BACKGROUND
High-speed unmanned aircraft are currently used for a variety of time-critical missions but are limited by several key factors. Turbine rotational speeds are constrained by mechanical stress and thermal limitations. High operating temperatures combined with higher rotational speeds can lead to undesired malfunctions within a turbojet engine. Additionally, current small turbojet engines have a very low Mean Time Between Overhaul (MTBO) of only around 25 hours of operation. There is also a limited worldwide production capacity for these engines, none of which reside in the United States. An advanced manufacturing technique for small scale turbojet engines could prove vital in improving performance limitations that currently exist, as well as reducing MTBO and facilitating ease of maintenance.
SUMMARY OF TECHNOLOGY
Researchers at Oklahoma State University have developed an advanced manufactured small turbojet engine that improves performance, production, and maintenance for high-speed unmanned aircraft. This advanced manufacturing enables a larger design space to improve optimal turbine performance and durability, reduce Mean Time Between Overhaul (MTBO), and facilitate ease of field maintenance. The turbine material consists of high-strength nickel alloy, adding strength and high temperature properties to the turbojet engine design. Design parameters such as stage loading coefficient, blade stress, and rotor/stator solidity were carefully considered. The final design matches the desired exit Mach values while still meeting performance metrics in a viable range. Ultimately, batch production with additive manufacturing enables large-scale production, reduces unit cost, and allows for rapid prototyping for different applicable turbojet engines.
POTENTIAL AREAS OF APPLICATION
- Micro turbojet engine production especially in the US
- Improved unmanned aircraft performance in time-critical missions
- Rapid prototyping of different turbojet engines
MAIN ADVANTAGES
- Enables higher operating temperatures and turbine rotational speeds
- Encourages large-scale production
- Reduces Mean Time Between Overhaul (MTBO) and facilitates ease of field maintenance
STAGE OF DEVELOPMENT