Eventos Anais de eventos
COBEM 2023
27th International Congress of Mechanical Engineering
Numerical study of the influence of the distance between the inlet boundary condition and the obstacle in external flow
Submission Author:
Cleberson Matos , SP , Brazil
Co-Authors:
Cleberson Matos, José Emanuel da Silva Montiel, Valentina Ferro Antunes de Oliveira, Laís Corrêa, Fernando Kurokawa
Presenter: Cleberson Matos
doi://10.26678/ABCM.COBEM2023.COB2023-1458
Abstract
Computational Fluid Dynamics (CFD) has been widely employed to study and analyze the behavior of fluids in physical systems. Studies on mesh convergence have been necessary for validation and application of models, as well as for replication of experimental cases. When dealing with external flows, the inappropriate positioning of the inlet boundary condition can provide inaccurate numerical results, causing significant changes in the velocity field and drag coefficient of a simulation. An insufficiently large distance could cause a disturbance at the inlet and alter the results, while an unnecessarily large distance would increase the computational cost of the simulation. In this context, this work aims to contribute to the topic by means of a numerical analysis of the influence of the distance between the inlet boundary condition and the object, verifying the existence of interferences through analysis of the velocity field and the drag coefficient. To do so, a cylinder with a diameter of 1 m was taken as a basis, which has numerical and experimental results available in the literature. The methods used consist of modeling a mesh capable of producing results that agree with the available literature data, varying the distance between the inlet and the object thereafter. For each simulation performed, the velocity field, drag coefficient, lift coefficient and pressure coefficient were obtained and subsequently compared. The computational simulations developed and presented in this work were carried out with the aid of the CFD software OpenFOAM, using LES (Large-Eddy Simulation) Smagorinsky turbulence model. The results obtained indicated that from a certain distance onward, the variation of the velocity field became significantly reduced, suggesting that the coefficients started to converge to a specific value. The methodology presented in this work can be applied using other CFD methods, so that the results will be useful for later applications.
Keywords
Computational fluid dynamics (CFD), Inlet distance, Mesh conversion, Velocity field, drag coefficient
