Generating fractal rough surfaces with the spectral representation method

On the Fractal Dimension of Rough Surfaces

Most natural surfaces and surfaces of engineering interest, e.g., polished or sandblasted surfaces, are self-affine fractal over a wide range of length scales, with the fractal dimension Df 1⁄4 2:15 0:15. We give several examples illustrating this and a simple argument, based on surface fragility, for why the fractal dimension usually is \2.3. A kinetic model of sandblasting is presented, which...

An Efficient Spectral Method for Acoustic Scattering from Rough Surfaces

An efficient and accurate spectral method is presented for scattering problems with rough surfaces. A probabilistic framework is adopted by modeling the surface roughness as random process. An improved boundary perturbation technique is employed to transform the original Helmholtz equation in a random domain into a stochastic Helmholtz equation in a fixed domain. The generalized polynomial chao...

Implicit Representation of Rough Surfaces

Implicit surface techniques provide useful tools for modeling and rendering smooth surfaces. Deriving implicit formulations for fractal representations extends the scope of implicit surface techniques to rough surfaces. Linear fractals modeled by recurrent iterated function systems may be de ned implicitly using either geometric distance or escape time. Random fractals modeled using Perlin's no...

Frequency-dependent viscous flow in channels with fractal rough surfaces

Methods for Generating Rough Surfaces in ANSYS

Many engineering fields, including tribology and MEMS, seek to use or alter the behavior of the system at the surface or at the interface between surfaces. Thus, the topography of the surface is of great interest and must be included in finite element simulations. Four methods for generating normally distributed rough surfaces using APDL are proposed. The resulting geometry, meshes, and solutio...