Experimental and theoretical study of shock wave propagation through double-bend ducts

2001 ◽  
Vol 437 ◽  
pp. 255-282 ◽  
Author(s):  
O. IGRA ◽  
X. WU ◽  
J. FALCOVITZ ◽  
T. MEGURO ◽  
K. TAKAYAMA ◽  
...  

The complex flow and wave pattern following an initially planar shock wave transmitted through a double-bend duct is studied experimentally and theoretically/numerically. Several different double-bend duct geometries are investigated in order to assess their effects on the accompanying flow and shock wave attenuation while passing through these ducts. The effect of the duct wall roughness on the shock wave attenuation is also studied. The main flow diagnostic used in the experimental part is either an interferometric study or alternating shadow–schlieren diagnostics. The photos obtained provide a detailed description of the flow evolution inside the ducts investigated. Pressure measurements were also taken in some of the experiments. In the theoretical/numerical part the conservation equations for an inviscid, perfect gas were solved numerically. It is shown that the proposed physical model (Euler equations), which is solved by using the second-order-accurate, high-resolution GRP (generalized Riemann problem) scheme, can simulate such a complex, time-dependent process very accurately. Specifically, all wave patterns are numerically simulated throughout the entire interaction process. Excellent agreement is found between the numerical simulation and the experimental results. The efficiency of a double-bend duct in providing a shock wave attenuation is clearly demonstrated.

1996 ◽  
Vol 313 ◽  
pp. 105-130 ◽  
Author(s):  
O. Igra ◽  
J. Falcovitz ◽  
H. Reichenbach ◽  
W. Heilig

The interaction of a planar shock wave with a square cavity is studied experimentally and numerically. It is shown that such a complex, time-dependent, process can be modelled in a relatively simple manner. The proposed physical model is the Euler equations which are solved numerically, using the second-order-accurate high-resolution GRP scheme, resulting in very good agreement with experimentally obtained findings. Specifically, the wave pattern is numerically simulated throughout the entire interaction process. Excellent agreement is found between the experimentally obtained shadowgraphs and numerical simulations of the various flow discontinuities inside and around the cavity at all times. As could be expected, it is confirmed that the highest pressure acts on the cavity wall which experiences a head-on collision with the incident shock wave while the lowest pressures are encountered on the wall along which the incident shock wave diffracts. The proposed physical model and the numerical simulation used in the present work can be employed in solving shock wave interactions with other complex boundaries.


2016 ◽  
Vol 57 (8) ◽  
Author(s):  
V. Rodriguez ◽  
G. Jourdan ◽  
A. Marty ◽  
A. Allou ◽  
J.-D. Parisse

1977 ◽  
Author(s):  
Charles Kingery ◽  
Richard Pearson ◽  
George Coulter

Author(s):  
Alexander Ivanov ◽  
Nicolas Fassardi ◽  
Christina Scafidi ◽  
Tal Shemen ◽  
Veronica Eliasson

Energies ◽  
2018 ◽  
Vol 11 (12) ◽  
pp. 3275
Author(s):  
Chenyuan Liu ◽  
Huoxing Liu

Leakage flow between the rotor and the stator can cause serious performance degradation of wave rotors which utilize nonsteady shock waves to directly transfer energy from burned gases to precompressed air. To solve this problem, primary flow features relevant to leakage are extracted and it was found that the leakage-attributed performance degradation could be abstracted to a special initial-boundary value problem of one-dimensional Euler equations. Then, a general loss assessment method is proposed to solve the problem of nonsteady flow loss prediction. Using the above method, a reasonable physical hypothesis of the initial-boundary value problem depicting the nonsteady leakage flow process is proposed and further, a closed-form leakage loss analytical model combined with an empirical correction method for the discharge coefficient is established. Finally, with the experimentally verified CFD method, comprehensive numerical verification is conducted for the loss prediction model; it is proved that the physical hypothesis of the proposed model in this paper is reasonable and the model is capable of predicting nonsteady shock wave attenuation due to leakage exactly within the range of parameter variations of wave rotors.


Sign in / Sign up

Export Citation Format

Share Document