This chapter includes the effect of turbulence on combustion, a description of fuel candidates for SCRJ engines, and a brief analysis of fuels and emissions generated by the combustion of hydrogen and hydrocarbons with air at temperatures typical of SCRJ combustors. The effect of vorticity on flame holding devices is analyzed in terms of characteristic mixing and chemical kinetics times, and an analytical criterium is developed to meet the requirement to keep the combustor length short. This criterion is based on the time to dissipate turbulent kinetic energy down to fine scales and the residence time in the combustor. Next, the effect of compressibility on the low supersonic Mach number in the combustor and that on chemical kinetics are discussed separately. Preliminary sizing is assessed using the criterion just developed and semi-empirical information. Physical modeling of the combustion process is proposed based on the Crocco–Vaszonyi equation to derive the turbulent kinetic energy source at fine scales. Candidate fuels for SCRJ engines are discussed that include hydrogen, conventional hydrocarbons and endothermic fuels, the choice assessed in terms of density, cooling capability, and logistics. Finally, information on emissions from hydrogen-fueled SCRJ engines are reported from past work in this area for an EU project.
Combustion
sp propuls
2023-11-28
48 pages
Article/Chapter (Book)
Electronic Resource
English
NTRS | 1971
|NTRS | 1966
|Engineering Index Backfile | 1940
|Engineering Index Backfile | 1939
|Combustion Indexes for Innovative Combustion Control
SAE Technical Papers | 2017
|