Nonlinear Finite Element Analysis-Based Flow Distribution Model for Engineering Practice

• Main Authors: Tomas Letal, Vojtech Turek, Dominika Fialova
• Format: Article
• Language: English
• Published: AIDIC Servizi S.r.l. 2019-10-01
• Series: Chemical Engineering Transactions
• Online Access: https://www.cetjournal.it/index.php/cet/article/view/10478

In engineering practice, it is common that heat transfer equipment containing tube bundles are designed under the assumption of uniform flow distribution. Such a flawed approach may easily lead to various operating problems (increased local fouling rates, mechanical failures, etc.) and significantly shortened service life. Accordingly, knowing the flow pattern in the bundle is crucial to proper design of the respective apparatuses. Although computational fluid dynamics (CFD) models yield very accurate data, due to their inherent computational cost they are not really suitable for evaluation of large sets of possible flow system geometries. Algebraic or otherwise greatly simplified models, on the other hand, are acceptable in terms of computational performance, but generally suffer from low accuracy and limited applicability to more complex meshes. This paper therefore proposes a computationally efficient flow distribution model whose principle is analogous to nonlinear finite element analysis (FEA). Unlike in many other simplified models, no special correction algorithms or user modifications are needed here because the underlying system of equations is solved in the matrix form and the corrector step is mesh-independent. Additionally, results provided by the model are compared to the data obtained using detailed CFD analyses of several different flow systems. Although the accuracy of the model does not match that of CFD, it can still be used at the beginning of a design process to discard the obviously unsuitable options, which would otherwise have to be evaluated via lengthy CFD simulations.