一维亥姆霍兹线圈仿真，绕线区域由矩形生成，即长方体，更好的模拟了多匝线圈的情况。开发平台为comsol5.2(One dimensional Helmholtz coil simulation, the winding area is generated by rectangle, namely cuboid, better simulation of multi turn coil. The development platform is comsol5.2)