Fluid/Structural Interaction Tools for Liquid Rocket Engines

ABSTRACT: Liquid rocket engine (LRE) turbopumps operate in complex 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 for the product design cycle. 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, with focus on LRE turbopump inducer flows. The specific technical objective of the two-year Phase II effort will be to perform a set of software development, engineering, and validation/verification tasks that answers key questions related to computational simulation of hydrodynamic damping in an LRE inducer. BENEFIT: Next-generation launch programs will require propulsion systems that deliver high thrust-to-weight ratios, increased trajectory-averages 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.