Session: 19-05 Rotordynamics in high speed turbochargers

Paper Number: 102298

102298 - Effect of Leading-Edge Inlet Models on the Performance of Gas Bearings Operating in Highly Compressible Flow Regimes 

Reynolds equation has been widely used in modelling lubrication flow and load carrying performance prediction of fluid flow within gas bearings for a number of years. However, the underlying assumption of negligible fluid inertia is not a reasonable design approach philosophy as the operating speeds of such bearings become extremely high. In this paper, A 3D thermos-hydrodynamic model is presented to show effects of leading-edge inlet models on load carrying capacity of gas films for a rigid 3d bearing film, operating in high speed and highly compressible flow regimes. 

The model solves full 3-dimensional Navier-Stokes equations in laminar form coupled along with the gas film energy equation for gas temperature throughout the gas film. Results are also compared with a classical Reynolds equation-based 3D thermos-hydrodynamic model to show impact of choice of boundary condition treatments on performance and load carrying capacity predictions of such bearings, along with impacts of including inlet dead volume region modeling on gas film properties.

Further, some more results are discussed from solutions of 3-dimensional Navier-Stokes equations coupled with Peng-Robinson equation of state, to illustrate impacts on flows and load carrying capacity when considering highly compressible real gas effects for typical high density refrigerant flows within such bearings. 

Presenting Author: Arvind Prabhakar SIEMENS DISW

Presenting Author Biography: Arvind Prabhakar is a Turbomachinery Applications Engineer working at Siemens Industry Software. Arvind received his Masters degree in Mechanical Engineering from University of Texas at Arlington, TX, USA in 2016. His research interests include application of CFD in turbomachinery design, modeling and analysis using state of the art CFD methods, mean line aerodynamic blade design methods, CFD modeling for rotating flow, design methods for micro turbomachinery, and design, computational modeling and analysis of hybrid gas bearings for turbomachinery applications.

Authors:

Arvind Prabhakar SIEMENS DISW
Daejong Kim University of Texas at Arlington