Increasing the temperature at which jet aircraft engines operate would significantly improve thrust and fuel efficiency with reduced emissions. However, current engines operate within 50 degrees of the inherent melting point of the conventional materials used in engine construction. Thus, new materials capable of operating at higher temperatures for prolonged times must be developed and manufactured.
Ceramics and ceramic matrix composites (CMCs) can operate at temperatures in excess of 2000°F but are difficult to fabricate into the complex shapes required for jet engine use and consequently, novel manufacturing processes must be developed and processing conditions optimized for routine production of complex components.
To support the development of these innovative manufacturing processes, ACES has applied COMSOL Multi - physics to the simulation of manufacturing processes for the production of CMCs. The software has been used to develop specialized multiphysics simulation technologies that describe the infiltration of molten material into a ceramic preform. The range of physical phenomena considered in the analysis is large and includes the following critical mechanisms:
- Unsaturated flow of fluid into a ceramic matrix.
- Capillary fluid flow.
- Chemical reaction between the fluid and the ceramic matrix.
- Volumetric changes associated with the fluid-solid reaction.
- Temperature changes associated with the fluid-solid reaction.
- Residual stress development and its effect on component shape.
COMSOL Multiphysics combines the native capability to conduct fluid flow and structural mechanics solutions with the high degree of flexibility necessary to include the required fluid flow, chemical reaction, and thermal calculations to simulate the critical components of the CMC manufacturing process. Partial differential equations (PDEs) unique to this process have been directly programmed into the software to describe the flow of liquid material into a ceramic matrix. These equations are directly incorporated with COMSOL Multi - physics structural and thermal analyses that are key components of the analysis. The resulting simultaneous solution of multiple physical phenomena provides a more accurate analysis of the process and allows simulation of the interdependent physical phenomena found in the manufacturing process.
Application of simulation tools of this type has allowed designers to reduce cycle time, increase part yield, and optimize the process window for CMC manufacturing. The results of analyses using COMSOL Multiphysics have allowed ACES to resolve production issues with new designs prior to mass production and significantly reduce the time and cost of new product development and manufacture.
This work was performed by Dr. S.P. Yushanov, Dr. J.S. Crompton, and Dr. K.C. Koppenhoefer of ACES using COMSOL software. For more information, Click Here.