Experimental characterization and mean line modelling of twin-entry and dual-volute turbines working under different admission conditions with steady flow

[ES] A pesar de la importancia de las turbinas radiales de doble entrada y doble voluta en el flujo para motores turboalimentados, sus mapas característicos y su modelado totalmente predictivo utilizando códigos dinámicos de gas 1D aún no están bien establecidos. La complejidad del flujo no estacionario y la admisión desigual de estas turbinas, cuando funcionan con pulsos de gases de escape del motor, las convierte en un sistema desafiante. Principalmente debido a la admisión de flujo desigual, se introduce un grado adicional de libertad con respecto a las turbinas conocidas como de una sola entrada con o sin álabes en el estator. Además, la adición de la segunda entrada a la voluta de la turbina aporta una complejidad adicional para determinar los parámetros de rendimiento de la turbina en estacionario estable y en condiciones de admisión desiguales.Esta tesis tiene como novedad principal un procedimiento simple para caracterizar experimentalmente y elaborar mapas característicos de estas turbinas con condiciones de flujo desiguales. Este método de análisis permite interpolar fácilmente dentro de los mapas distintivos propuestos o ajustar modelos simples y convincentes para calcular y extrapolar parámetros de rendimiento completo de turbinas de doble entrada y doble voluta. También hemos descrito aquí, dos modelos innovadores de línea media 0D que requieren una cantidad mínima de datos experimentales para calibrar ambos: es decir, el modelo de parámetros de flujo másico y el modelo de eficiencia isentrópica. Ambos modelos son predictivos en condiciones de admisión de flujo parcial o desigual utilizando como entradas: la relación de flujo másico entre ramas; la relación de temperatura total entre ramas; la relación de velocidad de álabe a chorro en cada rama y la relación de presión en cada rama. Estas cinco entradas generalmente son proporcionadas instantáneamente por códigos de dinámica de gas 1D. Por lo tanto, la novedad del modelo es su capacidad de ser utilizado de manera casi constante para la predicción del rendimiento de las turbinas de doble entrada y de doble voluta. Esto se puede lograr instantáneamente ya que las turbinas se calculan en condiciones de flujo pulsante y desigual en motores turbo alimentados. Además, se muestra una metodología para caracterizar el coeficiente de descarga de una válvula de alivio de presión. Para estimar el flujo de gas por la válvula de alivio en modelos unidimensionales, se correlaciona y valida un modelo empírico. Finalmente, se ha elaborado un mapa óptimo del coeficiente de descarga a través del método de interpolación, que puede integrarse en el sistema de modelo de motor turboalimentado completo unidimensional, para calcular el flujo másico real a través de la válvula de descarga y las válvulas de conexión de desplazamiento. Finalmente, los modelos han sido completamente validados al acoplarlos con un software de modelado unidimensional que simula tanto el banco de gas como el motor completo. Por un lado, los resultados de las validaciones del banco de gas muestran que el modelo puede predecir bien todas las variables de flujo estacionario. Por otro lado, los resultados de la validación de todo el motor muestran que el modelo es capaz de producir todas las variables del motor a plena carga como el flujo de masa de aire y el par de frenado con un buen grado de acuerdo con los datos experimentales.[EN] Despite the importance of radial in-flow twin-entry and dual-volute turbines for turbocharged engines, their characteristic maps and fully predictive modelling using 1D gas dynamic codes are not well established yet. The complexity of the un-steady flow and the unequal admission of these turbines, when operating with pulses of engine exhaust gas, make them a challenging system. Mainly due to the unequal flow admission, an additional degree of freedom is introduced to well-known single entry vanned or vaneless turbines. Moreover, the addition of the second inlet to the turbine volute brings extra complexity in determining the steady-state turbine performance parameters under unequal admission conditions. This thesis has a main novelty, which is a simple procedure for characterizing experimentally and elaborating characteristic maps of these turbines with unequal flow conditions. This method of analysis allows easy interpolating within the proposed distinctive maps or simple convincing models for calculating and extrapolating full performance parameters of twin-entry and dual-volute turbines. Here are also described two innovative 0D mean-line models that require a minimum quantity of experimental data for calibrating both: i.e. the mass flow parameter model and the isentropic efficiency model. Both models are predictive either in partial or unequal flow admission conditions using as inputs: the mass flow ratio and the total temperature ratio between the branches; the blade speed ratio and expansion ratio in each branch. These six inputs are generally instantaneously provided by 1D gas-dynamics codes.