[PDF] Top 20 Turbulent Combustion Closure Modeling for High Speed LES.

... scramjet combustion; these high speed reactive flows are characterized by the coupling of several different complex physical ...when combustion occurs as well as significant compressibility ... See full document

... a high number of photons is needed. This number can be fairly high for establishing an externally determined set of random numbers that will need to be stored and would require a prohibitive amount of ... See full document

... subgrid closure models tested in the present chapter generally decrease the magnitude of the species production rates, relative to the ‘laminar chemistry’ ...modeled turbulent mixing near the grid ... See full document

... necessary high fidelity, they impose strict spatial resolution constraints that lead to a very high computational ...additional modeling, which in turn introduces further numerical ...implicit ... See full document

... Computational fluid dynamics uses the flow governing equations which are continuity equation, momentum equations, energy equation and the equation of state. They govern any Newtonian fluid flow field; whether laminar or ... See full document

... discussions, the general conclusions essentially reaffirm basic theories concerning these indicators. Scalar dissipation tends to be highest in regions where the velocity and scalar gradients are largest, and ... See full document

... constant turbulent Schmidt ...supersonic combustion processes are extremely sentitive to small changes in the turbulent Schmidt ...the turbulent Schmidt ...hydrogen-air combustion ... See full document

... for combustion are: high auto-ignition ...efficiencies; high diffusivity. More homogenous combustion due to more uniform air-fuel mixture and will disperse quickly if leaking; wide range of ... See full document

... of LES v1, which had the air-throttle setting at 25 gm/s, causing aerodynamic choking of the flow to move the shock train further ...upstream. LES v1 also has a larger peak pressure than LES v4 in ... See full document

... the speed of the train is nearly stable during the ...that modeling HSR link quality with HMC is suitable for specific situations where these two preconditions are ... See full document

... and closure of the high-level waste (HLW) tanks that currently store millions of gallons of highly radioactive ...to closure. After closure the impact of carbonation (and concurrent oxidation) ... See full document

... pressure-induced eddies in the logarithmic region of the boundary layer. Its scaling behaviour was predicted by Bradshaw [3], and was verified theoretically [56] and experimentally [8, 6]. This frequency region can be ... See full document

... SI combustion to HCCI mode and to increase the load capacity of the HCCI ...various speed and load combinations, were used to study the response of the ...the combustion timing to vary ...to ... See full document

... a combustion chamber is often used in medium- and large-sized engines with various forms, such as water-emulsified fuel injection, stratified fuel-water injection (SFWI) [6] and in- dependent water ...worsen ... See full document

... not high so air can be considered uncompressible, the airflow speed at the outlet cross-section increases as the inlet airflow speed ...inlet speed with an improper angle may cause a ... See full document

... the turbulent spectrum, with an effective rms at the flame front of u k [3], with u k  u  found from integration of the turbulent power spectral density function between the limiting wave numbers ... See full document

... flame remained stable at the base but blew off in the downstream neck region of the burner. Improvements in blow-off limits occurred when the swirl number reaches a certain threshold of about 0.6. Similar conclusions ... See full document

... THE PROBLEM AND Tl-IE OBJECT OF THE INVESTIGATION At the present time ignition by high tension electric spark is almost universal on high speed reciprocating internal combustion engines [r] ... See full document

... The simulation of this experiment is shown in Fig. 7. In this calculation, at time t = 10.0 mcs, as in the experiment, material is ejected from the back of the sample. The destruction of the drummer into fragments under ... See full document

... With these assumptions and by applying the combustion model for laminar flow, the computed values of several product species fractions were corrected. This approach is based on the assump­ tion that variables ... See full document