Re: The truth about "ram air"
Turbulent flow does have its uses when cooling, lamina flow does not scour the surface to be cooled and the boundary surface layer impedes efficient cooling. Turbulent flow removes the boundary, which is slow moving and the turbulent air or water contacts the surface to be cooled.
The boundary layer can be seen on the hood of your car when it is raining, the rain water slowly rolls rearward instead of moving at the speed of the car. When the water reaches the limit of the boundary it flies off in an instant. This is more evident on some cars than others.
You want lamina flow over your car but not over surfaces to be cooled.
Lamina flow occurs when the volume passing through a pipe is insufficient, increasing the flow or reducing the size of the pipe will create turbulent flow. The design secret is to achieve the desired cooling rate with the least amount of fluid.