A Comparative Study of Turbulence Methods Applied to the Design of a 3D-Printed Scaffold and the Selection of the Appropriate Numerical Scheme to Simulate the Scaffold for Tissue Engineering

Abstract

Current commercial software tools implement turbulence models on computational fluid dynamics (CFD) techniques and combine them with fluid-structural interaction (FSI) techniques. There are currently a great variety of turbulence methods that are worth investigating through a comparative study in order to delineate their behavior on scaffolds used in tissue engineering and bone regeneration. Additive manufacturing (AM) offers the opportunity to obtain three-dimensional printed scaffolds (3D scaffolds) that are designed respecting morphologies and that are typically used for the fused deposition model (FDM). These are typically made using biocompatible and biodegradable materials, such as polyetherimide (PEI), ULTEM 1010 biocompatible and polylactic acid (PLA). Starting from our own geometric model, simulations were carried out applying a series of turbulence models which have been proposed due to a variety of properties, such as permeability, speed regime, pressures, depressions and stiffness, that in turn are subject to boundary conditions based on a blood torrent. The obtained results revealed that the detached eddy simulation (DES) model shows better performance for the use of 3D scaffolds in its normal operating regime. Finally, although the results do not present relevant differences between the two materials used in the comparison, the prototypes simulated in PEI ULTEM 1010 do not allow their manufacture in FDM for the required pore size. The printed 3D scaffolds of PLA reveal an elastic behavior and a rigidity that are similar to other prototypes of ceramic composition. Prototypes made of PLA reveal unpredictable variability in pore and layer size which are very similar to cell growth itself and difficult to keep constant.

A Combined Computational and Experimental Analysis of PLA and PCL Hybrid Nanocomposites 3D Printed Scaffolds for Bone Regeneration

“…In this paper, an experimental and computational assessment was performed with regards to PLA and PCL reinforced with CS/MWCNTs scaffolds with a rectangular-shaped scaffold design. The suitability for PLA scaffold fabrication for bone reconstruction applications is further supported due to its accelerated bone regeneration properties [9,13,21]. It should be taken into consideration that the material selected for scaffold design should also address properties (apart from mechanical strength) such as biocompatibility and degradation behavior.…”

“…By simulating fluid flow through the scaffold architecture, valuable insights into how different design elements impact permeability and wall shear stress (WSS) can be gained, affecting the scaffold's efficacy in supporting cellular activities. Permeability is a pivotal property governing the transport of nutrients and gases within the scaffold matrix, while WSS indicates the mechanical stimuli experienced by cells within the scaffold environment [5,6] Numerous studies have been published focusing on biocomposite scaffolds with various materials and geometries to support tissue and bone regeneration [7][8][9][10][11][12][13]. Kakarla et al [8] used the representative volume elements (RVE) method and FEA to study the maximum stress distributions and mechanical properties of boron nitride nanotubes (BNNTs)reinforced gelatin (G) and alginate (A) hydrogel.…”

Computational Modelling and Simulation of Scaffolds for Bone Tissue Engineering

“…Suffo et al discussed the differences between various turbulent flow modelling methods (Figure 12) [131]. These methods include Reynolds averaged Navier-Stokes (RANS) such as k-ε, k-ω (Wilcox model) and k-ω SST (shear stress transport), Reynolds stress models (RSM), large eddy simulation (LES), direct numerical simulation (DNS), the scale adaptive simulation (SAS), and detached eddy simulation (DES) models.…”

Feasibility of the manufacturing process of cork stoppers for spirits using vegetable and textiles fibers

“…Traditionally, the crowns where the cork spikes are embedded have been manufactured through an injection molding process. The top 5 used thermoplastic materials in the industry are polyethylene (PE), polypropylene (PP), polyvinyl chloride (PVC), polyethylene terephthalate (PET) and polystyrene (PS) [5]. These thermoplastics are mostly used in conventional manufacturing processes, such as injection or extrusion, but some of them are also becoming popular in additive manufacturing.…”