Magnetic field and inductance gradient at the circular railgun

Magnetic flux density and inductance gradient are main quantities. These quantities are a function of the rails shapes, railgun caliber and dimensions of rails. In this paper, the circular railgun has been simulated with the finite element method. In the circular railgun, inductance gradient is a function of the opening angle of the rail, inner and outer radius of the rails. Inductance gradient is computed for inner radius equals 1cm and outer radius equals 2.67 cm as a function of opening angle of the rails. It is computed for inner radius equals 1.5 cm and opening angle of the rails equal 90° outer radius as a function of outer radius. Then it is computed for outer radius equals 5 cm and opening angle of the rails equal 90° outer radius as a function of inner radius. All results are shown in the some figures. For opening angles equal 60°, 90° and 120° inductance gradient are founded as a function of outer radius divided by inner radius that is shown in figure. Finally, can be shown with analytical proving the magnetic flux density in the middle of the circular railgun and it has a descending function according to central angle.