由两平行平板组成的突扩通道，尺寸如图所示。流动为层流。入口流速均匀，入口温度均匀，通道壁温均匀。分子粘性、密度已知，求：通道中流体的速度分布、温度分布、密度分布及压力场。-Formed by two parallel plates sudden expansion channel, size as shown. Flow is laminar flow. Uniform inlet velocity, inlet temperature uniformity, the channel wall