Smoothed particle hydrodynamics for blood flow analysis: development of particle lifecycle algorithm

The aim of this research was to facilitate the application of smoothed particle hydrodynamics (SPH) method to computational fluid dynamics analysis of turbulent flow through complex geometry blood vessels, and to compare it with the state-of-the-art finite element method (FEM). SPH offers the possibility to observe motion of fluid fragment or particle inclusion within the Lagrangian material framework, giving researchers greater insight into the Fluid–Structure interaction such as transportation and distribution of medical particles, or buildup of plaque in atherosclerosis. In order to generate the fluid flow in SPH, the particles are created at inlet, and destroyed at the outlet. In this paper, we present a novel lifecycle algorithm for generation and destruction of the particles using particle types, which is more flexible and suitable for the complex geometry models in comparison to the current state of the art commercial solutions, which use boundary planes. Our algorithm features mother and new-born particle types located at inlets used for the particle flow generation, and at the outlets, we have dying and killer particle types, which are used for deletion of particles. Based upon the current neighbors, the type of the particle is updated within the nearest neighbor search method, which is invoked in each time step. The capabilities of the new algorithm are demonstrated using a benchmark example and a realistic patient specific geometry, showing similar results, but the SPH advantages of particle tracking are yet to be utilized in our future work.