Vaporization and Zonal Mixing in Performance Modeling of Advanced LOX-Methane Rockets
Initial modeling of LOX-Methane reaction control (RCE) 100 lbf thrusters and larger, 5500 lbf thrusters with the TDK/VIPER code has shown good agreement with sea-level and altitude test data. However, the vaporization and zonal mixing upstream of the compressible flow stage of the models leveraged empirical trends to match the sea-level data. This was necessary in part because the codes are designed primarily to handle the compressible part of the flow (i.e. contraction through expansion) and in part because there was limited data on the thrusters themselves on which to base a rigorous model. A more rigorous model has been developed which includes detailed vaporization trends based on element type and geometry, radial variations in mixture ratio within each of the “zones” associated with elements and not just between zones of different element types, and, to the extent possible, updated kinetic rates. The Spray Combustion Analysis Program (SCAP) was leveraged to support assumptions in the vaporization trends. Data of both thrusters is revisited and the model maintains a good predictive capability while addressing some of the major limitations of the previous version.
Practical uses of liquid methane in rocket engine applications
Abstract Liquid methane has been considered an attractive rocket propellant for several decades. However, most rocket engine development efforts in the last 30 years have focused on using more traditional fuels such as hydrogen, kerosene, and earth storables, without any serious development or application of methane to propulsion systems. This paper presents a summary of recent 870 lbf thrust LOX / LCH 4 (liquid oxygen/liquid methane) engine test results and recent LOX / LCH 4 torch igniter testing. Multiple test series were conducted using both radiation cooled and ablative chamber hardware. This engine testing yielded measured minimum C * efficiencies of 97% using non-optimized engine hardware, with expectations that better than 99% efficiency can readily be achieved with minor hardware optimization. The combustion process was shown to be stable in all tests and the operating transition from poor quality methane (two-phase fluid) at startup to liquid–liquid, sub-cooled, steady state operation was demonstrated. Engine test results showed chamber wall compatibility with high propellant mixture ratios and excellent boundary layer performance of methane as a chamber film coolant. The Aerojet work on methane propulsion and energy applications is also briefly summarized.
The mark of sexual preference in the interpretation of texts: preface to a homosexual reading.
Since reading is an interaction or confrontation between the reader and the text-an interaction that depends upon the background and perspectives of the reader as well as on the text being read-we can assume that the dynamics of sexuality and sexual object choice will influence how readers ascribe meaning to literary texts. In fact, although other aspects of our identities come into play when we read, sexual identity is unique and central because of the role that it plays in the creation of subjectivity. Specifically, male homosexuality informs and structures the reading of texts. But what does it be a homosexual reader or to effectuate a homosexual reading of a particular text?