Parallel CFD Simulations of Multiphase Systems: Jet into a Cylindrical Bath and Rotary Drum on a Rectangular Bath

Abstract

This chapter reveals that most of the developed commercial computational fluid dynamics (CFD) packages do not attempt to document the detailed algorithm for parallelising the code; even the ordinary solution strategies are tedious to learn sometimes. However, industrial engineers are more concerned about quick and correct solutions of their problems. Key features of this chapter are the use of the domain decomposition and encapsulated message passing to enable execution in parallel. A parallel version of a CFD code, FLUENT, has been applied to model some multiphase systems on a number of different platforms. The same models are considered for all the platforms to compare the parallel efficiency of CFD in those machines. The free surface, high gradient of the velocity, particle-particle, and particle-wall collisions make most industrial flow simulations computationally expensive. For many complex systems, like in the chapter, the computational resources that are required limit the detail modelling of CFD. The implementations of computational fluid dynamics codes on distributed memory architectures are discussed in the chapter, and they are analyzed for scalability. For commercial CFD packages, in many cases the solution algorithms are black boxes, even though parallel computing helps in many cases to overcome the limitations, as shown in the chapter. The performance of the code has been compared in terms of CPU, accuracy, speed and other factors. In short, this research is intended to establish a strategic procedure to optimize a parallel version of a CFD package, FLUENT. The parallelised CFD code shows the excellent efficiency and scalability on a large number of platforms.