Finite-difference modelling of pulse-echo scattering using a water-coupled transducer

Stacey, Richard
May 2000
AIP Conference Proceedings;2000, Vol. 509 Issue 1, p113
Academic Journal
We report the development of new techniques for modeling pulse-echo scattering using a water-coupled transducer, and their success in accurately predicting both the size and shape of the echoes from small solid defects. Our new methods use separate grids to model the solid and the liquid, and these are only related along the interface using pseudonode formulations based on the boundary conditions. The twin grid formulation does not have any problems with discontinuities along the interface. It has also been shown to have excellent stability properties. When we compare our finite difference predictions with experimental data from known defects, we take care to subtract measurements made without the defect (with all else unchanged) from the measurements with the defect, in order to avoid spurious interface echoes. We do this for both the experimental and the finite-difference “data.” The finite difference predictions match the experimental measurements to high accuracy. Having validated the finite difference techniques, we can use them to monitor and visualize the various scattered and reflected waves, giving valuable insights into their physical origins. © 2000 American Institute of Physics.


Related Articles

  • Shear cell for the study of liquid-solid interfaces by neutron scattering. Baker, Shenda M.; Smith, Gregory; Pynn, Roger; Butler, Paul; Hayter, John; Hamilton, William; Magid, Lee // Review of Scientific Instruments;Feb1994, Vol. 65 Issue 2, p412 

    A cell for examining the density profile of sheared fluids at the solid-liquid interface by neutron reflectometry is presented. This cell has also proven valuable in examining near-surface bulk structures in the plane perpendicular to the shear flow using small angle neutron scattering. The...

  • Stokes shear flow over a grating: Implications for superhydrophobic slip. Chiu-On Ng; Wang, C. Y. // Physics of Fluids;Jan2009, Vol. 21 Issue 1, pN.PAG 

    A semianalytical model based on the method of eigenfunction expansions and domain decomposition is developed for Stokes shear flow over a grating composed of a periodic array of parallel slats, with finite slippage on solid surfaces and infinite slippage on the bottom of troughs mimicking a...

  • Prediction of Hot Tear Formation in Vertical DC Casting of Aluminum Billets Using a Granular Approach. Sistaninia, M.; Drezet, J.-M.; Phillion, A.; Rappaz, M. // JOM: The Journal of The Minerals, Metals & Materials Society (TM;Sep2013, Vol. 65 Issue 9, p1131 

    A coupled hydromechanical granular model aimed at predicting hot tear formation and stress-strain behavior in metallic alloys during solidification is applied to the semicontinuous direct chill casting of aluminum alloy round billets. This granular model consists of four separate...

  • Numerical study of Rayleigh wave transmission through an acoustic barrier. Lamkanfi, Ebrahim; Declercq, Nico F.; Van Paepegem, Wim; Degrieck, Joris // Journal of Applied Physics;Jun2009, Vol. 105 Issue 11, p114902-1 

    Recent experiments [N. F. Declercq and E. Lamkanfi, Appl. Phys. Lett. 93, 2 (2008)] showed evidence of the relationship between the generation of leaky Rayleigh waves and the formation of the two reflected lobes and a null strip for bounded beam incidence at the Rayleigh angle. The evidence was...

  • Permeability computation on a REV with an immersed finite element method. Laure, P.; Puaux, G.; Silva, L.; Vincent, M. // AIP Conference Proceedings;5/4/2011, Vol. 1353 Issue 1, p978 

    An efficient method to compute permeability of fibrous media is presented. An immersed domain approach is used to represent the porous material at its microscopic scale and the flow motion is computed with a stabilized mixed finite element method. Therefore the Stokes equation is solved on the...

  • Scattering from an infinite, finitely conducting cylinder by finite element analysis. Bruno, A. B.; Brauer, J. R. // Journal of Applied Physics;4/15/1988, Vol. 63 Issue 8, p3200 

    Focuses on a study which evaluated the scattering of plane electromagnetic waves from an infinite, finitely conducting cylinder by the finite element method (FEM). Methodology of the study; Discussion on the computer program used; Results of the FEM calculation; Discussion on results for...

  • Scattering by small defects in the neighbourhood of a fluid-solid interface. Williams, DP; Williams, D.P.; Craster, RV; Craster, R.V. // IMA Journal of Applied Mathematics;Oct98, Vol. 61 Issue 2 

    Evaluates the scattering of incident plane elastic waves by a variety of different defects that lie upon a fluid-solid interface using matched asymptotic expansions. Three examples illustrating the occurrences of three different canonical situations; Identification of the leading-order...

  • A Nitsche embedded mesh method. Sanders, Jessica; Laursen, Tod; Puso, Michael // Computational Mechanics;Feb2012, Vol. 49 Issue 2, p243 

    A new technique for treating the mechanical interactions of overlapping finite element meshes is proposed. Numerous names have been applied to related approaches, here we refer to such techniques as embedded mesh methods. Such methods are useful for numerous applications e.g., fluid-solid...

  • Separate-type scanner and wideband high-voltage amplifier for atomic-resolution and high-speed atomic force microscopy. Miyata, Kazuki; Usho, Satoshi; Yamada, Satoshi; Furuya, Shoji; Yoshida, Kiyonori; Asakawa, Hitoshi; Fukuma, Takeshi // Review of Scientific Instruments;Apr2013, Vol. 84 Issue 4, p043705 

    We have developed a liquid-environment atomic force microscope with a wideband and low-noise scanning system for atomic-scale imaging of dynamic processes at solid/liquid interfaces. The developed scanning system consists of a separate-type scanner and a wideband high-voltage amplifier (HVA). By...


Read the Article


Sorry, but this item is not currently available from your library.

Try another library?
Sign out of this library

Other Topics