Question

The way a fluid flows can be characterized as laminar or turbulent or some mix of laminar and turbulent. The "Reynolds Number" is a calculation engineers use to describe the laminarity or turbulence of the flow. The above photograph from a wind tunnel shows air flow around a simple airfoil - laminar flow with evenly space streamlines (low Reynolds number) and turbulent flow with "corkscrewing streamlines (high Reynolds number). Questions: 1) The lift on an aircraft wing (see Bernoulli's principle)is more efficient when the air flow across the wing is laminar rather than turbulent. For more efficient lift do you think the wing surface should be smooth or rough?

Answer 1

Turbulent Flow Laminar Flow

Laminar Flow is that the smooth, uninterrupted flow of air over the contour of the wings, fuselage, or alternative elements of associate degree craft on the wing. streamline flow is most frequently found at the front of a efficient body and is a very important think about flight. If the sleek flow of air is interrupted over a wing section, turbulence is made which ends up in a very loss of carry and a high degree of drag. associate degree surface designed for minimum drag and uninterrupted flow of the physical phenomenon is termed a stratified surface.

The Laminar (streamline) flow theory restrained the event of a symmetrical surface section that had an equivalent curvature on each the higher and lower surface. the planning was comparatively skinny at the forefront and more and more widened to some extent of greatest thickness as so much aft as potential. the idea in exploitation Associate in Nursing surface of this style was to take care of the adhesion of the boundary layers of air flow that area unit gift on the wing as so much aft of the forefront as potential. On traditional airfoils, the physical phenomenon would be interrupted at high speeds and also the resultant break would cause a flow over the rest of the foil. This turbulence would be complete as name the purpose of most speed, at which era the management surfaces and craft flying characteristics would be affected. The formation of the physical phenomenon could be a method of layers of air fashioned one next to the opposite, i.e.; the term stratified springs from the lamination principle concerned.