The Dependence of Carbon Deposition on Propane Concentration from Flowing Hot, High-Pressure Methane/Propane Mixtures Through an Asymmetrically Heated Tube: TOR-2021-02036
[Technical Report, Technical Report]
The Aerospace Corporation
Pagination or Media Count:
An experimental study was conducted to investigate the dependence of carbon deposition on propane concentration for supercritical methanepropane mixtures flowed through an asymmetrically heated stainless-steel tubular test section at about 3300 psi. Propane concentrations nominally ranged from 0 to 25 by mole. One side of the test section was in contact with a copper block heated to roughly 740oC the other side rested on a near-adiabatic ceramic support. After each test run, the test section was cut into segments, split open, and analyzed with SEMEDS to examine for carbon deposits. Various levels of carbon deposition were seen, even for cases with no propane i.e., pure methane. Several forms of carbon deposition were observed. The extent of the surface that was covered with carbon and the form of the carbon deposits did not correlate significantly with propane concentration over the range tested. The surface morphology of the interior surfaces of the test sections varied from tube to tube although this appeared to have a minor effect on the extent of carbon coverage, it was not examined in a controlled manner for this study. Under some conditions, the amount of carbon deposition was significant. Although the test conditions are not directly representative of a particular rocket engine cooling channel, there are potentially important implications for systems intended for longrepeated duty cycles or multi-mission reuse.