Eventos Anais de eventos
COBEM 2023
27th International Congress of Mechanical Engineering
MESH GENERATION METHODOLOGY FOR NUMERICAL SIMULATION OF FLOW WITHIN MULTILOBE PROGRESSING CAVITY PUMPS
Submission Author:
TULIO RAFAEL PORTO , PB , Brazil
Co-Authors:
TULIO RAFAEL PORTO, Joao Alves de Lima, Tony Herbert Freire de Andrade, Tales Dmitri Araujo Lopes
Presenter: Joao Alves de Lima
doi://10.26678/ABCM.COBEM2023.COB2023-2056
Abstract
The success of a tool in oil production depends on understanding the physical phenomena involved in its operation. Multi-lobe Progressive Cavity Pumps (PCPs) are extensions of traditional mono-lobe PCPs designed to operate with high oil flow rates, are capable of transporting fluids with different physical properties, and have high resistance to solid abrasives. These pumps are made up of a metallic helical rotor that moves inside an elastomeric or metallic stator with cavities in helical shape and number of lobes increased by one unit in relation to the rotor. The rotational movement imprinted on the rotor promotes the formation of transient sealing cavities that generate a spiral movement in the transported fluid, raising its pressure, from the suction to the discharge of the pump. Due to the geometric complexity related to the flow inside these machines, most attempts to describe the fluid dynamics of multilobe PCPs use simplified models, which do not consider the details of the turbulent, three-dimensional and transient flow that occurs inside these pumps. In this sense, this work proposes a methodology for generating mobile and deformable meshes with optimized topologies to be used in computational simulations of flows within multilobe PCPs, through full integration with the Ansys CFX® software. This methodology uses modified hypocycloid curves to describe the geometry of the PCP cross sections, according to the kinematics and to the helical structure of the pump. Furthermore, iterative methods are used to determine the intersection points between radial lines and the modified hypocycloid curves. These points, calculated over the entire cross-section, along the radial lines and the axial direction, determine the fluid domain to be analyzed, at each instant of time, considering all positions relative to the multilobe PCP operation. With this methodology it is possible to produce structured and three-dimensional meshes with small deformations. Meshes with these characteristics are not obtained by applying the traditional mesh generation methods available in commercial CFD packages, which, for large and cyclic displacements, produce meshes with large deformations and unstructured, inefficient to describe the flow in this type of geometry. The mesh generation methodology presented in this work was developed in Fortran 90 language, which can be used as a dynamic library to be executed in the Ansys CFX® software or as an independent program.
Keywords
Multilobe Progressing Cavity Pump, Structured Mesh Generation, 3D- Unsteady Computational Simulation
