It is also indicated that with transition fixed at about 10% chord the drag levels were similar to other airfoils with turbulent boundary layers. The minimum drag for the airfoils was found to range from 0.0045 to 0.0051, representing far lower levels than any airfoil dominated by turbulent boundary layer. It was found that all the airfoils showed the presence of a drag bucket close to design conditions and long lengths (in some cases about 70%) of natural laminar flow at Reynolds number 6.7 million. Laminar flow airfoils were originally developed for the purpose of making an airplane fly faster. FlexFoil utilizes shape morphing to change the wings airfoil shape during flight. Their design Mach numbers were 0.8, 0.76, 0.72 and 0.68 respectively and the design chord Reynolds number was 12.5 million. Interesting to see more on what they can achieve there. The airfoils have maximum thickness to chord ratios of 0.10, 0.13, 0.16 and 0.21 and were designed for a lift coefficient of CL = 0.6. An everyday example is the slow, smooth and optically transparent flow of shallow. Prandtl applied the concept of the laminar boundary layer to airfoils in 1904. This flow profile of a fluid in a pipe shows that the fluid acts in layers that slide over one another. This report contains an analysis of the experimental results obtained from four supercritical natural laminar flow (NLF) airfoils investigated in the NAE High Reynolds Number Test Facility. The velocity profile associated with laminar flow resembles a deck of cards. The usual definition of a laminar flow airfoil is that the favorable pressure gradient ends somewhere between 30 and 75 of chord. All airfoils must have adverse pressure gradients on their aft end. Laminar flow airfoils are designed to have long favorable pressure gradients. National Research Council Canada, National Aeronautical Establishment 'A favorable pressure gradient is required to maintain laminar flow. A Summary of Transonic Natural Laminar Flow Airfoil Development at NAE
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