Aerodynamic guidelines in the design and optimization of new regional turboprop aircraft

This paper aims to provide some guidelines in the aerodynamic design and optimization of future regional turboprop aircraft with about 90 passengers. Currently there are no configurations on the market of this type, thus a typical 70 passengers turboprop aircraft is taken as reference starting point. The most critical aircraft components in terms of aerodynamic drag contribution and possible improvement are highlighted and an automatic procedure manageable trough MATLab® is described. This interfacing procedure allows importing and modifying geometries using interpolating curves and surfaces via NURBS. Within the optimization loop, any new geometry is analyzed trough the panel code solver until optimized shapes are found. Wing–fuselage junction (also called “Karman”), undercarriage pod, fuselage nose and wing-tip device have been investigated and estimation of performance advantages has been computed. Design of the winglet is presented highlighting performance improvements during the entire mission profile. Finally two different turboprop configurations are proposed: the first with a 4-abreast fuselage arrangement and the second with 5-abreast, highlighting pros and cons of each configuration