scholarly journals Optimal regular reflection of shock and blast waves

2018 ◽  
Vol 245 ◽  
pp. 12005 ◽  
Author(s):  
Mihail Chernyshov ◽  
Alexandr Tyapko
Keyword(s):  
Gas Flow ◽  
Static Pressure ◽  
Blast Waves ◽  
Regular Reflection ◽  
Reflection Point ◽  
Equivalent Problem ◽  
Supersonic Gas Flow ◽  
Inclined Surface ◽  
Steady Shock ◽  
Extremum Conditions

The regular reflection of an oblique steady shock in supersonic gas flow is considered. The static pressure extremum conditions after the point of reflection of the shock with fixed strength depending on oncoming flow Mach number are determined analytically. The obtained results are applied to solution of the mechanically equivalent problem of the reflection of a propagating shock from an inclined surface. Non-monotonic variation of the mechanical loads on the obstacle with respect to its inclination angle is shown; the obstacle slope angles that correspond to pressure minima downwards of the unsteady shock reflection point are determined analytically.

TO THE THEORY OF UNSTEADY SEPARATION AND INTERACTION OF BOUNDARY LAYER WITH SUPERSONIC GAS FLOW

2018 ◽  
Vol 49 (4) ◽  
pp. 415-427
Author(s):  
Igor Ivanovich Lipatov ◽  
Vladimir Yakovlevich Neiland
Keyword(s):  
Boundary Layer ◽  
Gas Flow ◽  
Unsteady Separation ◽  
Supersonic Gas Flow

scholarly journals Vertical Structure of Spiral Shocks in a Corrugated Galactic Disc

1983 ◽  
Vol 100 ◽  
pp. 145-146
Author(s):  
A. H. Nelson ◽  
T. Matsuda ◽  
T. Johns
Keyword(s):  
Density Profile ◽  
Vertical Velocity ◽  
Gas Flow ◽  
Vertical Structure ◽  
Vertical Motion ◽  
Shock Structure ◽  
Galactic Disc ◽  
Gaussian Density ◽  
Abundant Evidence ◽  
Steady Shock

Numerical calculations of spiral shocks in the gas discs of galaxies (1,2,3) usually assume that the disc is flat, i.e. the gas motion is purely horizontal. However there is abundant evidence that the discs of galaxies are warped and corrugated (4,5,6) and it is therefore of interest to consider the effect of the consequent vertical motion on the structure of spiral shocks. If one uses the tightly wound spiral approximation to calculate the gas flow in a vertical cut around a circular orbit (i.e the ⊝ -z plane, see Nelson & Matsuda (7) for details), then for a gas disc with Gaussian density profile in the z-direction and initially zero vertical velocity a doubly periodic spiral potential modulation produces the steady shock structure shown in Fig. 1. The shock structure is independent of z, and only a very small vertical motion appears with anti-symmetry about the mid-plane.

Supersonic gas flow

1954 ◽  
Vol 5 (1) ◽  
pp. 1-6
Author(s):  
W A Mair
Keyword(s):  
Gas Flow ◽  
Supersonic Gas Flow

Experimental Inverstigations On the Pressure Fluctuations in the Sealing Gap of Dry Gas Seals with Embedded Pressure Sensors

2021 ◽  
Author(s):  
Jingjing Luo ◽  
Dieter Brillert
Keyword(s):  
High Speed ◽  
Gas Flow ◽  
Static Pressure ◽  
Pressure Sensors ◽  
Operating Conditions ◽  
Test Facility ◽  
Experimental Investigations ◽  
Mechanical Seals ◽  
Process Gas ◽  
Sealing Gap

