Fluid/Structural Interaction Tools for Liquid Rocket Engines

ABSTRACT: Liquid rocket engine (LRE) turbopumps operate in complex and often harsh flow regimes that range from cavitating liquid flows in pumps to shock-containing compressible flows in turbine components. The unsteady flow phenomena seen by structural components establish design limitations associated with mean loadings and cyclic fatigue. The current LRE design process simplifies the modeling of these phenomena due to the lack of fully-coupled fluid/structural interaction (FSI) analysis tools, potentially leading to excessive conservatism in the design. The current analysis methods used in turbomachinery tend to oversimplify the complex interactions between fluids and structures in that they are mostly"one-way"couplings. The proposed innovation is to move the state-of-the-art analysis of liquid rocket engine turbomachinery past the current one-way coupling schemes towards a fully-coupled FSI simulation. This goal will be achieved through the development of methods that allow the close coupling of commercially available nonlinear computational structural dynamics and computational fluid dynamics tools. Future enhancements can be implemented in these codes that are specifically tailored to turbomachinery. The objectives of the Phase I program are to demonstrate feasibility of tools and models and to identify potential verification and validation cases relevant to liquid rocket engine conditions. BENEFIT: Next-generation launch programs will require propulsion systems that deliver high thrust-to-weight ratios, increased trajectory-averaged specific impulse, reliable overall vehicle systems performance, low recurring costs, and improved crew safety. The development of a comprehensive set of validated FSI methods and tools provides a unique opportunity to optimize design, realize additional system efficiencies, reduce weight and/or cost, and increase part life in future generations of liquid rocket engine (LRE) designs. The benefits of the technology and potential commercial applications are not limited solely to the LRE industry. The methods developed in this SBIR can also be used to help optimize the design of military and commercial gas turbine engines and any rotating machinery that experiences significant fluid/structure interactions.