Investigation of Radial Turbocharger Turbine Characteristics under Real Conditions 2009-01-0311
The paper deals with investigation of flow characteristics of turbocharger turbine under real operating conditions on engine by means of combination of experimental data and advanced 1-D code for combustion engine simulation.
Coupling simulations tools with the results of measurements provides the engineers with data which are difficult or impossible to measure. For instance by means of a three pressure analysis (TPA) applicable on engine cylinder the engineers can obtain burn rate, valve flow and residual gas compound from measured pressure traces in cylinder and at inlet and outlet ports.
A method for turbocharger turbine on engine identification similar in principle to the three pressure analysis has been applied on radial turbine with variable geometry. A new computational module has been developed to allow identification of instantaneous flow and efficiency characteristics of the turbine.
The method is based on simultaneous measurement of turbine inlet and outlet average pressure as well as pressure oscillations and instantaneous turbocharger speed measurement. Measured data were then used as boundary conditions for 1-D simulation model.
The method allows modifications of steady state turbine characteristics towards the pulsating flow characteristics. Steady state engine operation has been investigated in this phase.