The mesh was validated based on the Grid Convergence Index. A high quality mesh was built in Icem CFD software, applying more dense spacing in zone of micro-mixer and near to the walls. The discretization scheme was Phase-Coupled SIMPLE for Pressure- Velocity Coupling, SIMPLE for Pressure, Least Square Cell Based for the Gradient, QUICK for the Volume Fraction, First Order Implicit for Transient Formulation and Second Order Upwind for all other quantities. The convergence criterion was set to 0.001 and in order to achieve the convergence, the under relaxation factors of Volume Fraction, Moments and Species were set to 0.05. For this, the input velocity was not given as constant value but the fully developed flow profile of velocity, k and Оµ, corresponding to the given flow-rate was computed initially and loaded into the simulation. To save computational time, a symmetry plane was defined which cuts the reactor in longitudinal direction and the lengths of conduits feeding the Y-mixer was minimized to 0. Numerical simulation was carried using the Ansys Fluent CFD software, with a 3D double precision parallel steady state solver. Lakatos, in Computer Aided Chemical Engineering, 2014 3 Numerical details and simulation settings However, if desired you can enable/disable GPGPU acceleration of the AMG solver for coupled and scalar systems with the following text command and list each supported equation type allowing you to enable/disable GPGPU acceleration, choose between AMG and FGMRES solvers, and specify various solver options.Botond SzilГЎgyi. By default, GPU acceleration is applied automatically to coupled systems and not to scalar systems because scalar systems typically are not as computationally expensive. Since the segregated solver spends only 30 percent to 40 percent of its time in AMG, GPUs may not be advantageous because of memory transfer overhead costs. In flow only problems, typically the coupled solver spends about 60 percent to 70 percent of its time solving the linear system using AMG, making GPUs a good choice. However, speedup is significant for meshes that contain tens and hundreds of millions of cells because the overhead is relatively small compared to the computing time in the AMG solver.ДЄ coupled solver benefits most from GPUs. Problems that contain less than a few million cells do not gain speed from GPUs because of communication overheads incurred in transferring matrices from or to CPUs. When enabled, you can use GPU acceleration for AMG computations on linear systems with up to 5 coupled equations and computing requirements grow as the number of cells in the domain increase. AmgX can even use MPI to connect clusters of servers to solve very large problems that require dozens of GPUs. Fluent uses AmgX as its default linear solver, and it takes advantage of a CUDA-enabled GPU when it detects one. We call the library AmgX (for AMG Accelerated). NVIDIA partnered with ANSYS to develop a high-performance, robust and scalable GPU-accelerated AMG library. Comments can be added in the file with a semicolon at the beginning of the line. Journal File contains sequence of ANSYS Fluent commands that are identical to those that you would type interactively. It is a file that the background job will create, which will contain the output that ANSYS Fluent would normally print to the screen (for example, the menu prompts and residual reports). specifies the name of the output file.specifies the name of the journal or input file.That is, for nprocs solver processes running on M machines using ngpgpus GPUs per machine, we must have: Note that the number of processes per machine must be equal on all machines and ngpgpus must be chosen such that the number of processes per machine is an integer multiple of ngpgpus. specifies the number of GPUs per machine/node available in parallel mode.specifies the total number of CPU processors across all machines/nodes.specifies the 3d or 3ddp version of ANSYS Fluent.-g indicates that the program is to be run without the GUI or graphics.fluent command runs ANSYS Fluent interactively.

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