Kinetics simulations of high pressure CH

Rocco Carmine Pellegrini, Claudio Bruno, Eugenio Giacomazzi

Research output: Contribution to conferencePaper

Abstract

The use of hydrocarbon propellants with liquid oxygen for future propulsion reusable booster or LRE seems very attractive. These propellants show reasonably good performance at low cost, while their high density will reduce overall stage dimensions and dry launcher mass. Moreover, they are non-toxic and storable at moderate cryo-cooling cost. In Europe, the suitable candidate fuels considered for this purpose are methane and kerosene. Methane especially shows many important features (highest performance, better cooling capabilities, higher cracking limit). The aim of this work is to acquire a greater understanding of the chemical kinetics of high pressure combustion processes using a methaneoxygen propellant combination. In order to do that we have acquired a large amount of data concerning laminar premixed flame velocity and ignition delay time. These data are the results of numerical simulation carried on in the ENEA Thermo-fluid Dynamics Laboratory using the CHEMKIN III numerical code. In particular, we used the Senkin application to compute ignition delay time and Premix to predict laminar flame speed. We have used the chemical reaction mechanism GRI-Mech 3.0 performing simulations in the pressure range 1 to 150 atm. The inlet temperature was varied from 300 K to 1400 K; we have also investigated an equivalence ratio from 0.1 to 6. Finally, we have performed comparisons substituting part of the methane with methanol. In this way, we wanted to test the potential of methanol to speed up methane combustion process. Some of the results are presented below. We have shown the behaviour of ignition delay time as a function of temperature founding an inverse logarithmic dependence, as expected from theory. The ignition delay time decreases with increasing pressure, tending to an almost asymptotic value. The behaviour of laminar flame speed as a function of temperature indicates that the dependence of flame speed from temperature (at constant pressure) is well represented by a quadratic polynomial (aT2+bT+c). Laminar flame speed decreases as pressure increases as expected from theoretical considerations. The ignition delay times obtained are very interesting because they assure us that we would not have problems of ignition or flame anchorage. Even the values of the laminar flame speed, though decreasing with pressure, are still high enough to grant stable combustion and high mass flow rate, when projected in flame models based on flamelet theory. Finally, adding methanol to the initial mixture was also explored to effectively speed up combustion in the high temperature range. © 2003 by the American Institute of Aeronautics and Astronautics, Inc. All rights reserved.
Original languageEnglish
Publication statusPublished - 2003
Event39th AIAA/ASME/SAE/ASEE Joint Propulsion Conference and Exhibit 2003 - , United States
Duration: 1 Jan 2003 → …

Conference

Conference39th AIAA/ASME/SAE/ASEE Joint Propulsion Conference and Exhibit 2003
CountryUnited States
Period1/1/03 → …

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All Science Journal Classification (ASJC) codes

  • Aerospace Engineering
  • Control and Systems Engineering
  • Electrical and Electronic Engineering

Cite this

Pellegrini, R. C., Bruno, C., & Giacomazzi, E. (2003). Kinetics simulations of high pressure CH. Paper presented at 39th AIAA/ASME/SAE/ASEE Joint Propulsion Conference and Exhibit 2003, United States.