Bearing System Development - A Continuous Challenge for High Speed Turbomachinery


Nom: 
Kostandin Gjika (Honeywell Garrett)
Lieu Evenemement: 
Département GMSC, Grande Salle de réunion
Date: 
Jeudi, 21 Juin, 2018 - 10:00
Description: 

Bearing System Development - A Continuous Challenge for High Speed Turbomachinery

 

The lecture concerns “Turbomachinery Nonlinear Rotordynamics & Bearing System: Fundamentals, Modeling and Experimental aspects. Application on High Speed Turbochargers”.
In a first step an introduction on Automotive Turbocharging following up by a description of the main turbocharger fundamental technologies will be presented.
Current trends for advanced automotive engines focusing on downsizing, better fuel efficiency and lower emissions have led to several changes in turbocharger bearing systems design and technology. Automotive turbochargers run faster and use engine oils with very low viscosity under high oil inlet temperature and low feed pressure. The development of high performing bearing systems, marrying innovation with reliability, is a persistent challenge.
Honeywell approach for turbocharger rotor-bearing system development will be presented.
Modeling aspects of nonlinear dynamic behavior of rotor-radial bearing system (RBS) incorporating two hydrodynamics oil films commonly used in turbochargers are described. An in house fluid bearing code predicts bearing rotational speed, operating inner and outer bearing film clearances, effective oil viscosity, and hydrostatic load. This input is used in a rotordynamics code in order to predict the nonlinear lateral dynamic response of the rotor-bearing system. The model is validated by test data from a high speed turbocharger running up to 250,000 rpm with 0W30 oil type, 150 °C oil inlet temperature, and 1 & 4 bars oil feed pressures. The tests are conducted on the so-called “rotordynamics technology cell” using a high performance data acquisition system. Prediction and measured synchronous response and total motion are in good agreement. Both demonstrate the nonlinear character of RBS behavior including several subsynchronous frequencies components across the operating speed range.
Honeywell experimental tools and approach for qualification of the bearing system, and research & development purposes will be outlined.
A breakthrough and differentiated approach for “Turbocharger rotor-bearing system dynamic stability – Manufacturing process – Vehicle vibro-acoustics” performance optimization will be presented too.
Test cells push technological boundaries on bearing systems, predictive tools add value to customer partnership.

Departement: 
D3







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