The benefits of riblets on reducing drag has been established and reverified over the years since the technologys inception in the 1980s. Unfortunately, transitioning riblets from machined aluminum panels to a format that can be utilized for large scale aerospace applications has been unsuccessful. Applique riblet films required significant application time and specialized workers. Utilizing photocurable coatings is a complex process that is beyond current industry capabilities. MTech believes there is an opportunity to leverage commercialized laser technology and apply it in a novel way to produce riblets directly into an already coated and cured surface utilizing direct laser interference patterning (DLIP). This technology would enable an economically feasible large-scale production of riblets on the range of 50-100 microns by a contact/wear-free continuous process. MTech has adopted specific technical objectives that define the research required to verify the geometric detail and resulting chemical composition of DLIP applied riblets. MTech will research and demonstrate the micro scale geometry capabilities of the DLIP process on a standard cured MIL-PRF-85285 Type IV topcoat. The MIL-PRF-85285 coating containing the riblets will tested for conformance with the specification requirements to include, but not limited to, the following: gloss, tape resistance, adhesion, heat resistance, color, fluid resistance, solvent resistance, cleanability, weather resistance, and impact flexibility. These tests will confirm the durability of the riblets in the uniquely harsh operational environment that Naval aircraft experience. The impacts of riblets on routine maintenance will be invested and the maintenance level of any maintenance tasks will be determined. A detailed BCA will be conducted highlighting the benefits of riblet production via DLIP versus projected reduction in fuel consumption. These key objectives will demonstrate the necessary technological maturity of the DLIP process to move rapidly to a commercialized application of both military and commercial aircraft.
Benefit: By reducing parasitic drag on the surface of an object, riblets can decrease fuel usage and CO2 emissions up to 8%. In commercial aviation and shipping alone over $34 billion in fuel and 225 million tons of CO2 emissions annually so the savings could be as high as $2.7 billion dollars and 18 million tons of CO2 on an annual basis. This proposal marries the demonstrated benefits of riblets with the advancements in laser ablation to derive a practical, affordable and robust application of riblets. The result of this development will be a mature solution that has significant environmental and financial benefits across the aerospace, marine, and wind engery markets.
Keywords: resilient riblets, resilient riblets, biomimicry, Riblets, laser ablation, parasitic drag
