Computational Modeling of Supercritical and Transcritical Flows

Transcritical diffuse-interface hydrodynamics of propellants in high-pressure combustors of chemical propulsion systems

“…Although there may be several definitions of the character of transcritical conditions in the literature [1][2][3][4]6,7,[9][10][11][12][13][14]19,22,24,25,30,32,33,[35][36][37], one that is of practical relevance for chemical propulsion systems corresponds to the thermodynamic conditions attained in the injection configuration sketched in Fig. 1.…”

“…In particular, Eq. ( 35) connects the oscillation amplitude A μ , which can be obtained independently from the thermodynamic relations ( 14) and (30), with the intrinsic properties of the interface δ I and σ 0 , the latter being a measurable quantity. A cornerstone of the diffuse-interface theory is that the order of magnitude of κ is set such that δ I estimated from (34) is small enough to yield values of σ 0 from Eq.…”

“…The characteristic amplitude of the pressure oscillation within the interface, denoted by A P , is obtained from Eqs. ( 29), (30), and ( 35) giving Eq. ( 36) yields A P ∼ 10-100 bar when the estimates for σ 0 and δ I introduced above are employed.…”

“…The high pressures, however, limit the amount of information that can be obtained from state-of-the-art experimental diagnostics. Numerical simulations have accompanied these endeavors [24][25][26][27][28][29][30][31], but most of these computations have been limited to high-pressure conditions that did not warrant the existence of interfaces. Major reviews in the field have also focused on those conditions [32][33][34].…”