scholarly journals The effect of detonation wave incidence angle on the acceleration of flyers by explosives heavily laden with inert additives

2017 ◽  
Author(s):  
Jason Loiseau ◽  
William Georges ◽  
David L. Frost ◽  
Andrew J. Higgins
Keyword(s):  
Detonation Wave ◽  
Incidence Angle ◽  
Wave Incidence Angle ◽  
Wave Incidence

Influence of Plane-Wave Incidence Angle on Whole Body and Local Exposure at 2100 MHz

2011 ◽  
Vol 53 (1) ◽  
pp. 48-52 ◽  
Author(s):  
Emmanuelle Conil ◽  
Abdelhamid Hadjem ◽  
Azeddine Gati ◽  
Man-Fai Wong ◽  
Joe Wiart
Keyword(s):  
Plane Wave ◽  
Incidence Angle ◽  
Whole Body ◽  
Local Exposure ◽  
Wave Incidence Angle ◽  
Wave Incidence ◽  
Plane Wave Incidence

Further experiments on transition to Mach reflexion

1979 ◽  
Vol 94 (3) ◽  
pp. 541-559 ◽  
Author(s):  
L. F. Henderson ◽  
A. Lozzi
Keyword(s):  
Shock Wave ◽  
Incidence Angle ◽  
Real Gas ◽  
Specific Heats ◽  
Real Gas Effects ◽  
Weak Shocks ◽  
Wave Incidence Angle ◽  
Wave Incidence ◽  
Theory And Experiment ◽  
Mach Reflexion

Our 1975 paper reported the results of experiments on shock reflexion in a wind tunnel and a shock tube; further results are presented here. For strong shocks it is shown that transition to Mach reflexion takes place continuously at the shock wave incidence angle ω0 corresponding to the normal shock point ω0 = ωN, unless the downstream boundaries form a throat. In this event transition can be promoted anywhere within the range ω0 [les ] ωN, and it is even possible to suppress regular reflexion altogether! However when ω0 < ωN the transition is discontinuous and accompanied by hysteresis. Again for strong shocks evidence is presented which suggests that the famous persistence of regular reflexion beyond the ωN point ω0 > ωN is spurious. For weak shocks the transition condition is not known but it is found that even for regular reflexion a marked discrepancy between theory and experiment develops as the shocks become progressively weaker. Also when weak shocks diffract over single concave corners there is a somewhat surprising discontinuity in the regular reflexion range. It seems that none of these phenomena can be adequately explained by real gas effects such as viscosity and variation of specific heats.

scholarly journals Характер деформаций на границе раздела упругих сред при условии скольжения

2018 ◽  
Vol 44 (9) ◽  
pp. 88
Author(s):  
Н.В. Чертова ◽  
Ю.В. Гриняев
Keyword(s):  
Wave Propagation ◽  
Incidence Angle ◽  
Contact Condition ◽  
Elastic Media ◽  
Transverse Waves ◽  
Distortion Tensor ◽  
Elastic Distortion ◽  
Deformation Modes ◽  
Wave Incidence Angle ◽  
Wave Incidence

AbstractFresnel coefficients obtained when solving the problem of wave propagation through the interface of two elastic media and expressions for components of the elastic-distortion tensor allow one to study the character of dynamic deformations at the interface. Deformation modes different from zero at the interface of the elastic media under the slip-contact condition have been determined. Dependences of deformation amplitudes at the interface on the wave incidence angle and parameters of the adjacent media for incident longitudinal and transverse waves have been constructed and analyzed.

scholarly journals The EFP Formation and Penetration Capability of Double-Layer Shaped Charge with Wave Shaper

Materials ◽  
2020 ◽  
Vol 13 (20) ◽  
pp. 4519
Author(s):  
Yakun Liu ◽  
Jianping Yin ◽  
Zhijun Wang ◽  
Xuepeng Zhang ◽  
Guangjian Bi
Keyword(s):  
Detonation Wave ◽  
Double Layer ◽  
Detonation Velocity ◽  
Incidence Angle ◽  
Shaped Charge ◽  
Experimental Simulation ◽  
Detonation Waves ◽  
Forming Process ◽  
Large Length ◽  
Overdriven Detonation

Detonation waves will bypass a wave shaper and propagate in the form of a horn wave in shaped charge. Horn waves can reduce the incidence angle of a detonation wave on a liner surface and collide with each other at the charge axis to form overdriven detonation. Detection electronic components of small-caliber terminal sensitive projectile that are limited by space are often placed inside a wave shaper, which will cause the wave shaper to no longer be uniform and dense, and weaken the ability to adjust detonation waves. In this article, we design a double-layer shaped charge (DLSC) with a high-detonation-velocity explosive in the outer layer and low-detonation-velocity explosive in the inner layer. Numerical and experimental simulation are combined to compare and analyze the forming process and penetration performance of explosively formed projectile (EFP) in DLSC and ordinary shaped charge (OSC). The results show that, compared with OSC, DLSC can also adjust and optimize the shape of the detonation wave when the wave shaper performance is poor. DLSC can obtain long rod EFPs with a large length-diameter ratio, which greatly improves the penetration performance of EFP.

