Aerodynamic and Thermal Analysis of Bump Type Gas Foil Thrust Bearing for Cryogenic Helium Turboexpander

8 Pages Posted: 19 Apr 2019

See all articles by Jitesh Kumar

Jitesh Kumar

National Institute of Technology, Rourkela, Students

Ch. Rewant

National Institute of Technology, Rourkela

Hitesh Kumar Sinha

National Institute of Technology, Rourkela

Suraj Kumar Behera

National Institute of Technology, Rourkela

Date Written: December 13, 2018

Abstract

Gas Foil Bearings (GFBs) are used for several high-speed applications for its compliant behavior to tailor its damping and stiffness. One of the high-speed application is the cryogenic turboexpander and they are used to refrigerate the gas stream in a liquefier. This article deals with the aerodynamic and thermodynamic analysis of bump type gas foil thrust bearings (BGFTBs), which are used to support the axial load of the helium turboexpander with a design speed of 2,40,000 rpm. The BGFTBs consists of very thin top and bump foils attached to the bearing base. The wedging action between the shaft collar and top foil is responsible for the development of aerodynamic pressure and this aerodynamic pressure supports the axial load of the rotor. Due to restricted converging passage for the gas flow between the collar and top foil, the process gas is likely to rise in temperature and distort the thin foils of the bearings. This paper presents a simulation method to analyze the aerodynamic and thermal behavior of the BGFTBs. The gas film is modeled using Reynold’s equation. The structural and Reynold’s equations are coupled together to predict the film thickness, pressure distribution and load carrying capacity. Further, the gas film is modeled by using an energy equation to predict the thermal characteristics. The Couette Approximation is used to predict the temperature distribution of the gas film. This approximation helps to delink the energy equation with Reynolds equation.

Keywords: Turboexpander, Gas foil bearing, Bump foil bearings, Couette Approximation

Suggested Citation

Kumar, Jitesh and Rewant, Ch. and Sinha, Hitesh Kumar and Behera, Suraj Kumar, Aerodynamic and Thermal Analysis of Bump Type Gas Foil Thrust Bearing for Cryogenic Helium Turboexpander (December 13, 2018). Proceedings of TRIBOINDIA-2018 An International Conference on Tribology. Available at SSRN: https://ssrn.com/abstract=3347076 or http://dx.doi.org/10.2139/ssrn.3347076

Jitesh Kumar (Contact Author)

National Institute of Technology, Rourkela, Students ( email )

Rourkela, Odisha 769008
India

Ch. Rewant

National Institute of Technology, Rourkela ( email )

Rourkela
Rourkela, Odisha 769008
India

Hitesh Kumar Sinha

National Institute of Technology, Rourkela ( email )

Rourkela
Rourkela, Odisha 769008
India

Suraj Kumar Behera

National Institute of Technology, Rourkela ( email )

Odisha
India

Register to save articles to
your library

Register

Paper statistics

Downloads
12
Abstract Views
136
PlumX Metrics