} Therefore, the novelty of the model is its ability to be used in a quasi-steady way for twin and dual-volute turbines performance prediction. This can be achieved instantaneously as turbines are calculated under pulsating and uneven flow conditions at turbocharged engines. Furthermore, a methodology for characterizing the discharge coefficient of a wastegate and scroll connection valve in a gas stand is shown. For estimating the gas flow over the same in one-dimensional models, an empirical model is correlated and validated. Finally, an optimal map of discharge coefficient has been drawn out through the interpolation method. This map can be integrated into the full one-dimensional turbocharged engine model system, in order to calculate the actual mass flow through the wastegate and scroll connection valves. Finally, the models have been fully validated by coupling them with one-dimensional modelling software and simulated both the gas stand and the whole engine measured points. On the one hand, the validation results from the gas stand simulation show that the model can predict well all steady flow variables. On the other hand, the validation results from the whole engine simulation show that the model is able to produce all the full load engine variables like air mass flow and brake torque in a reasonable degree of agreement with the experimental data.[CA] Malgrat la importància de les turbines radials amb doble entrada i de doble voluta per als motors turboalimentats, els seus mapes característics i el seu model completament predictiu mitjançant codis dinàmics de gas 1D encara no estan ben establerts. La complexitat del flux constant i l'admissió desigual d'aquestes turbines, quan funcionen amb polsos de gas d'escapament del motor, les converteixen en un sistema difícil. Principalment a causa de la admissió de flux desigual, s'introdueix un grau addicional de llibertat a les conegudes turbines vendes o d'entrada d'una sola entrada. A més, l'addició de la segona entrada a la voluta de la turbina aporta una complexitat addicional per determinar els paràmetres de rendiment de la turbina en estat estacionari en condicions d'admissió desigual. Aquesta tesi té com a novetat principal un procediment senzill per caracteritzar experimentalment i elaborar mapes característics d'aquestes turbines amb condicions de cabal desigual. Aquest mètode d'anàlisi permet interpolar fàcilment dins dels mapes distintius proposats o models senzills convincents per calcular i extrapolar paràmetres de rendiment complet de les turbines d'entrada doble i de doble voluta. Aquí també hem descrit dos models innovadors de línia mitjana 0D que requereixen una quantitat mínima de dades experimentals per calibrar tots dos: és a dir, el model de paràmetre de flux massiu i el model d'eficiència isentròpica. Els dos models són predictius en condicions d'admissió de flux parcial o desigual utilitzant com a entrada: la proporció de flux entre les branques; la relació total de la temperatura entre les branques; la relació velocitat fulla-raig a cada branca i la proporció de pressió a cada branca. Aquests cinc inputs generalment es proporcionen de manera instantània mitjançant codis de dinàmica de gas 1D. Per tant, la novetat del model és la seva capacitat d'utilitzar-se d'una manera quasi constant per a la predicció del rendiment de les turbines bessones i de doble voluta. Es pot aconseguir de forma instantània, ja que les turbines es calculen en condicions de flux pulsatòries i desiguals en motors turboalimentats. A més, es mostra una metodologia per a caracteritzar el coeficient de descàrrega d'una vàlvula de connexió per canals i desplaçaments en un suport de gas. Per estimar el flux de gas sobre el mateix en models unidimensionals, es correlaciona i valida un model empíric. Finalment, s'ha elaborat un mapa òptim de coeficient de descàrrega mitjançant el mètode d'interpolació, que pot integrar-se al sistema de model turboalimentat complet del motor turbo, per calcular el cabal de massa real a través de les vàlvules de connexió de desguàs i desplaçament. Finalment, els models s'han validat completament combinant-los amb un programari de modelatge unidimensional que simula tant el suport de gas com el motor sencer. D'una banda, els resultats de les validacions de l'estand de gas demostren que el model és capaç de predir bé totes les variables de flux constant. D'altra banda, els resultats de validació del motor complet demostren que el model és capaç de produir totes les variables del motor de càrrega completa, com ara el flux de massa d'aire i el pare de fre d'una bona manera amb les dades experimentals.Samala, V. (2020). Experimental characterization and mean line modelling of twin-entry and dual-volute turbines working under different admission conditions with steady flow [Tesis doctoral no publicada]. Universitat Politècnica de València. https://doi.org/10.4995/Thesis/10251/153475TESI

