By the kinematic analysis of flow, and the analysis of drive moment and resistance moment, the rotating speed expression of self-rotating twisted tape was deduced.
通过对换热管内流体的运动分析和自旋扭带的转动力拒与阻力矩分析，推导出扭带的转速计算式。
The basic working principle of magnetic head is described, frequency response curve is given as gap-depletion expression, and gap-depletion is explained to be the main cause that the frequency response range of tape recorder is limited.