Experimental approach for the characterization and performance analysis of twin entry radial-inflow turbines in a gas stand and with different flow admission conditions

In an internal combustion engine, twin entry turbine operates under different unequal admission conditions by feeding the turbine with a dissimilar amount of flow in each entry for a majority of the time. Despite of the impact on turbine performance, normal characteristic maps of these turbines are usually available only for full admission conditions. The current study investigates the best way of building characteristic maps of twin entry radial inflow turbines working under different admission conditions. The mass flow conditions are varied independently for each entry and results are examined to characterize the turbine performance parameters. The new methodology provides a practical approach regarding the reduced turbine speed; mass flow ratio; pressure ratios and efficiencies of a twin entry turbine. The most important conclusion of this work is the protocol of data analysis itself, which allows systematizing the testing procedure of this type of turbines with different steady flow admission and in quasi-adiabatic conditions. By sorting the experimental data in an orderly manner through proposed analysis, the readers can get benefit of this procedure to calibrate their own quasi-steady models for both: mass flow rate and efficiency; or to build new quasi-steady models with clear merit functions for fitting.