Fluid Mechanics

Articles in this category.

Kelvin Wedge

What does $x^{\prime}$ mean in a Green’s function? — a linear algebra and operator view

In a Green's function \(G(x,x')\), the primed variable \(x'\) marks the source point — the location of a unit impulse — while \(x\) is the field point where the response is…

Fluid Mechanics
Kelvin Wedge

From the Spectral Dirichlet-Neumann Symbol to the Physical-Space Operator Identity

We show how the spectral relation ∑ Formula implies the physical-space operator identity ∑ Formula, by inverse Fourier transform and the commutation of \(\partial_z\) with the hori…

Fluid Mechanics
Kelvin Wedge

Fourier Coefficients of Quadratic Forms in $\cos \gamma$ for Steady Capillary-Gravity Waves

We factor the quadratic denominator \(a+b \cos \gamma+c \cos ^2 \gamma\) and reduce the computation of its Fourier coefficients to those of \(1 /(\cos \gamma-\lambda)\). Solving the associated…

Fluid Mechanics
Kelvin Wedge

Diagonalizing Azimuthal Mode Coupling via a Discrete Fourier Transform

We recast the azimuthal mode-coupled surface equations as a block-Toeplitz convolution in the mode index and diagonalize this coupling via a discrete Fourier transform in…

Fluid Mechanics
Kelvin Wedge

Cartesian Derivatives in Azimuthal Fourier–Hankel Space

claim: ∑ Formula

Fluid Mechanics
Kelvin Wedge

DFT Method Main

We consider the governing equations for water waves in the context of an inviscid fluid of infinite depth. The fundamental system of equations are ∑ Formula

Fluid Mechanics
Kelvin Wedge

Azimuthal Fourier Analysis

We introduce azimuthal Fourier expansion for functions with circular symmetry: we write \(f(r, \phi)\) as a sum of angular modes ∑ Formula, where ∑ Formula is obtained by integrati…

Fluid Mechanics
Kelvin Wedge

Operator Ladder Relations for Hankel Transforms of Bessel Type

Hankel–Bessel Ladder Identities Claim. For suitable \(f_m(r)\) and \(k>0\), ∑ Formula Here ∑ Formula.

Fluid Mechanics
PINN Ocean Flow

settings for PINN

This note introduces Ninja, PyTorch’s MPS backend, and NVIDIA DALI as tools relevant to setting up a PINN workflow. It outlines their roles and the hardware constraints to…

Fluid Mechanics
Kelvin Wedge

Surface Waves Generated by A Travelling Pressure Point

We study the free-surface response to a moving pressure point over finite depth using 2D Fourier transforms, contour deformation, and a radiation condition. By analysing poles…

Fluid Mechanics
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