Fast three-dimensional heat transfer model for computing internal temperatures in the bearing housing of automotive turbochargers

Abstract

Each of the elements that make up the turbocharger has been gradually improved. In order to ensure that the system does not experience any mechanical failures or loss of efficiency, it is important to study which engine-operating conditions could produce the highest failing rate. Common failing conditions in turbochargers are mostly achieved due to oil contamination and high temperatures in the bearing system. Thermal management becomes increasingly important for the required engine performance. Therefore, it has become necessary to have accurate temperature and heat transfer models. Most thermal design and analysis codes need data for validation; often the data available fall outside the range of conditions the engine experiences in reality leading to the need to interpolate and extrapolate disproportionately. This article presents a fast three-dimensional heat transfer model for computing internal temperatures in the central housing for non-water cooled turbochargers and its direct validation with experimental data at different engine-operating conditions of speed and load. The presented model allows a detailed study of the temperature rise of the central housing, lubrication channels, and maximum level of temperature at different points of the bearing system of an automotive turbocharger. It will let to evaluate thermal damage done to the system itself and influences on the working fluid temperatures, which leads to oil coke formation that can affect the performance of the engine. Thermal heat transfer properties obtained from this model can be used to feed and improve a radial lumped model of heat transfer that predicts only local internal temperatures. Model validation is illustrated, and finally, the main results are discussed.

Modelling and optimal control of energy-saving-oriented automotive engine thermal management system

“…The indirect mass is defined by eq. (3), where Q ind is the indirect mass heat, m ind -represents the indirect mass, k -the thermal conductivity, A -the heat transfer area, T dir -represents the direct heating mass temperature, and T ind -the indirect mass temperature [6]:…”

Experimental validation of a one-dimensional twin-entry radial turbine model under non-linear pulse conditions

“…In single threaded simulations, the model needs 60 seconds for each single second of simulated time in an x86 CPU running at 3.2 GHz. It can easily be used coupled with other submodels of the turbocharger, taking into account the compressor quasi-steady map extrapolation [31], the heat transfer [32] [33] [34] or the mechanical losses in the bearings [35].…”

Effects of ported shroud casing treatment on the acoustic and flow behaviour of a centrifugal compressor

“…The walls were modelled as smooth with no-slip boundary conditions. As a first approach an adiabatic model was chosen, although it must be noted that models for estimating the impact of heat transfer are available 35,36 if desired.…”