Biomimetic fuel filtration for air vehicles based on Ricochet separation inspired by manta rays

Aviation fuel containing particles can cause severe damage to engine systems, making efficient filtration mechanisms essential for air vehicle fuel systems. Conventional aviation fuel filters often suffer from clogging, requiring periodic replacement, and they introduce a pressure drop as fuel passes through. To address these challenges, this study applied a new filtration mechanism found in the gill structure of manta rays to design the fuel filter. Manta rays employ their wing-shaped lobes to deflect plankton away during the filtration process. This mechanism, known as ricochet separation, facilitates particle separation by utilizing the stall characteristics of a series of lobes at high angles of attack, where particles follow the separated flow induced by stall. In this study, we turn this unique solid–liquid separation method into a practical application. Computational fluid dynamics and particle trajectory simulation are employed to analyze the effects of four key geometric variables—maximum camber, angle of attack, filter lobe arrangement length, and the number of filter lobes—on filter performance across various flow rates. Utilizing response surface methodology, we approximate the filter performance curve based on these variables. The optimized filter lobe geometry, tailored for a specific flow rate, offers several advantages, including high particle collection efficiency, minimal pressure loss, non-clogging operation, reduced weight increase, and the ability to capture particles smaller than the pore size. These advantages position the proposed biomimetic filter as an effective solution for high-flow aviation fuel filtration systems operating under strict volume and performance constraints.