Turbocharger nonlinear rotordynamics


MAJOR APPLICATION: Passenger vehicle (PV) and commercial vehicle (CV) turbochargers, micro-turbomachinery


Sponsor: Honeywell Turbo Technologies (HTT) 2000-2012, Turbomachinery Laboratory

INDUSTRIAL FUNDING (00-12) $812,500


Download slide shows

2011, January

Research Progress Overview on Turbocharger NL Bearings and Rotordynamics

2010, September

8th IFToMM International Conference on Rotordynamics Seoul, Korea

Paper WeE3-2

Nonlinear Rotordynamics of Vehicle Turbochargers: Parameters Affecting Sub Harmonic Whirl frequencies and Their Jump

Undergraduate research
2008 poster

TC model validation and TC Housing Acceleration


Turbochargers supported on semi-floating ring bearings and fully-floating ring bearings. Donations from Honeywell Turbo Technologies

Objective: To advance (experimentally validated) computational tools for prediction of the dynamic forced response of turbocharger rotors supported on FRBs. Applications for PV (passenger vehicles) and CV (commercial vehicles)

Status: Honeywell Turbo Technologies continuously support this project since 2000. The turbocharger (TC) test rig was dismantled after testing three TC units. DAQ system and instrumentation developed to record shaft motions to 200 krpm, including floating ring speed. A Virtual Laboratory for prediction of TC response is currently in place. The work aims to correlate nonlinear model predictions with test data available from the sponsor Hot Gas Test Stands in LA and France. The computational tool allows for fast product development with substantial savings to the sponsor.


Current Work proprietary



Numerical predictions based on XLTRC2 and bearing nonlinear models (XLBRG) show excellent correlation with test data for a TC supported on fully-floating ring bearings as well as for a unit supported on semi-floating ring bearings. The side load due to the feed pressure must be accounted in the analysis to predict reliable results comparable to the test data.


The latest version of XLBRG features seven different heat convection models. In addition, based on bearing geometry, XLBRG features three types of bearing models:


a)     Bearing with inlet feed pressure at ONE END

b)     Bearing with inlet feed pressure at MIDPLANE

c)      Bearing with UNEQUAL LENGTHS (LEFT & RIGHT) inlet feed pressure at center between lands


Some of the major advances in analytical study conducted at Turbo Lab include but are not limited to:


a)     Predictions of linear and nonlinear responses of various Turbochargers (TC) with constant shaft speed

b)     Effect of compressor cross coupled stiffness and thrust bearing moment coefficients on TC dynamic response

c)      Effect of increasing inner film clearance on TC shaft motions

d)     Predictions of TC transient speed response with various acceleration and deceleration rates

e)     Predictions of TC nonlinear response with engine housing base excitations

f)      Modifications of the XLTRC2 Excel GUI to be compatible with new bearing features in XLBRG


Please note that in most cases predictions are validated against test data. Rotor models developed in XLTRC2 are validated by measuring their free-free mode natural frequencies and mode shapes.











Example of a XLTRC2 TC rotor model supported on FRBs

























Predicted and measured TC dynamic response shaft speed 29 to 243 krpm



$ 208,340

Turbocharger Bearing Code Development

09/01/10 08/31/12

$ 438,160


Computational Analysis of Floating Ring Journal Bearings and Experimental Validation in a Turbocharger Test Rig Phase I-IV




$ 42,000

Feasibility Study of Bearing Technologies for Oil-Free Turbochargers



$ 129,000



Computational Analysis of Floating Ring Journal Bearings and Experimental Validation in a Turbocharger Test Rig






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