The influence of seals in the performance of the wing is dramatic. The flow of air through not desired paths can generate turbulence, drag or malfunction of the aerodynamic surfaces. Seals are usually placed in interfaces, very complex areas in which it’s quite difficult to predict the aerodynamic behavior of the airflow and the exact final geometry of the gap to be sealed. So it would be ideal to refine the design of the seals through an iterative development process, with cycles of tests and modifications, to be able to define optimized seals that fulfill their function in a stable manner.
ADDAPTTA SEALS (TI-CS2-2017-CfP07-AIR-02-54) is a project in the AIRFRAME ITD program of Clean Sky II with the aim to develop new concept seals for wing aerodynamic surface, with better performance than currently used and further advantages in terms of cost, time to market and maintainability of the aircraft. This project has been a step forward in the development of a new way of designing and manufacturing seals, taking advantage of the benefits of Additive Manufacturing technologies about rapid prototyping, no need of molds, and ability of introducing modifications with agility and flexibility, allowing tailoring the design of each seal for its particular purpose with the needed optimization loops.
Additive manufacturing technologies and specific materials has been developed for this particular purpose. For achieving these ambitious targets, a number of particularly complex knowledge and expertise are needed, related to aeronautic design, additive manufacturing processes, elastomeric materials specifically formulated for additive manufacturing, and qualification of products under aeronautical standards. Hence, ADATICA Engineering, CSIC-ICTP and APPLUS Laboratories consortium was created.
The main activities carried out by CSIC-ICTP has been related to analyze the elastomeric materials compatible with 3D printing prone to be employed in the elaboration of aircraft seals and formulate printable materials that fulfils the mechanical, environmental and functional requirements defined by the Topic Manager.
On the other hand, Adatica has developed seal design optimization for each seal to improve friction and aerodynamical performances.
Simultaneously, coupons have been manufactured for technology and material testing ensuring that the selected material and manufacturing technology fulfills with the mechanical requirements. Once tested by Applus+, seal coupons where manufactured to develop functional and qualification tests at Applus+ infrastructures.
Lastly, manufactured seals for the wing of FTB#2 Regional Aircraft Flight Demonstrator have been tested and an optimization loop to improve manufactured seals have been carried out. It is important to note that, the results of all functional tests on the optimized designs have been satisfactory, confirming that seals manufactured using additive manufacturing technology are an interesting solution when fast design changes are required.
Some photos of the design, manufacture and tests carried out during the project.
Space reserved for future videos related to the project.