Prediction and Measurement of the Soot Build-Up in Film-Cooled Rocket Engines

ABSTRACT: Methodology for prediction of soot build-up in liquid film-cooled rocket engines will be incorporated into the CRUNCH CFD code, using a reduced-mechanism pyrolysis model and soot formation model developed at University of Virginia. A companion experimental program will be conducted at University of Virginia to collect data for calibration of the pyrolysis models for conditions and fuels of interest to liquid rocket engine design. The resulting capability in CRUNCH CFD will permit simulation of liquid fuel injection, film cooling and vaporization, fuel pyrolysis, soot formation, transport, and deposition on combustor walls, as part of complete combustor calculations, which CRUNCH CFD is currently capable of for both sub and super-critical applications. A demonstration calculation of the end-to-end framework, from liquid film formation to carbon build-up will be performed in Phase I. Proof-of-concept experiments will demonstrate the capability to collect data for calibration of the fuel pyrolysis and soot formation models , and characterize the carbon deposit. A Phase II effort will provide comprehensive data collection and model calibration, resulting in a state-of-the-art production CFD capability for prediction of soot formation and carbon build-up in liquid rocket engines.; BENEFIT: At the completion of Phase II, a validated soot pyrolsysis/formation model will be implemented in our commercial CRUNCH CFD code, providing a state-of-the-art production CFD soot modeling capability for liquid rocket engine analysis beyond other products currently available in the public domain. The commercial market for CRUNCH CFD enhanced with the soot pyrolysis/formation models resulting from the proposed effort can extend from liquid-rocket manufacturers, to gas-turbine and diesel/gas engine manufactures, where soot formation and carbon deposits can effect engine performance and pollutant release to the environment. This is a very large and diverse market and includes commercial launchers, jet engines, gas-turbines used for power generation, marine engines, railroad engines, trucks and automobiles, as well as heavy industrial engines. It is envisioned that the technology developed can be implemented into self-contained software modules which can be linked into government research codes and marketed to other commercial software suppliers.