Investigation of the influence of radial grooves on the flow in an eccentrically deposited annulus using CFD numerical simulation

Abstract

Abstract. This paper evaluates the influence of radial grooves in the eccentrically deposited annulus using by mathematical modeling of fluid flow through each grooves. The inner cylinder (rotor) is eccentrically deposited and its movement is composed of two movements (rotation and precession). The outer cylinder is stationary and has radial grooves. In the first phase is defined a mathematical model of the flow, which is then applied to the 3D model of narrow gap with radial grooves. In this paper are present several variants of the computational domain with regard to the number of radial grooves. Based on the results of numerical simulations are evaluated basic variables such as pressure and velocity. There are also evaluated radial force (F r ) and axial force (F a ) acting on the rotor for different boundary conditions (different speeds of rotation and precession). Subsequently, the pressure gradients (Δp) are evaluated between the radial grooves for different computational domain. Results are compared to variant of narrow gap without radial grooves. Numerical simulation is realized in the program system ANSYS Fluent.

Analysis of the Impact of Special Constructions of Gap Seals on the Dynamics of Centrifugal Machines

“…The works of the creators of centrifugal machines [1][2][3][4][5][6] was devoted to the study of the relationship between the vibration characteristics of the rotor and the designs of gap seals. These works, as well as the needs of thermal and nuclear energy in feed, main circulation and other pumps for ever higher parameters stimulated a detailed study of the problems of hydrodynamics of gap seals and their effect on the vibration state of rotors of centrifugal machines [1,2,5,6]. Work on the creation of turbopump assemblies for high-power rocket engines for reusable spacecraft further raised the interest of researchers in the dynamic characteristics of gap seals and vibrations of rotors in seals [7,8,10].…”

“…The peculiarity of the works of most researchers of the influence of seals on the dynamics of a centrifugal machine is that the rotor and seals are considered as a closed hydromechanical system, in which the role of a connecting link is played by the flow of the pumped medium in throttling channels, inertial and hydrodynamic characteristics of the flow [3][4][5][6].…”

“…Thus, when choosing the design of gap seals, one must take into account not only their direct purpose -to reduce volumetric losses, but also their equally important function -to provide the necessary vibration characteristics of the rotor [6].…”

Methodology of Designing Sealing Systems for Highly Loaded Rotary Machines

“…For their creation, it is important to develop a methodological base and models of various types of seals [40]. On this basis the characteristics of medium losses, friction forces and vibration characteristics can be obtained [41,42]. Moreover, it is necessary to consider the peculiarities of their combination as part of complex sealing systems in order to achieve balance between sealing and vibration reliability, taking into account the hydrodynamic characteristics of seals [43,44].…”

Studying the Interaction of Liquid and Solid in the Flow of Liquid in Annulus by CFD Analysis

“…Flow of viscous fluid in the annulus is one of the important chapters of tribology. This issue is already deal to many researchers in history, but at present [1][2][3][4][5][6][7][8][9]. This is due to a wide range of practical applications where it is necessary to solve the generated force effects, such as hydrodynamic and hydrostatic journal bearings, seals and sealing gaps, that include narrow gaps where the flow losses are occurred, etc.…”