Modeling of Hypersonic Flows: Influence of the Starting Conditions of the Algorithm on the Final Solution in the Vicinity of Bifurcation Points

Shock-wave modes of flow at the inlet to the diffuser of a hypersonic scramjet engine: The effect of flight altitude and velocity

“…Note that this technique is widely used in solving problems in classical aerodynamics (assuming the invariability of the properties of gas medium); however, some of its aspects exhibit special features in the case of abrupt variation of these properties on an SW (see [21]). Note that this technique is widely used in solving problems in classical aerodynamics (assuming the invariability of the properties of gas medium); however, some of its aspects exhibit special features in the case of abrupt variation of these properties on an SW (see [21]).…”

“…The concrete form of dependence (1) and detailed analysis of SP in the case of variation of γ + , γ -, and Mare given in [20,21]. It is restricted by the values of θ min ≤ θ ≤ θ max and ξ min ≤ ξ ≤ ξ max and is mirror-symmetric relative to the straight line θ s = 0.5(θ min + θ max ).…”

“…According to the physics of the process, the former case is realized more frequently: additional degrees of freedom (for example, vibrational) are excited behind the shock, and the value of γ decreases (falling regions of curves in Fig. A detailed description of the model of effective adiabatic exponent, the range of its validity, gasdynamic relations, and the difference from the classical model are given in [18][19][20], and the effect of γ i on the form of SP is investigated in [21]. The latter case is the region of parameters before and behind the shock front, located in the rising regions of curves in Fig.…”

“…However, this range is of interest and was selected for investigation largely for the following two reasons. 2 in which the shock-wave transition occurs (for more detail, see [21]). In addition, in their analysis, the results given below allow a certain degree of interpolation and, with some caution, extrapolation with respect to parameters.…”

Changes in the type of the shock-wave structure in high-velocity flows

“…The effective ratio of specific heats γ reflects the physics of the process: its value equals 5/3 for a monatomic gas in the free stream, decreases because of excitation of electron shells, and increases owing to ionization. Note, an analysis of processes from this viewpoint in a number of problems of dynamics of a reacting gas [10][11][12][13] with γ reduced to 1.22 in argon and to 1.06 in alcohol vapors made it possible to explain some phenomena anomalous from the viewpoint of the classical gas dynamics, such as instability and breakdown of the bow shock wave in a hypersonic flow around a blunted body. Figure 2 shows the polars of two incident (i 1 and i 2 ) and two reflected (r 1 and r 2 ) shock waves.…”