Permeability of bone scaffold with different pore geometries based on CFD simulation

Abstract

Scaffold plays a significant role in promoting cells proliferation and differentiation in bone regeneration. Permeability is one of the factors that affect the function as it is able to extract waste and supply nutrients or oxygen. The aim of this study was to design different pore shapes and to simulate its fluid model in order to predict permeability value of the scaffold. There were few steps in this project which were scaffold design, fluid simulation analysis and permeability calculation. Three different pore shapes were designed, which were circle, triangle, and hexagon by using the Solidworks software. Each scaffold was designed by the combination of three unit cells. Then, Computational Fluid Dynamics (CFD) simulation in the Ansys Fluent software was conducted to obtain the pressure drop from the pressure distribution within the pores. The permeability of scaffold was obtained by applying Darcy's permeability formula at inlet velocity of 0.001 m/s, 0.01 m/s and 0.1 m/s. Based on the calculation, the permeability for hexagon pore shape were 3.96691x10-07 m2, 3.52 x10- 07 and 1.92 x10-07 for 0.001 m/s, 0.01 m/s and 0.1 m/s inlet velocity, respectively. Therefore, by increasing the inlet velocities, permeability decreased for all types of scaffolds. Furthermore. hexagon pore shape showed the highest permeability value when compared with triangle and circle’s pore shape. Nevertheless, all pore shapes demonstrated permeability values that within the range of natural bone permeability.