Backward uncertainty propagation method in flow problems: Application to the prediction of rarefaction shock waves

2012 ◽  
Vol 213-216 ◽  
pp. 314-326 ◽  
Author(s):  
P.M. Congedo ◽  
P. Colonna ◽  
C. Corre ◽  
J.A.S. Witteveen ◽  
G. Iaccarino
Keyword(s):  
Shock Waves ◽  
Uncertainty Propagation ◽  
Flow Problems ◽  
Rarefaction Shock

Negative shock waves

1973 ◽  
Vol 60 (1) ◽  
pp. 187-208 ◽  
Author(s):  
P. A. Thompson ◽  
K. C. Lambrakis
Keyword(s):  
Shock Waves ◽  
Continuum Model ◽  
Single Phase ◽  
Thermodynamic Quantity ◽  
Stability Conditions ◽  
Formation And Evolution ◽  
Molecular Complexity ◽  
Rarefaction Shock ◽  
Dynamic Formation ◽  
Negative Shock

Negative or rarefaction shock waves may exist in single-phase fluids under certain conditions. It is necessary that a particular fluid thermodynamic quantity Γ ≡ −½δ In (δP/δν)s/δ In ν be negative: this condition appears to be met for sufficiently large specific heat, corresponding to a sufficient level of molecular complexity. The dynamic formation and evolution of a negative shock is treated, as well as its properties. Such shocks satisfy stability conditions and have a positive, though small, entropy jump. The viscous shock structure is found from an approximate continuum model. Possible experimental difficulties in the laboratory production of negative shocks are briefly discussed.

The admissibility domain of rarefaction shock waves in the near-critical vapour–liquid equilibrium region of pure typical fluids

2016 ◽  
Vol 795 ◽  
pp. 241-261 ◽  
Author(s):  
Nawin R. Nannan ◽  
Corrado Sirianni ◽  
Tiemo Mathijssen ◽  
Alberto Guardone ◽  
Piero Colonna
Keyword(s):  
Shock Waves ◽  
Critical Point ◽  
Compressible Flows ◽  
Three Dimensional ◽  
Fundamental Equation ◽  
Phase Region ◽  
Liquid Equilibrium ◽  
Two Phase ◽  
Rarefaction Shock ◽  
Equilibrium Region

Application of the scaled fundamental equation of state of Balfour et al. (Phys. Lett. A, vol. 65, 1978, pp. 223–225) based upon universal critical exponents, demonstrates that there exists a bounded thermodynamic domain, located within the vapour–liquid equilibrium region and close to the critical point, featuring so-called negative nonlinearity. As a consequence, rarefaction shock waves with phase transition are physically admissible in a limited two-phase region in the close proximity of the liquid–vapour critical point. The boundaries of the admissibility region of rarefaction shock waves are identified from first-principle conservation laws governing compressible flows, complemented with the scaled fundamental equations. The exemplary substances considered here are methane, ethylene and carbon dioxide. Nonetheless, the results are arguably valid in the near-critical state of any common fluid, namely any fluid whose molecular interactions are governed by short-range forces conforming to three-dimensional Ising-like systems, including, e.g. water. Computed results yield experimentally feasible admissible rarefaction shock waves generating a drop in pressure from 1 to 6 bar and pre-shock Mach numbers exceeding 1.5.

A Switch Function-Based Gas-Kinetic Scheme for Simulation of Inviscid and Viscous Compressible Flows

2016 ◽  
Vol 8 (5) ◽  
pp. 703-721 ◽  
Author(s):  
Yu Sun ◽  
Chang Shu ◽  
Liming Yang ◽  
C. J. Teo
Keyword(s):  
Shock Waves ◽  
Compressible Flows ◽  
Stokes Equations ◽  
Mach Reflection ◽  
Strong Shock ◽  
Kinetic Scheme ◽  
Numerical Dissipation ◽  
Flow Problems ◽  
Viscous Compressible Flows ◽  
Strong Shock Waves

AbstractIn this paper, a switch function-based gas-kinetic scheme (SF-GKS) is presented for the simulation of inviscid and viscous compressible flows. With the finite volume discretization, Euler and Navier-Stokes equations are solved and the SF-GKS is applied to evaluate the inviscid flux at cell interface. The viscous flux is obtained by the conventional smooth function approximation. Unlike the traditional gas-kinetic scheme in the calculation of inviscid flux such as Kinetic Flux Vector Splitting (KFVS), the numerical dissipation is controlled with a switch function in the present scheme. That is, the numerical dissipation is only introduced in the region around strong shock waves. As a consequence, the present SF-GKS can well capture strong shock waves and thin boundary layers simultaneously. The present SF-GKS is firstly validated by its application to the inviscid flow problems, including 1-D Euler shock tube, regular shock reflection and double Mach reflection. Then, SF-GKS is extended to solve viscous transonic and hypersonic flow problems. Good agreement between the present results and those in the literature verifies the accuracy and robustness of SF-GKS.

Paper 14: Numerical Solutions of Flows behind Shock Waves in Non-Uniform Regions

1969 ◽  
Vol 184 (7) ◽  
pp. 36-44
Author(s):  
J. Gururaja ◽  
B. E. L. Deckker
Keyword(s):  
Shock Waves ◽  
High Speed ◽  
Numerical Solutions ◽  
Computing Time ◽  
Sudden Change ◽  
Two Dimensional ◽  
Cell Method ◽  
Flow Problems ◽  
Pressure Time ◽  
Machine Calculation

Different computational schemes for the calculation of multi-dimensional non-stationary problems of gas dynamics with shock waves present are reviewed. A differencing scheme developed in the last few years at the Los Alamos Scientific Laboratory, known as the ‘fluid-in-cell’ method, has been employed to obtain numerical solutions for the time-dependent two-dimensional flows initiated by the passage of a shock wave in a duct with either a gradual or sudden change in cross-section and in a branched duct. The numerical results have been displayed in the form of contours of density, pressure, and internal energy. The main features of the computed solutions have been compared with the experimental flow patterns obtained by the authors. Comparison of pressure–time records shows good agreement. The fluid-in-cell method is well suited for machine calculation on a high-speed electronic computer and can treat unsteady two-dimensional compressible flow problems involving a single material within closed boundaries, without excessive demands on storage and computing time.

Rarefaction shock waves in iron from explosive loading

1986 ◽  
Vol 22 (3) ◽  
pp. 343-350 ◽  
Author(s):  
A. G. Ivanov ◽  
S. A. Novikov
Keyword(s):  
Shock Waves ◽  
Explosive Loading ◽  
Rarefaction Shock
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