Distance in the direction of propagation of a periodic wave between two successive points at which the phase is the same ( at the same time ) 在周期波传播方向上在同一时间连续两个相位相同的点之间的距离。
2.
The numerical simulations show that the phase plane and amplitude plane in orthotropic fluid - saturated porous media is not paralleled to each other any more though the dispersion caused by the fluid is omitted . it is one kind of non - homogeneous wave . the maximum attenuation is no longer 指出由于介质的各向异性，尽管忽略了流体粘度引起的粘度耗散，正交各向异性液饱和多孔介质中瑞利波的相平面和幅平面亦不再重合，为非均匀波，最大的衰减不再沿波传播方向。
