Numerical analysis of supersonic combustion ramjet with upstream fuel injection

Abstract

SUMMARYThis paper describes possible fuel injection scheme for airbreathing engines that use hydrocarbon fuels. The basic idea is to inject fuel at the spike tip of the supersonic inlet to achieve mixing and combustion e ciency with a limited length combustion chamber. A numerical code, able to solve the full NavierStokes equations in turbulent and reacting ows, is employed to obtain numerical simulations of the thermo-uidynamic ÿelds at di erent scramjet ight conditions, at Mach numbers of M = 6:5 and 8. The feasibility of the idea of the upstream injection is checked for a simple axisymmetric conÿguration and relatively small size.The results are discussed in connection with the potential beneÿts deriving from the use of new ultra high temperature ceramics (UHTC).

Modeling of Supersonic Combustion Systems for Sustained Hypersonic Flight

“…For inlet injection specifically, a challenge is presented in ensuring that the combustion is held within the engine, thus preventing inlet unstart. Initial research into the viability of upstream injection is provided in [7], concluding that for any study optimizing the location of fuel injection in general plays a significant role in overall efficiency. It is generally understood that increased fuel jet penetration leads to greater total pressure loss; this assumption is investigated specifically for the concept design in the following section.…”

“…For inlet injection specifically, a challenge is presented in ensuring that the combustion is held within the engine, thus preventing inlet unstart. Initial research into the viability of upstream injection is provided in [7], concluding that for any study optimizing the location of fuel injection in general plays a significant role in overall efficiency. …”

Impact of parametric variation on combustion characteristics of hydrogen‐fueled strut based scramjet combustor at supersonic speed

“…Fast mixing was achieved by placing the strut at the channel axis. Possible fuel injection approach is numerically explained by Savino and Pezzella 31 . Also the mixing and combustion efficiency was achieved with the restricted length of the combustor.…”

Orbital Payload Delivery Using Hydrogen and Hydrocarbon Fuelled Scramjet Engines

“…Hydrocarbons have up to 11 times the storage density of hydrogen [7] making the tanks and therefore the entire vehicle much smaller compared with an equivalent propellant mass hydrogen powered vehicle. Hydrogen does however have a significantly higher specific impulse [3], [5]. In addition, hydrogen is the only fuel likely to deliver net positive levels of thrust at near orbital velocities [7].…”

“…A number of fuel types have been investigated in the literature for use in scramjet propulsion systems, from solid [4] and liquid [5] hydrocarbon based fuels to various phases of hydrogen [6]. Hydrocarbon fuels have a distinct advantage over hydrogen with respect to storage.…”