Inversion of P-SV seismic data

Geophysics ◽  
1986 ◽  
Vol 51 (5) ◽  
pp. 1056-1068 ◽  
Author(s):  
James J. Carazzone
Keyword(s):  
Plane Wave ◽  
Riccati Equation ◽  
Incidence Angle ◽  
Surface Velocity ◽  
Complex Frequency ◽  
Velocity Measurements ◽  
Surface Source ◽  
Matrix Riccati Equation ◽  
Wave Incidence ◽  
Plane Wave Incidence

In a layered elastic material, density, shear velocity, and compressional velocity can be found at any depth from broadband surface measurements at two distinct, nonzero, precritical values of plane‐wave incidence angle. Layer‐stripping inversion uses three‐component surface velocity measurements generated by a polarized surface source to determine subsurface properties incrementally. The surface velocity measurements initialize a first‐order, nonlinear, matrix Riccati equation (derived from the elastic wave equation) which takes advantage of an attractive fixed‐point condition in the complex frequency plane to extract subsurface mechanical impedances. Subsurface density and velocities are recovered from the inverted impedances at two or more plane‐wave incidence angles. General properties of the matrix Riccati equation in the complex frequency plane aid in incorporating bandwidth constraints. Inversion of synthetic plane wave data from a piece‐wise continuous model illustrates inversion effects when only a finite bandwidth is available and when different compressional and shear wavelength distance scales are present.

Effects of Coupled Hydrodynamic in the Performance of a DP Barge Operating Close to a FPSO

2011 ◽  
Author(s):  
Daniel P. Vieira ◽  
Edgard B. Malta ◽  
Fabiano P. Rampazzo ◽  
Joa˜o Luis B. Silva ◽  
Eduardo A. Tannuri
Keyword(s):  
Incidence Angle ◽  
Accurate Determination ◽  
Control Surface ◽  
Wave Forces ◽  
Floating Bodies ◽  
First Order ◽  
Code Standard ◽  
Wave Incidence Angle ◽  
Drift Forces

In ocean systems composed by two or more closing floating bodies, coupled hydrodynamics effects must be considered. Dynamic positioned systems (DP), for example, need an accurate determination of environmental forces to guarantee a safe operation. This work presents a numerical methodology, using the WAMIT code, to evaluate both first order motions and mean drift forces of a system composed by a DP Crane Barge operating close to a turret-moored FPSO. The first order wave forces were evaluated using the code standard method. The second order forces (or mean drift forces) were obtained using the alternative control surface method. The work discussions are centered on the effects of FPSO presence on DP Barge hydrodynamics. Two relative positions between vessels were evaluated as well as three FPSO drafts (full, intermediate and ballasted). The effects of wave incidence angle were also discussed.

scholarly journals Assessment of the Power Output of a Two-Array Clustered WEC Farm Using a BEM Solver Coupling and a Wave-Propagation Model

Energies ◽  
2018 ◽  
Vol 11 (11) ◽  
pp. 2907 ◽  
Author(s):  
Philip Balitsky ◽  
Gael Verao Fernandez ◽  
Vasiliki Stratigaki ◽  
Peter Troch
Keyword(s):  
Wave Propagation ◽  
Wave Field ◽  
Wave Energy ◽  
Power Output ◽  
Incidence Angle ◽  
Separation Distance ◽  
Propagation Model ◽  
Irregular Waves ◽  
Wave Incidence ◽  
Wave Propagation Model

One of the key challenges in designing a Wave Energy Converter (WEC) farm is geometrical layout, as WECs hydrodynamically interact with one another. WEC positioning impacts both the power output of a given wave-energy project and any potential effects on the surrounding areas. The WEC farm developer must seek to optimize WEC positioning to maximize power output while minimizing capital cost and any potential deleterious effects on the surrounding area. A number of recent studies have shown that a potential solution is placing WECs in dense arrays of several WECs with space between individual arrays for navigation. This innovative arrangement can also be used to reduce mooring and cabling costs. In this paper, we apply a novel one-way coupling method between the NEMOH BEM model and the MILDwave wave-propagation model to investigate the influence of WEC array separation distance on the power output and the surrounding wave field between two densely packed WEC arrays in a farm. An iterative method of applying the presented one-way coupling to interacting WEC arrays is used to compute the wave field in a complete WEC farm and to calculate its power output. The notion of WEC array ‘independence’ in a farm from a hydrodynamic point of view is discussed. The farm is modeled for regular and irregular waves for a number of wave periods, wave incidence angles, and various WEC array separation distances. We found strong dependency of the power output on the wave period and the wave incidence angle for regular waves at short WEC array–array separation distances. For irregular wave operational conditions, a large majority of WEC array configurations within a WEC farm were found to be hydrodynamically ‘independent’.

Electron Channeling Patterns

1977 ◽  
Vol 35 ◽  
pp. 12-13
Author(s):  
David C. Joy
Keyword(s):  
Electron Diffraction ◽  
Incidence Angle ◽  
Photographic Plate ◽  
Diffraction Effect ◽  
Angle Of Incidence ◽  
Bulk Single Crystal ◽  
Time Resolved ◽  
Electron Channeling ◽  
Spatially Resolved ◽  
Large Bulk

Electron channeling patterns (ECP) were first found by Coates (1967) while observing a large bulk, single crystal of silicon in a scanning electron microscope. The geometric pattern visible was shown to be produced as a result of the changes in the angle of incidence, between the beam and the specimen surface normal, which occur when the sample is examined at low magnification (Booker, Shaw, Whelan and Hirsch 1967).A conventional electron diffraction pattern consists of an angularly resolved intensity distribution in space which may be directly viewed on a fluorescent screen or recorded on a photographic plate. An ECP, on the other hand, is produced as the result of changes in the signal collected by a suitable electron detector as the incidence angle is varied. If an integrating detector is used, or if the beam traverses the surface at a fixed angle, then no channeling contrast will be observed. The ECP is thus a time resolved electron diffraction effect. It can therefore be related to spatially resolved diffraction phenomena by an application of the concepts of reciprocity (Cowley 1969).

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