end wall boundary layer

例句：

1. 1. The boundary layer is the thin layer of air near the surface of a liquid or solid.
   边界层是液体或固体表面附近的薄空气层。
2. 2.The boundary layer is important in understanding the flow of fluids.
   边界层在理解流体流动中非常重要。
3. 3.The boundary layer is responsible for the heat transfer between the gas and the liquid.
   边界层负责气体和液体之间的热传递。