A holistic methodology to correct heat transfer and bearing friction losses from hot turbocharger maps in order to obtain adiabatic efficiency of the turbomachinery

This is the author¿s version of a work that was accepted for publication in International Journal of Engine Research. Changes resulting from the publishing process, such as peer review, editing, corrections, structural formatting, and other quality control mechanisms may not be reflected in this document. Changes may have been made to this work since it was submitted for publication. A definitive version was subsequently published as https://doi.org/10.1177/1468087419834194[EN] Turbocharger performance maps provided by manufacturers are usually far from the assumption of reproducing the isentropic performance. The reason being, those maps are usually measured using a hot gas stand. The definition of the effective turbocharger efficiency maps include the mechanical losses and heat transfer that has occurred during the gas stand test for the turbine maps and only the heat transfer for the compressor maps. Thus, a turbocharger engine model that uses these maps provides accurate results only when simulating turbocharger operative conditions similar to those at which the maps are recorded. However, for some critical situations such as Worldwide harmonized Light vehicles Test Cycles (WLTC) driving cycle or off-design conditions, it is difficult to ensure this assumption. In this article, an internal and external heat transfer model combined with mechanical losses model, both previously developed and calibrated, has been used as an original tool to ascertain a calculation procedure to obtain adiabatic maps from diabatic standard turbocharger maps. The turbocharger working operative conditions at the time of map measurements and geometrical information of the turbocharger are necessary to discount both effects precisely. However, the maps from turbocharger manufacturers do not include all required information. These create additional challenges to develop the procedure to obtain approximated adiabatic maps making some assumptions based on SAE standards for non-available data. A sensitivity study has been included in this article to check the validity of the hypothesis proposed by changing the values of parameters which are not included in the map data. The proposed procedure becomes a valuable tool either for Original Equipment Manufacturers (OEMs) to parameterize turbocharger performance accurately for benchmarking and turbocharged engine design or to turbocharger manufacturers to provide much-appreciated information of their performance maps.The author(s) disclosed receipt of the following financial support for the research, authorship and/or publication of this article: This work has been partially supported by FEDER and the Government of Spain through Grant No. TRA2016-79185-R.Serrano, J.; Olmeda, P.; Arnau Martínez, FJ.; Samala, V. (2020). A holistic methodology to correct heat transfer and bearing friction losses from hot turbocharger maps in order to obtain adiabatic efficiency of the turbomachinery. International Journal of Engine Research. 21(8):1314-1335. https://doi.org/10.1177/1468087419834194S13141335218Sirakov, B., & Casey, M. (2012). Evaluation of Heat Transfer Effects on Turbocharger Performance. Journal of Turbomachinery, 135(2). doi:10.1115/1.4006608Payri, F., Serrano, J. R., Fajardo, P., Reyes-Belmonte, M. A., & Gozalbo-Belles, R. (2012). A physically based methodology to extrapolate performance maps of radial turbines. Energy Conversion and Management, 55, 149-163. doi:10.1016/j.enconman.2011.11.003Chesse, P., Chalet, D., & Tauzia, X. (2011). Impact of the Heat Transfer on the Performance Calculations of Automotive Turbocharger Compressor. Oil & Gas Science and Technology – Revue d’IFP Energies nouvelles, 66(5), 791-800. doi:10.2516/ogst/2011129Serrano, J. R., Olmeda, P., Arnau, F. J., Reyes-Belmonte, M. A., & Tartoussi, H. (2015). A study on the internal convection in small turbochargers. Proposal of heat transfer convective coefficients. Applied Thermal Engineering, 89, 587-599. doi:10.1016/j.applthermaleng.2015.06.053Tanda, G., Marelli, S., Marmorato, G., & Capobianco, M. (2017). An experimental investigation of internal heat transfer in an automotive turbocharger compressor. Applied Energy, 193, 531-539. doi:10.1016/j.apenergy.2017.02.053Serrano, J., Olmeda, P., Arnau, F., & Dombrovsky, A. (2014). General Procedure for the Determination of Heat Transfer Properties in Small Automotive Turbochargers. SAE International Journal of Engines, 8(1), 30-41. doi:10.4271/2014-01-2857Payri, F., Olmeda, P., Arnau, F. J., Dombrovsky, A., & Smith, L. (2014). External heat losses in small turbochargers: Model and experiments. Energy, 71, 534-546. doi:10.1016/j.energy.2014.04.096Serrano, J. R., Olmeda, P., Tiseira, A., García-Cuevas, L. M., & Lefebvre, A. (2013). Theoretical and experimental study of mechanical losses in automotive turbochargers. Energy, 55, 888-898. doi:10.1016/j.energy.2013.04.042SAE International. Turbocharger gas stand test code, SAE J1826. Technical Report, Society of Automotive Engineers Inc, Warrendale, PA, 1995.SAE International. Supercharger testing standard, SAE J1723. Technical Report, Society of Automotive Engineers Inc, Warrendale, PA, 1995.Serrano, J. R., Olmeda, P., Páez, A., & Vidal, F. (2010). An experimental procedure to determine heat transfer properties of turbochargers. Measurement Science and Technology, 21(3), 035109. doi:10.1088/0957-0233/21/3/03510

