![]() Cars Īn inverted Clark Y airfoil was used on the spoilers of the Dodge Charger Daytona and Plymouth Superbird. The stability of a rocket during flight is the one of the most crucial factors from the perspective of a design engineer. Inexperienced modellers are more readily able to build model aircraft which provide a good flight performance with benign stalling characteristics. The Clark Y is appealing for its near-flat lower surface, which aids in the construction of wings on plans mounted on a flat construction board. Applications range from free-flight gliders through to multi-engined radio control scale models. 1.75, for the NACA airfoils was obtained for the forward-camber 230 airfoil series for a thickness ratio of 2 percent, which is probably the optimum thickness ratio. The Clark Y has found favor for the construction of model aircraft, thanks to the flight performance that the section offers at medium Reynolds number airflows. Cp c Cd cz Cm Z/d M R t x SYMBOLS pressure coefficient airfoil chord section drag coefficient section lift coefficient. The Clark Y was chosen as its flat bottom worked well with the design goal of a low radar cross-section. The Northrop Tacit Blue stealth technology demonstrator aircraft also used a Clark Y. Louis are two of the better known aircraft using the Clark Y profile, while the Ilyushin Il-2 and Hawker Hurricane are examples of mass-produced users of the Clark YH. The Clark YH airfoil is similar but with a reflexed (turned up) trailing edge producing a more positive pitching moment reducing the horizontal tail load required to trim an aircraft. The flat lower surface is not optimal from an aerodynamic perspective, and it is rarely used in modern designs. The flat bottom simplifies angle measurements on propellers, and makes for easy construction of wings.įor many applications the Clark Y has been an adequate airfoil section it gives reasonable overall performance in respect of its lift-to-drag ratio, and has gentle and relatively benign stall characteristics. The airfoil has a thickness of 11.7 percent and is flat on the lower surface aft of 30 percent of chord. Clark using thickness distribution of the German-developed Goettingen 398 airfoil. The profile was designed in 1922 by Virginius E. The coefficient of drag decreased with Reynolds number, whereas the coefficient of lift remained almost unchanged.Clark Y is the name of a particular airfoil profile, widely used in general purpose aircraft designs, and much studied in aerodynamics over the years. The effect of variation in Reynolds number was minor. Over the range of parametric variation in this study, both lift and drag coefficients increased with an increase in the angle of attack. The discrepancies are attributed to the selection of turbulence model and 2-D steady state flow. Specifically, the simulated values of drag coefficients were 30 to 100% higher than the experimental values. However, some discrepancies were observed and highlighted for the coefficient of drag. An excellent agreement was noted for the coefficient of lift. Lift and drag coefficients were calculated from the simulations and compared with their experimental values. Grid independency was established and study was done by varying Reynolds number and angle of attack over a range of 5x10 5 to 2x10 6 and -15° to 15°, respectively. A two-dimensional steady state simulation was conducted along with SST k-ω turbulence model. Fluid flow over a NACA airfoil (NACA 0012) was simulated using ANSYS FLUENT.
0 Comments
Leave a Reply. |
AuthorWrite something about yourself. No need to be fancy, just an overview. ArchivesCategories |