The paper presents a three-dimensional numerical model that describes the operation of a gear pump, taking into account turbulence and cavitation. The model proposed is implemented in the ANSYS CFX software package. The algorithm for the simulation of moving boundaries (rotation of gears) is based on the immersed solid method. The formation of cavitation in the flow of a viscous incompressible fluid is simulated using a homogeneous two-phase model. The adequacy of the numerical analog developed was verified: on its basis, the analysis of the stability and convergence of the solution was carried out. A series of numerical experiments corresponding to the experimental design stage of creating a fuel system for a promising gas turbine engine were conducted. The technical characteristics of the pump—flow rate, cavitation localization zones, and the degree of cavitation—were obtained. The results of simulation for various operation modes of the unit under study, with different rotational speeds of the gears, are presented. The calculated flow rates for the single-phase (without cavitation) and two-phase flow model are compared with the data of a theoretical calculation using an engineering technique. The supposed cavitation formation zones and the cavitation level are shown and substantiated. The cavitation flow of a real liquid (aviation kerosene) is considered: depending on the rotational speed of the gear, the localization and relative volume of regions subject to cavitation, its concentration, and its possible effect on the consumption rate of the pump and its wear resistance are studied. The simulation results are presented in the form of functional dependences and patterns of the location of cavitation zones. The numerical model of a gear pump makes it possible to carry out numerical experiments instead of expensive full-scale physical experiments and give recommendations for preventive improvement of the design even before the production of prototype products.

The article addresses the modeling of the process of manufacturing a large-sized shell, given the thermomechanical behavior and viscoelasticity of the composite mandrel. The results of the experimental identification of viscoelasticity parameters of the examined material are presented. A numerical algorithm for adapting the experimental data for the ANSYS Mechanical APDL finite element analysis package is proposed. A Prony series expansion of the relaxation kernel is used as a model for describing the material behavior. The effect of temperature on the rate of relaxation processes is taken into account through the application of a temperature-time analogy according to the Williams–Landel–Ferry formula. The selected model with the calculated parameters was implanted into the commercial package of ANSYS Mechanical APDL. Simulation of two process steps of manufacturing a large-sized product was performed: winding and heat treatment of the shell. For this purpose, the quasistatic problem of mechanics and unsteady thermal conduction under conditions of convective heat transfer were solved by the finite element method. The influence of thermomechanical behavior of the mandrel material on the normal pressure acting on the mandrel surface as a function of temperature and force factors was estimated quantitatively and qualitatively. It was found that with respect to the nonlinear behavior of the composite material, the pressure level decreases by 50% compared to the case of using models of elastic behavior. This result justifies the importance of using complex models of material behavior in studying long-term technological processes, especially those associated with high-temperature effects.