Segment V9.4: Snow Drifts

(Related to Textbook Section 9.2.6 - Effects of Pressure Gradient)

At high Reynolds numbers, non-streamlined (blunt) objects have wide, low speed wake regions behind them.

As shown in a computational fluid dynamics simulation, the streamlines for flow past a rectangular block cannot follow the contour of the block. The flow separates at the corners and forms a wide wake. A similar phenomenon occurs for flow past other blunt objects, including bushes. The low velocity wind in the wake region behind the bushes allows the snow to settle out of the air. The result is a large snowdrift behind the object. This is the principle upon which snow fences are designed. (CFD video courtesy of ITS Corp.)