Uploaded April 2020 | Updated September 2026, 1 week ago
The increase in flow speed from the base of a flow into the boundary layer exposes different parts of a grain on the surface to different flow speeds, with flow moving fast over the top of the grain. This flow speed creates a zone of low pressure above the grain. If the pressure is low enough relative to the pressure near the bottom of the grain, it can generate a lift force that is greater than the force of gravity holding the grain down on the surface. This life is due to the Bernouli Effect, which I describe in this video.
The increase in flow speed from the base of a flow into the boundary layer exposes different parts of a grain on the surface to different flow speeds, with flow moving fast over the top of the grain. This flow speed creates a zone of low pressure above the grain. If the pressure is low enough relative to the pressure near the bottom of the grain, it can generate a lift force that is greater than the force of gravity holding the grain down on the surface. This life is due to the Bernouli Effect, which I describe in this video.
