Related Experiment Video
Updated: Apr 18, 2026
08:49
Impacts of Free-falling Spheres on a Deep Liquid Pool with Altered Fluid and Impactor Surface Conditions
Published on: February 17, 2019
7.1K
High frequency backscattering by a solid cylinder with axis tilted relative to a nearby horizontal surface
Daniel S Plotnick1, Philip L Marston1, Kevin L Williams2
1Department of Physics and Astronomy, Washington State University, Pullman, Washington 99164-2814.
The Journal of the Acoustical Society of America
|January 26, 2015
Summary
Investigating solid cylinders on sand, this study reveals how vertical tilting changes acoustic backscattering. Tilting alters multipath interference, modifying the acoustic template and splitting observed features.
Area of Science:
- Acoustics
- Geophysics
- Oceanography
Background:
- Acoustic backscattering from solid cylinders in water is well-studied.
- Previous work examined cylinders on sand, focusing on grazing and viewing angles.
- Surface interference significantly alters backscattering spectra for proud cylinders.
Purpose of the Study:
- To investigate the effect of vertical cylinder tilt on acoustic backscattering.
- To understand how partial burial in sand modifies the acoustic template.
- To develop an approximation for relating spectral changes to cylinder tilt.
Main Methods:
- Analysis of backscattering spectra as a function of azimuthal angle.
- Modeling using a combination of geometrical and physical acoustics.
- Comparison with experimental data for cylinders on sand and metallic cylinders near a surface.
Main Results:
- Vertical tilt of a cylinder partially buried in sand alters multipath interference.
- This modification results in significant changes to the acoustic backscattering spectrum.
- A splitting in the azimuthal angle for broadside multipath features was observed and modeled.
- The findings were validated with tank experiments.
Conclusions:
- Cylinder tilt significantly impacts acoustic backscattering patterns.
- A simple approximation can model spectral changes due to tilt.
- The study provides insights into acoustic scattering from targets near sediment interfaces.
Related Concept Videos
01:16Perpendicular-Axis Theorem
4.8K
The perpendicular-axis theorem states that the moment of inertia of a planar object about an axis perpendicular to its plane is equal to the sum of the moments of inertia about two mutually perpendicular concurrent axes lying in the plane of the body.
Consider a circular disc of mass M and radius R lying along an x-y plane. The origin lies at the center of the disc, and the z-axis is perpendicular to the disc's plane. All three axes coincide at the disc's center. The moment of inertia of this...
Consider a circular disc of mass M and radius R lying along an x-y plane. The origin lies at the center of the disc, and the z-axis is perpendicular to the disc's plane. All three axes coincide at the disc's center. The moment of inertia of this...
4.8K
01:20Gauss's Law: Cylindrical Symmetry
10.2K
A charge distribution has cylindrical symmetry if the charge density depends only upon the distance from the axis of the cylinder and does not vary along the axis or with the direction about the axis. In other words, if a system varies if it is rotated around the axis or shifted along the axis, it does not have cylindrical symmetry. In real systems, we do not have infinite cylinders; however, if the cylindrical object is considerably longer than the radius from it that we are interested in,...
10.2K
01:10Deformation in a Circular Shaft
1.1K
One of the distinctive characteristics of circular shafts is their ability to maintain their cross-sectional integrity under torsion. In other words, each cross-section continues to exist as a flat, unaltered entity, simply rotating like a solid, rigid slab. To understand the distribution of shearing stress within such a shaft, consider a cylindrical section inside this circular shaft. This section has a length of L and a radius of R, with one end fixed. The radius of the cylindrical section is...
1.1K
01:15Thin-Walled Hollow Shafts
702
In analyzing a thin-walled hollow shaft subjected to torsional loading, a segment with width dx is isolated for examination. Despite its equilibrium state, this segment faces torsional shearing forces at its ends. These forces are quantitatively described by the product of the longitudinal shearing stress on the segment's minor surface and the area of this surface, leading to the concept of shear flow. This shear flow is consistent throughout the structure, indicating a uniform distribution of...
702
01:29Volumes of Solids of Revolution
464
Volumes of irregularly shaped objects can be systematically determined using the concept of solids of revolution. This approach begins with a region defined by a curve in a two-dimensional plane. When this region is rotated about a fixed line, known as the axis of revolution, it generates a three-dimensional object with rotational symmetry. Such objects frequently arise in mathematical modeling, physics, and engineering applications.When the region being rotated lies directly against the axis...
464
01:07Reflection of Waves
4.9K
When a wave travels from one medium to another, it gets reflected at the boundary of the second medium. A common example of this is when a person yells at a distance from a cliff and hears the echo of their voice. The sound waves (longitudinal waves) traveling in the air are reflected from the bounding cliff. Similarly, flipping one end of a string whose other end is tied to a wall causes a pulse (transverse wave) to travel through the string, which gets reflected upon reaching the wall. In...
4.9K