Riblet · The Development and Construction of a Master Mould for Riblet Construction

The project will consist of the construction of a seamless, precision welded flat master mould manufactured to such a high quality to enable the embossing of painted riblets onto the outer surface of an aircraft. The riblets reduce significantly the drag characteristics under turbulent air flow. Each riblet is spaced 96µm apart and will achieve a sharp angular tip angle of 45 degrees. The depth of the riblet will be set at 48µm. A single riblet geometry seamless master mould (giant master). The consortium partners have joined together to create a combined level of unique expertise capable of manufacturing the precision quality essential for master mould manufacture.The project will engineer and produce CAD-CAM designs for large format master mould or flat shim origination. These will be used to program a state of the art Excimer laser that will write a continuous negative riblet structure onto a polymer sheet. This large format polymer master will be silvered and placed into electroforming tanks to grow a nickel master shim. A series of sub masters and production shims will be grown from the metal master, to deliver metal master mould with dimensions of 1250 x 1250mm.In addition a feasibility study to include sample welds will be undertaken to demonstrate how shims can be welded together to create nominally joinless and seamless shims.