在工业和自然界中的管道系统里,流体所经弯曲管道是一个普遍现象。弯曲对这些流动的入口长度和压力降等重要方面都有影响。很多大血管都是弯曲的——其中突出的例子是主动脉,通往头部的大动脉就是从主动脉弓分支出去的。在这里,除弯曲的流动外还有另一个重要特征,即壁面的剪切,因为它可能与血管损伤和动脉发生粥样硬化的病灶式分布有关系。在伯克利,过去的十五年中,我们一直在研究弯曲管道里的流动,最终目的是确定大血管进口段的脉动流。我们第一个主要的分析是建立了弯曲管道中大Dean数下的定常发展流动的模型。(这个工作是与Singh In industrial and natural plumbing systems, it is a common phenomenon that the fluid bends the pipe. Bending affects these important aspects of inlet length and pressure drop of these flows. Many large blood vessels are curved - the prominent case is the aorta, the aorta that leads to the head branches off from the aortic arch. Here, besides the curved flow, there is another important characteristic, namely the shearing of the wall, as it may be related to the lesion-like distribution of blood vessel damage and arterial atherosclerosis. At Berkeley, we have been studying the flow in curved pipes for the past fifteen years, with the ultimate goal of determining the pulsating flow at the large vessel inlet section. Our first major analysis is the establishment of a model for the steady flow under large Dean numbers in curved pipe. (This job is with Singh