PurposeTo present the detailed implementation processes of the ideal algorithm for two-dimensional compressible flows based on Delaunay triangular mesh, and compare the performance of the SIMPLE and ideal algorithms f...
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PurposeTo present the detailed implementation processes of the ideal algorithm for two-dimensional compressible flows based on Delaunay triangular mesh, and compare the performance of the SIMPLE and ideal algorithms for solving compressible problems. What's more, the implementation processes of Delaunay mesh generation and derivation of the pressure correction equation are also ***/methodology/approachProgramming completely in C++.FindingsFive compressible examples are used to test the SIMPLE and ideal algorithms, and the comparison with measurement data shows good agreement. The ideal algorithm has much better performance in both convergence rate and stability over the SIMPLE ***/valueThe detail solution procedure of implementing the ideal algorithm for compressible flows based on Delaunay triangular mesh is presented in this work, seemingly first in the literature.
The inner doubly iterative efficient algorithm (ideal), an advanced fully implicit algorithm for solving the pressure-velocity coupling problem, lacks a comprehensive implementation procedure on commonly used collocat...
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The inner doubly iterative efficient algorithm (ideal), an advanced fully implicit algorithm for solving the pressure-velocity coupling problem, lacks a comprehensive implementation procedure on commonly used collocated unstructured grids. Therefore, this study provides a thorough demonstration of the fundamental principles, solving procedures, discretizations of momentum and pressure equations, Rhie-Chow interpolation implementation, mass continuity processing, and boundary condition treatment associated with the ideal algorithm on a collocated unstructured grid. Additionally, a comparative analysis between the semi-implicit method for pressure-linked equations (SIMPLE) and the ideal algorithm is conducted concerning computational efficiency under different grid types and flow conditions. The results indicate a significantly higher computational efficiency achieved by the ideal algorithm across all tested cases, attributed to its ability to overcome two fundamental assumptions inherent in the SIMPLE algorithm. The average acceleration ratio for these cases is approximately 3.13 (tSIMPLE/tideal). This study serves as a valuable reference for the further development and application of the ideal algorithm in solving flow problems with complex irregular domains discretized by unstructured grids.
Numerical simulation of engineering applications usually has a relatively low requirement for time resolution but a high requirement for computational efficiency. In order to efficiently simulate the unsteady engineer...
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Numerical simulation of engineering applications usually has a relatively low requirement for time resolution but a high requirement for computational efficiency. In order to efficiently simulate the unsteady engineering problems, a large time step unsteady solver for incompressible flows is developed based on the most popular open-source CFD software - OpenFOAM. In this solver, the coupling between velocity and pressure is solved using the ideal algorithm, which was first proposed by the present author. Then, two test cases are performed to verify the performance superiority of the developed solver. The results indicate that the ideal algorithm can converge to the steady-state solution at a much larger time step. Compared with the PISO and PIMPLE algorithms, the ideal algorithm can save the computational time by 34.9-88.8% and 19.8-94.1%, respectively. The developed solver has all the advantages of OpenFOAM software, which has a significant benefit in simulating the unsteady incompressible flows of engineering applications.
The ideal algorithm is an efficient and robust pressure-velocity coupling algorithm, which has been applied in a variety of fluid flow and heat transfer problems. However, the further development of the ideal algorith...
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The ideal algorithm is an efficient and robust pressure-velocity coupling algorithm, which has been applied in a variety of fluid flow and heat transfer problems. However, the further development of the ideal algorithin encounters with two key issues: it is hard to be mastered by other researchers and difficult to be extended to complex engineering problems. In order to overcome these two issues, the ideal algorithm is implemented in the world's most widely used open source CFD software - OpenFOAM. In that way, it is convenient for any researcher to employ the ideal algorithm to solve complex fluid flow problems. Then, the performance of ideal algorithm is analyzed with focus on complex steady-state incompressible fluid flow problems. The results indicate that the ideal algorithm is superior to the SIMPLE and SIMPLEC algorithms in convergence and robustness for complex cases. In particular, the ideal algorithm can reach convergence, whereas the SIMPLE and SIMPLEC algorithms cannot obtain convergent solution in some cases. This research lays a foundation for a wider application of the ideal algorithm in complex engineering problems.
Recently, an efficient segregated algorithm for incompressible fluid flow and heat transfer problems, called inner doubly iterative efficient algorithm for linked equations (ideal), has been proposed by the present au...
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Recently, an efficient segregated algorithm for incompressible fluid flow and heat transfer problems, called inner doubly iterative efficient algorithm for linked equations (ideal), has been proposed by the present authors. In the algorithm there exist inner doubly iterative processes for pressure equation at each iteration level, which almost completely overcome two approximations in SIMPLE algorithm. Thus, the Coupling between velocity and pressure is fully guaranteed, greatly enhancing the convergence rate and stability of solution process. However, validations have only been conducted for two-dimensional cases. In the present paper the performance of the ideal algorithm for three-dimensional incompressible fluid flow and heat transfer problems is analyzed and a systemic comparison is made between the algorithm and three other most widely used algorithms (SIMPLER, SIMPLEC and PISO). By the comparison of five application examples, it is found that the ideal algorithm is the most robust and the most efficient one among the four algorithms compared. For the five three-dimensional cases studied, when each algorithm works at its own optimal under-relaxation factor, the ideal algorithm can reduce the computation time by 12.9-52.7% over SIMPLER algorithm, by 45.3-73.4% over SIMPLEC algorithm and by 10.7-53.1% over PISO algorithm. Copyright (C) 2009 John Wiley & Sons, Ltd. C,
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