Heteregeneous computing for multi-phase blood flow simulations

With the advancement in hardware technology, we are able to reach unprecedented computational scalability and performance. Computational Science and Engineering applications now have highly effective computational resources other than CPU clusters. GPUs now have an important role in Computational Science and Engineering applications. In this study we have shown the efficiency of the usage of GPUs in Computational Fluid Dynamics (CFD). As CFD contains several numerical methods to solve Partial Differential Equations (PDE), some of the numerical methods are suitable for the usage of GPUs. Due to its computational architecture, GPUs can provide rather good performance in some algorithms. The CFD software we used for this thesis is OpenFOAM, an open source leading CFD software. As most of the expensive computational part of CFD takes place in the linear system solver, we have used tools such as Cufflink and Paralution which are able to integrate with OpenFOAM and uses GPU only in the linear system solver part of CFD applications. Other than these tools, there is other software called RapidCFD, based on OpenFOAM, that is developed to use GPUs for CFD applications in which GPU does not only take care of linear system solution but also discretization of PDEs and other calculations to prepare matrix system. All these tools have pros and cons as there is not one tool which is better than all, therefore, these softwares are compared in terms of their performance. We prefer to use Cufflink because it is developed for foam-extend which has Fluid Structure Interaction functionality which is sometimes important for some blood flow applications. The main purpose of this study is to make use of GPUs in blood flow especially using two-phase mixture flow approach. Therefore, we have also developed two-phase blood flow model with a specific non-Newtonian model for Red Blood Cells (RBCs) called modified Carreau-Yashuda Model. This realistic model has been established after experimental data for only blood flow, especially RBCs. Eventually, our blood flow model is expected to be used with FSI functionality for the flow in deep veins where venous valve mechanism is present. Two-phase blood flow modelling with the phases of RBCs and plasma is important to investigate the non-Newtonian behaviour of RBCs dispersed in plasma. Eventually, this thesis is focused on the usage of GPUs using OpenFOAM, mainly for the blood flow in deep veins.