Riblet Microfabrication Method for Drag Reduction

Advances in Riblets Design

“…It provides a review of experimental tests conducted using various instrumentation technologies, fabrication methods, and testing strategies [25,45,56,66,80,[82][83][84]. Over the past decades, researchers have introduced innovative techniques, resulting in new insights into the applicability of riblets in industrial settings [84][85][86]. Considering the focus of this paper on aviation, the discussion centers on two main areas: wind tunnel tests and in-flight experiments.…”

“…During the past few decades, the fabrication of riblet geometries has been implemented through several different methods in order to fulfill the requirements of experimental research studies. An array of research activities introduced different procedures of fabrication as a part of their studies on the effectiveness of riblets [55,65,80,[108][109][110]; however, a few studies have been specifically devoted to investigating different methods of industrial fabrication [45,66,84,86,104]. Research works that are developed in academic environments have been mostly conducted with cost-effective fabrication techniques, using small-size flat plates or extruded airfoils, while in commercial applications, some other parameters such as weight, time of implementation, durability and maintenance would be more important [18,56].…”

“…As an example, for near transonic commercial aircraft, due to the reduction in density and other aerodynamic parameters, micro-scales of height (around 80 µm) are required for optimum drag reduction [50]. By focusing on the aviation industry, microfabrication techniques were investigated during the past decades, with successful results [19,66,86,120].…”

Climate Impact Mitigation Potential of Novel Aircraft Features

“…In the past, traditional manufacturing and maintenance procedures meant that riblets were not economically feasible for conventional aircraft. However, with the advent of new manufacturing processes such as direct contactless microfabrication, these costs have been steadily decreasing, thus reducing the negative impact on DOC [24,25]. Riblets are now reaching commercial maturity, as demonstrated by the recently proposed application of a BASF co-developed riblet film to Lufthansa Cargo's complete fleet of Boeing 777F freighters [26].…”

“…However [21] indicates that in most scenarios the majority of the gains of NLF are realised after such optimisations are performed. For riblets, on the other hand, the cost of maintenance has been steadily decreasing, due to advancements in manufacturing techniques such as direct contactless microfabrication [23][24][25].…”