Optimal design of an annular thrust air bearing using parametric computational fluid dynamics model and genetic algorithms

The performance of air bearing is highly influenced by the geometrical parameters of its restrictor. This study aims to maximize the load-carrying capacity and stiffness of air bearing, and minimize its volume flow rate by optimizing the geometrical parameters of restrictor. To facilitate the calculation of air bearing performance, a parametric computational fluid dynamics model is developed. Then, it is combined with multiobjective optimization genetic algorithm to search the Pareto optimal solutions. Furthermore, as a case study, the optimal design of an annular thrust air bearing is implemented. The stiffness of air bearing is improved 38.5%, the load-carrying capacity is improved 33.9%, and the volume flow rate is declined 19.6%, which are finally validated by experiments. It proves the reliability of proposed parametric computational fluid dynamics model and genetic optimization algorithm.

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Computational Fluid Dynamics Model of Various Types of Rocket Engine Nozzles

International Review on Modelling and Simulations (IREMOS) ◽

10.15866/iremos.v13i1.18068 ◽

2020 ◽

Vol 13 (1) ◽

pp. 1

Author(s):

Konrad Pietrykowski ◽

Paweł Karpiński ◽

Radosław Mączka

Keyword(s):

Fluid Dynamics ◽

Computational Fluid Dynamics ◽

Rocket Engine ◽

Dynamics Model ◽

Computational Fluid Dynamics Model

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Computational Fluid Dynamics Thermohydrodynamic Analysis of Three-Dimensional Sector-Pad Thrust Bearings With Rectangular Dimples

Journal of Tribology ◽

10.1115/1.4025245 ◽

2013 ◽

Vol 136 (1) ◽

Cited By ~ 37

Author(s):

C. I. Papadopoulos ◽

L. Kaiktsis ◽

M. Fillon

Keyword(s):

Fluid Dynamics ◽

Computational Fluid Dynamics ◽

Carrying Capacity ◽

Thermal Effects ◽

Operating Conditions ◽

Load Carrying Capacity ◽

Performance Indices ◽

Thrust Bearings ◽

Load Carrying ◽

Texture Design

The paper presents a detailed computational study of flow patterns and performance indices in a dimpled parallel thrust bearing. The bearing consists of eight pads; the stator surface of each pad is partially textured with rectangular dimples, aiming at maximizing the load carrying capacity. The bearing tribological performance is characterized by means of computational fluid dynamics (CFD) simulations, based on the numerical solution of the Navier–Stokes and energy equations for incompressible flow. Realistic boundary conditions are implemented. The effects of operating conditions and texture design are studied for the case of isothermal flow. First, for a reference texture pattern, the effects of varying operating conditions, in particular minimum film thickness (thrust load), rotational speed and feeding oil pressure are investigated. Next, the effects of varying texture geometry characteristics, in particular texture zone circumferential/radial extent, dimple depth, and texture density on the bearing performance indices (load carrying capacity, friction torque, and friction coefficient) are studied, for a representative operating point. For the reference texture design, the effects of varying operating conditions are further investigated, by also taking into account thermal effects. In particular, adiabatic conditions and conjugate heat transfer at the bearing pad are considered. The results of the present study indicate that parallel thrust bearings textured by proper rectangular dimples are characterized by substantial load carrying capacity levels. Thermal effects may significantly reduce load capacity, especially in the range of high speeds and high loads. Based on the present results, favorable texture designs can be assessed.

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