论文标题
营养角对进攻缸内部流动及其发电机作用的影响
The effect of nutation angle on the flow inside a precessing cylinder and its dynamo action
论文作者
论文摘要
实验探索了螺旋角对进攻缸内流动的影响，并将其与数值模拟进行比较。重点是直接强制M = 1 Kelvin模式的典型分解，以增加进动比（Poincaré数），以及层流和湍流之间的伴随过渡。与具有90°营养角的参考案例相比，进型旋转会导致较早的崩溃，而在逆行案例中，强制模式也继续存在以较高的庞加莱数字。一项运动型发电机研究在很大程度上取决于轴对称双滚动模式的出现和强度，这表明自我激发条件对营养角度和庞加莱数量的敏感依赖性。发现90°角的最佳发电机条件可能会转移到较高的雷诺数的稍微逆行进动。
The effect of the nutation angle on the flow inside a precessing cylinder is experimentally explored and compared with numerical simulations. The focus is laid on the typical breakdown of the directly forced m=1 Kelvin mode for increasing precession ratio (Poincaré number), and the accompanying transition between a laminar and turbulent flow. Compared to the reference case with a 90° nutation angle, prograde rotation leads to an earlier breakdown, while in the retrograde case the forced mode continues to exist also for higher Poincaré numbers. Depending largely on the occurrence and intensity of an axisymmetric double-roll mode, a kinematic dynamo study reveals a sensitive dependency of the self-excitation condition on the nutation angle and the Poincaré number. Optimal dynamo conditions are found for 90° angle which, however, might shift to slightly retrograde precession for higher Reynolds numbers.
