![]() XFLR5 also allows tail fins and elevators to be added and also a second wing (typically for bi-plane configurations). These results can be exported to a text file for subsequent analysis or comparison with other results. Figure 13.3 shows the results of a typical sweep through the available angles of attack. If this happens, modify the chosen sweep of angles to ensure that all angles can be fullyįigure 13.2 Results of XFoil analysis sweep for the NACA 64-201 foil at Mach 0.17 as computed with XFLR5.ĭealt with. The sequence of angles of attack can then be specified and analyzed and checked for any errors the most likely error is that one of the sections along the wing goes outside the previously computed set of polars for a given wing AoA (a local section lift coefficient is requested that is above what can be achieved for the section at the given operating point).If desired, inertia terms, nonstandard atmospheric properties, and extra drag items can next be added.The computed reference area, span, and chord length should be checked against what is expected.3D panels have to be used to generate full pressure maps for structural analysis, however). The desired analysis is defined by using type 1 again but now with the chosen operational speed and one of the four available analysis types (Lifting Line Theory, Horseshoe Vortex, Ring Vortex, or 3D Panels the first of these does not allow viscous affects to be included, so we prefer to use the 3D Panel approach as the computational costs are still slight, but this is possible only if the tail and fin are not included.Alternatively, the wing is created directly in XFLR5 with manual inputs, in the “Plane Define a new plane” area, where a title and description can be set before defining the main wing each section requires values for y, chord, (leading edge) offset, dihedral, twist, section name (from the drop-down of sections built earlier), and the number and distribution of panels (typically between 10 and 30 in cosine or sine pattern).(Note: if this step is carried out before the chosen section has been loaded, a simple planform diagram is created instead.) The wing is loaded under the “Wing and Plane Design” menu by reading an XML file as created by the AirCONICS system for the wing of interest this comprises the locations and sizes of sections along the wing and references the previously chosen airfoil section.Figure 13.2 shows the results for the NACA 64-210 section at Mach 0.17). The system simply aborts any combinations that cannot be converged by XFoil such a sweep typically takes 2 or 3 min. This builds an internal database of results using XFoil from which the wing analysis can be generated (typical values are Reynold’s numbers from 100 000 to 6 million in steps of 100 000 with AoA sweep from -4° to 16°. The foil section is then analyzed with the “XFoil Direct Analysis” menu in batch mode analysis type 1 is used to specify a range of section operational Reynold’s numbers and an increment in these along with a sweep through likely section angles of attack.AirCONICS provides a good selection of basic foils, the UIUC database has many more. The desired foil section to be used in the wing design is chosen along with the operational Mach number for the wing the section is loaded into XFLR5 via the “Direct Foil Design” menu.To analyze a simple wing with XFLR5, the following steps are used: ![]() ![]() XFLR5 does, however, readily permit calculation of the aircraft’s dynamic stability, which can be used to check whether elevator and fin sizes and positions are acceptable given the likely mass, inertias, and flight speeds. Effects between widely spaced lifting elements (such as wings and tails) can be dealt with, such methods cannot accurately predict the benefits of slotted flaps and other boundary layer control systems. ![]()
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