The swept flying wing configuration is not adopted widely in the literature for high altitude operation. In previous literature, deferent aerofoils were selected on the basis of a high lift/drag ratio. An additional constraint in the selection of suitable aerofoil sections is the thickness required to hold fuel tanks or batteries and the required structural elements for adequate stiffness. The pitching moment ( C m) should also be considered especially for the flying wing configuration with no tail. Therefore, the aerofoil section needs to be optimised to generate high lift coefficients with a profile drag as low as possible. The required lift coefficient is high when compared to more conventional lower-altitude aircraft, due to reduced air density. The flight profiles of high-altitude long-endurance unmanned air vehicles (HALE UAVs), at high altitudes and moderate flight speeds, represent low-Reynolds number operating conditions. In addition, as expected, this ratio sharply drops after the maximum value of some of these aerofoils.Īerofoil design Low Re Swept flying wing Another observation is that increasing the maximum thickness of the aerofoil leads to a decrease in the maximum lift/drag ratio. According to the set of result obtained so far, the initial observation of the aerodynamic performance of the newly designed aerofoils is that the lift/drag ratio in general is higher than that of the existing ones used in many current-generation high-altitude long-endurance aircraft. Each individual target was run separately to design several aerofoils of different thicknesses that meet the target criteria. Three optimisation targets were set to achieve maximum aerodynamic performance characteristics. The primary target here was to design a number of aerofoils with low pitching moment, suitable for an aft-swept flying wing configuration operating at low Reynolds number in the range of about 0.5 × 10 6.
RC WING AIRFOIL GENERATOR SOFTWARE CODE
The second part contains the optimisation code using a genetic algorithm. This combination is quite efficient in using an optimisation search process because of the capability to define a range of design variables that can quickly generate a suitable aerofoil. PARSEC parametrisation has been used to represent the camber line while the Bezier-curve has been used to select the thickness distribution. The first part generates the aerofoil section geometry using a combination of PARSEC and Bezier-curve parameterisation functions. The tool consists of 2 parts in addition to the aerodynamic solver XFOIL. Something greater than 12% should work.In this paper, 12 new aerofoils with varying thicknesses for an aft-swept flying wing unmanned air vehicle have been designed using a MATLAB tool which has been developed in-house. thin aerofoils can be of the order of 10-12% whereas thick ones can go upto 16-18% at times.but a 'fit' needs to be achieved. This is determined as the percentage of the thickest aerofoil section (which will be at the spar for SPADS) to the chord of the wing. So, the second thing one needs to look at is the aerofoil thickness. So racer etc tend to have thinner aerofoils while slowflyers can have thicker aerofoils.Ĥ. This is only applicable to a limit after which additional drag can cause all types of chaos, including large drop in lift. Thicker aerofoils provide more lift, but the thicker an aerofoil, the slower the plane goes (because of larger drag). Choose flat for slow flyers and trainers, semi-symmetrical for sport trainers and symmetrical for aerobatic trainers that go very fast.ģ. One probably has much simpler choice of choosing between a flat, symmetric and semi-symmetric only The first thing to decide is what kind do you want. Making a rib based design in coro is equally difficult.
Most coro wings use a single spar (SPAD based designs) and hence mimicking perfect numbered aerofoils can be very difficult. Two components (in conjunction) are required to make planes fly properly, the vertical lift and the horizontal speed, always complementing each other within a specified window.Ģ. Here are some things to keep in mind when doing aerofoils:ġ.
RC WING AIRFOIL GENERATOR SOFTWARE TRIAL
The sweetest aerofoil for you airplane can be a matter of trial and testing, and the results are only available once the plane is in-flight (most of us do not have wind tunnel testing equipment ) Getting correct aerofoil shapes with coro can be difficult. In addition to Saurabh's advice, here is some more information:
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