A front edge wooden dowel and two middle spares give the wing its strength a tailing edge supports the flaps, gives the tailing edge airfoil shape and also lends strength to the wing. The spacing was determined to be every 2 inches, this distance was determined from studying commercial available planes and a previous years plans for a riser wing. This year the team has decided to use the rise constructions method which entails creating many thin airfoils, out of balsa wood, and spacing each along wooden spars through out the wing. Other years they have used foam core with a little better success but not much. ![]() One year the covering was Kevlar attached with an epoxy, the epoxy soaked in to the foam making the wing heavier then designed, the plane did not do well that year. The foam core is just that lightweight foam that is shaped, with a hot wire, in to the airfoil design, and then covered with various materials to improve strength. The foam core is and easy construction and has been used with varying degrees of success in the past. There are to main construction methods for building a model aircraft wing foam core and risers, each with there benefits and drawbacks. The wing makes up the largest area of the plane but is among the lightest. Design for construction takes into account the decisions made the materials to use and way in which parts can be fabricated. Once all of the components of the wing are decided on, and the major calculations concerning the characteristics of the plane are completed, the design for the construction can begin. The dihedral angle improves stability in side to side motion as well as stability in turning. A dihedral angle is the common angle used on model aircraft and has been used many times in previous years. The wing angle gives many improving characteristics to the airfoil including stability and performance see appendix G. The rectangular wing shape was chosen mainly for its easy of build, though its stall characteristics are worst then that of the elliptical. The wing shapes considered by the group were rectangular, tapered, elliptical, swept and elliptical each with there own positive and negatives see appendix G. The wing shape and the angle with which it makes parallel to the ground improve some of the characteristics of airfoil chosen. The airfoil is the most important part of the wing creating lift but there many decisions to be made before the wing design is done. This data can then be used in the various calculations in order to determine the characteristics of the plane see the calculations section for further details. The graphs generated from the ModelFoil software can be found in appendix B-1 showing comparisons between CL vs. Comparing the data received from the software, and other calculations it is determined that the S1223 is the best airfoil with a high coefficient of lift and a small coefficient of drag. This maximizes the ability of a plane with a heavy load to take off within the given output of engine constraints. The plane to be designed is a heavy lift cargo plane and there for must have a high coefficient of lift, even at low speeds, and has a low coefficient of drag. The program was able to generate many of the key numbers that are important to engineers in designing the wing, top among these is the coefficient of lift and drag at different angles of attack. The team then used an airfoil software, ModelFoil, and calculations to compare the characteristics of many airfoils. This team looked into what airfoils previous teams at this school used, to see if they used similar airfoils and how well the airfoils preformed. When looking into the airfoil, like any portion of the plane, it is important to first do research into the subject and to look at what people have done before. The airfoil is a shape that has characteristics that create lift. The first thing to do when designing a wing is to look at the airfoil shape that the wing will take. ![]() The wing that we have designed this year has incorporated all the knowledge that people have discovered about wings over the last one hundred years. ![]() One hundred years ago two men discovered how to create a light weight wings and using other light weight material they were able to be the first people to fly under power. The wing is the most important part any plane, it is the component that creates lift and allows flight.
0 Comments
Leave a Reply. |
AuthorWrite something about yourself. No need to be fancy, just an overview. ArchivesCategories |