Manufacturability of Aircraft Winglet for Wind Tunnel Testing

Abstract

The form, shape and dimensions of the scaled down winglet model become small and thin bringing complexity to manufacturing. The trailing edge tapers to a thickness varying from 0.065mm to 0.099mm along its length. The mounting portion of the winglet is provided with a close tolerance having a slot gap of 5mm and a depth of 35 mm with an angle. Additionally, wind tunnel models require good surface finish on the aerodynamic surfaces and this involves adopting a manufacturing strategy with a control over on the metal cutting parameters to be implemented on a three axes CNC machining centre. The winglet surface is divided into segments in order to handle the cutting forces on the varying aerodynamic cross section. Various metal cutting parameters such as tool path, cutter diameter, feed rate, depth of cut, spindle speed, etc., are evaluated by monitoring segments where the metal cutting is carried out [1] and flow of chips observed. Fixtures and lugs are planned effectively to accommodate the machining of the angular slot in a three axes machining centre itself. Routing of operations to handle the varying thin sections and realisation of the close tolerance slot has enabled a reliable manufacturing approach in an economical way.