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ISSN Online: 2377-424X

ISBN Print: 978-1-56700-474-8

ISBN Online: 978-1-56700-473-1

International Heat Transfer Conference 16
August, 10-15, 2018, Beijing, China

IMPROVEMENTS OF VELOCITY-CORRECTION FORMULAS FOR SIMPLE ALGORITHM

Get access (open in a dialog) DOI: 10.1615/IHTC16.cms.022962
pages 1713-1718

Abstract

In this paper, the velocity-correction formula of SIMPLE algorithm is reviewed and improved. For the acceleration of convergence, it is suggested that the corrected velocity and pressure should satisfy the discretized momentum equation without velocity relaxation. Furthermore, two methods are recommended to avoid divergence when adopting the above suggestion. On the one hand, a proper velocity relaxation factor is necessary for the discretized momentum equation when evaluating the temporary velocity so as to suppress the impact of the pressure error. And on the other hand, the correction of pressure must be confined so that the pressure will not change greatly. Besides, allocation factor is introduced with a clear physical meaning. It denotes the relationship between pressure correction and present grid velocity correction in the velocity-correction formula. A larger allocation factor can limit the change of pressure, which guarantees the robustness of the algorithm, while a smaller allocation factor can increase the convergence rate. Moreover, the numerical experiment, lid-driven cavity flow, is conducted for the improved SIMPLE algorithm. The numerical results demonstrate the effectiveness of the above improvements, as the time consumption ratio (compared to SIMPLEC) varies from 10% to 90%. And the recommended allocation factor is 8.