Influence of the magnetic core on efficiency of multistage gauss gun
In order to assess an influence of magetic core on efficiency of multistage reluctance accelerator, I performed a set of calculations for initial velocity of 60 m/s. All other parameters were taken from the system which had been subject for investigation at 0 m/s initial velocity here. The one exception was that the controlled switch was taken into account, so a new parameter - its deactivation time - was introduced and varied to achieve a maximum output velocity.
Besides, the influence of excitation energy, "pumped" to the coil from capacitors, was investigated, and also the activation coordinate (i.e. the distance from the projectile to the frnt end of the coil when the switch is "on"). The latter is negative which is a feature of non-zero initial velocity (the activation occurs for some time before projectile reaches the coil).
The magnetic core thickness was 5 mm. Results are on the pictures below.
As one can see, the effect is not distinguishing strongly from one for zero initial velocity - the core gives about 20% effiiency gain in actual energy range (10 J and more). It is expectedly more for less energies, which is essential for less magnetized ferromagnetic.
Also, it shоuld be emphasized that the coordinate of activation, which accords to maximum efficiency, shifts out from the coil with addition of the core. It is understandable because the core increases an effective diameter of the coil and expands its magnetic field in axial direction.