Abstract Dry gas lubricated non-contacting mechanical seals (DGS), most commonly found in centrifugal compressors, prevent the process gas flow into the atmosphere. Especially when high speed is combined with high pressure, DGS is the preferred choice over other sealing alternatives. In order to investigate the flow field in the sealing gap and to facilitate the numerical prediction of the seal performance, a dedicated test facility is developed to carry out the measurement of key parameters in the gas film. Gas in the sealing film varies according to the seal inlet pressure, and the thickness of gas film depends on this fluctuated pressure. In this paper, the test facility, measurement methods and the first results of static pressure measurements in the sealing gap of the DGS obtained in the described test facility are presented. An industry DGS with three-dimensional grooves on the surface of the rotating ring, where experimental investigations take place, is used. The static pressure in the gas film is measured, up to 20 bar and 8,100 rpm, by several high frequency ultraminiature pressure transducers embedded into the stationary ring. The experimental results are discussed and compared with the numerical model programmed in MATLAB, the characteristic and magnitude of which have a good agreement with the numerical simulations. It suggests the feasibility of measuring pressure profiles of the standard industry DGS under pressurized dynamic operating conditions without altering the key components of the seal and thereby affecting the seal performance.

A Full Scale Test for Acoustic Fatigue in Pipework

2006 ◽  
Author(s):  
H. G. D. Goyder ◽  
K. Armstrong ◽  
L. Billingham ◽  
M. J. Every ◽  
T. P. Jee ◽  
...  
Keyword(s):  
Gas Flow ◽  
Static Pressure ◽  
Natural Frequencies ◽  
Full Scale ◽  
Oil Field ◽  
Structural Damping ◽  
Full Scale Test ◽  
Scale Test ◽  
Flow Through ◽  
Acoustic Fatigue

Gas flow through a corrugated pipe can produce unacceptable levels of noise. The occurrence of such noise gave rise to concerns about vibration induced fatigue of small-bore subsea pipework in the Schiehallion oil field. In order to check that the subsea pipework was free from noise-induced vibration a full scale replica of the subsea equipment containing the small-bore pipework was built and tested. The test required the generation of acoustic pressures with a 1 bar amplitude and a frequency range of 80 to 800Hz. It was also necessary to arrange for resonant conditions within the pipework and for acoustic nodes and anti-nodes to be swept though a range of possible locations. The test was conducted with full-scale conditions of methane at a static pressure of 170bar and with a range of gas flow rates. Particular attention was given to achieving the correct acoustic and structural natural frequencies together with the correct acoustic and structural damping ratios. The subsea equipment was found to be vulnerable for one operating condition. This vulnerability was removed by retro-fitting a brace to the existing subsea pipework.

Results of the Study Rotor Wheels Supersonic Microturbines with a Large Angle of Rotation of the Flow

2015 ◽  
Vol 752-753 ◽  
pp. 884-889 ◽  
Author(s):  
Andrey Yu. Fershalov ◽  
Mikhail Yu. Fershalov ◽  
Yuriy Ya. Fershalov ◽  
Timofey V. Sazonov
Keyword(s):  
Mach Number ◽  
Gas Flow ◽  
Large Angle ◽  
Experimental Investigations ◽  
Flow Rates ◽  
Ratio Speed ◽  
Supersonic Gas Flow ◽  
Angle Of Rotation

The article presents the results of experimental investigations of rotor wheels supersonic microturbines with a large angle of rotation of the flow. The characteristics of the studied rotor wheels. The analysis of the results of the study ratio speed of rotor wheels, depending on the Mach number. Recommendations for the design working wheels microturbines operating at high supersonic gas flow rates.

Plasma aerodynamics in a supersonic gas flow

2010 ◽  
Vol 48 (6) ◽  
pp. 903-909 ◽  
Author(s):  
V. V. Golub ◽  
A. S. Saveliev ◽  
V. A. Sechenov ◽  
E. E. Son ◽  
D. V. Tereshonok
Keyword(s):  
Gas Flow ◽  
Supersonic Gas Flow ◽  
Plasma Aerodynamics

Fluctuations in cavities in a supersonic gas flow

1990 ◽  
Vol 25 (2) ◽  
pp. 266-272 ◽  
Author(s):  
N. L. Zaugol'nikov ◽  
M. A. Koval' ◽  
A. I. Shvets
Keyword(s):  
Gas Flow ◽  
Supersonic Gas Flow
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