Unsteady flow through a curved channel with roughness in the form of sinusoidal corrugations is examined. The flow is generated by a time periodic pressure gradient. The fluid velocity is both time and space periodic, as a result of the oscillatory pressure gradient and the geometry of the curved channel. The effects of the inherent parameters; physical and geometrical, on the velocity field and the volumetric flow rate are determined analytically. For low frequency of the oscillatory pressure gradient, the flow is essentially similar in characteristics to that of the steady flow driven by a constant pressure gradient, but for high frequency, the flow is substantially modified, when compared with the steady flow. The corrugations increase the total flow rate for small corrugation wavenumber, and further enhancement is obtained when the phase difference between the corrugated curved walls is increased. For large corrugation wavenumber, a contrary effect of the corrugations is found; the flow rate decreases irrespective of the phase difference. However, we have shown that for sufficiently high corrugation wavenumber and oscillation frequency, the effect of the phase difference would be negligible.

检查流经弯曲通道的非稳态流动，该弯曲通道的粗糙度为正弦波状波纹。该流量由时间压力梯度产生。由于振荡压力梯度和弯曲通道的几何形状，流体速度在时间和空间上都是周期性的。固有参数的影响；在速度场和体积流量上的物理和几何形状都可以通过解析确定。对于振荡压力梯度的低频，该流量在本质上与由恒定压力梯度驱动的稳定流的特性相似，但是对于高频，当与稳定流量相比时，该流量被实质性地修改。对于小波纹波数，波纹会增加总流速，当波纹状弯曲壁之间的相位差增大时，可获得进一步的增强。对于较大的波纹波数，发现了相反的波纹效应。流量减小而与相位差无关。但是，我们已经表明，对于足够高的波纹波数和振荡频率，相位差的影响可以忽略不计。