Coatings for Reliable Compact Rotary Engines

Rotary engines offer distinct advantages over piston-driven engines for powering UAVs, particularly due to their high-power density and lower maintenance requirements. However, in harsh marine environments, characterized by humid air with elevated salt and dust concentrations, Wankel-style rotary engines experience significant performance degradation. These conditions accelerate wear and abrasion, promote corrosion, and impair heat transfer, ultimately reducing engine efficiency, durability, and operational lifespan. To address these challenges, Triton Systems, Inc. (Triton) proposes the development of a novel multi-functional coating architecture designed to enhance the wear resistance, corrosion resistance, and thermal management of Wankel rotary engines used in UAVs operating in marine settings. During Phase I, Triton will employ its proprietary solid-state functionally graded material/coating deposition technology to design and fabricate a layered coating structure. This model-guided experimental approach will be informed by multi-physics simulations, allowing for rapid iteration and optimization of material compositions while minimizing the number of physical trials required. The coatings will incorporate functional materials that improve lubricity, resist oxidation, enhance wear resistance, and ensure thermal stability under extreme conditions. Coated test coupons will undergo rigorous evaluation using standardized methods to assess corrosion resistance, adhesion strength, wear behavior, and microstructural integrity. These tests will validate coating quality and ensure the metallurgical control needed to meet target performance metrics and component longevity. Triton will collaborate closely with a rotary engine OEM during Phase I to ensure alignment between coating properties, test protocols, and the OEMís pre-qualification requirements for material and process maturation. In Phase II, Triton will extend this partnership to include Navy and industrial end-users. The focus will shift to optimizing the coating process and validating the formulation through engine-level testing under realistic operational conditions. This strategic progression will position Triton to advance toward process qualification and integration into target platforms during Phase II enhancement and Phase III activities.