ring-type induction launcher clearly being the natural vehicle for this. Brief details of results obtained in the early stages of the research have already been published [13][14][15], and it has been demonstrated experimentally [16] that the objective can be met. A description is now given of the simple model of a single-turn launcher that was used to optimize the design of the experimental launcher.…”