CNearest

This package implements a method for solving problems in very viscous fluid dynamics. The package provides a method for calculating the drag force and moment on rigid spheres and spheroids immersed in a 'simple' (Newtonian) viscous fluid, in the limit where inertia is negligible relative to viscosity (zero Reynolds number / Stokes flow).

This system is particularly relevant in microscale biological fluid dynamics systems and colloids; one specific application is the calculation of the diffusion tensor of a specified structure.
The underlying numerical algorithm is the nearest-neighbour implementation of regularised stokeslets; this approach enables efficient and accurate calculations requiring only surface point discretisations rather than surface or volumetric meshes.

The calculated flow field is also ensured to be regular throughout the interior, exterior and surface of the body. The package also serves as a library that can be utilised with the user's own surface discretisation to calculate the force and moment on any given three dimensional body undergoing rigid body motion.

The library also forms an extensible toolkit for problems involving calculations of flow fields due to flexible motions, such as cilia-driven transport, motility / swimming due to flagellar movement or surface deformations, and integration with models of actively bending elastic bodies.