Measurement and Modeling of Surface Coking in Fuel-Film Cooled Liquid Rocket Engines

Designing an efficient and effective film cooling system to protect critical components of modern rocket engines requires a significant number of problems and challenges to be addressed. Complicating the already difficult hydrodynamic challenges, thermal and/or catalytic cracking of hydrocarbon fuels is always accompanied with coke formation. Coke deposits on combustor and nozzle walls reduce heat fluxes and can have unwanted effects on regenerative heating of the fuel flowing through the outer channels. The overall goal of this project is to develop and validate models for surface coking under conditions relevant to fuel film cooled liquid rocket engines. In Phase I, the team of CFDRC Purdue University and Dr. Hai Wang demonstrated feasibility of developing such models. Phase II plans include a) complete the development and implementation of predictive coke deposition models, b) conduct target experiments to isolate effects of different aspects of coke deposition and to provide improved understanding of coke formation, c) validate and calibrate coke deposition models against test data, d) quantify measurement and prediction uncertainties and identify error bounds associated with heat transfer prediction, and e) develop APIs to integrate developed models with 3-D CFD codes used by the Air Force for liquid rocket engine analysis.