A Robust Adiabatic Model for a Quasi-Steady Prediction of Far-Off Non-Measured Performance in Vaneless Twin-Entry or Dual-Volute Radial Turbines

[EN] The current investigation describes in detail a mass flow oriented model for extrapolation of reduced mass flow and adiabatic efficiency of double entry radial inflow turbines under any unequal and partial flow admission conditions. The model is based on a novel approach, which proposes assimilating double entry turbines to two variable geometry turbines (VGTs) using the mass flow ratio ( MFR ) between the two entries as the discriminating parameter. With such an innovative approach, the model can extrapolate performance parameters to non-measured MFR s, blade-to-jet speed ratios, and reduced speeds. Therefore, the model can be used in a quasi-steady method for predicting double entry turbines performance instantaneously. The model was validated against a dataset from two different double entry turbine types: a twin-entry symmetrical turbine and a dual-volute asymmetrical turbine. Both were tested under steady flow conditions. The proposed model showed accurate results and a coherent set of fitting parameters with physical meaning, as discussed in this paper. The obtained parameters showed very similar figures for the aforementioned turbine types, which allows concluding that they are an adequate set of values for initializing the fitting procedure of any type of double entry radial turbine.Vishnu Samala is partially supported through contract FPI-2017-S2-1256 of Programa de Apoyo para la Investigacion y Desarrollo (PAID) of Universitat Politecnica de Valencia. This work was partially funded by the 'Ayuda a Primeros Proyectos de Investigacion' (PAID-06-18), Vicerrectorado de Investigacion, Innovacion y Transferencia de la Universitat Politecnica de Valencia (UPV), Valencia, Spain.Serrano, J.; Arnau Martínez, FJ.; García-Cuevas González, LM.; Samala, V. (2020). A Robust Adiabatic Model for a Quasi-Steady Prediction of Far-Off Non-Measured Performance in Vaneless Twin-Entry or Dual-Volute Radial Turbines. 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Turbocharger turbine rotor tip leakage loss and mass flow model valid up to extreme off-design conditions with high blade to jet speed ratio. Energy, 147, 1299-1310. doi:10.1016/j.energy.2018.01.083Serrano, J. R., Olmeda, P., Arnau, F. J., & Samala, V. (2019). A holistic methodology to correct heat transfer and bearing friction losses from hot turbocharger maps in order to obtain adiabatic efficiency of the turbomachinery. International Journal of Engine Research, 21(8), 1314-1335. doi:10.1177/1468087419834194Harrell, F. E. (2001). Ordinal Logistic Regression. Springer Series in Statistics, 331-343. doi:10.1007/978-1-4757-3462-1_1

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

[EN] 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.Vishnu Samala is partially supported through contract FPI-2017-S2-1256 of Programa de Apoyo para la Investigacion y Desarrollo (PAID) of Universitat Politecnica de Valencia. This work was partially funded by FEDER and Government of Spain through Project TRA2016-79185-R. The authors wish to thank M.A. Ortiz and R. Carrascosa for their invaluable work during the experimental setup and campaign.Serrano, J.; Arnau Martínez, FJ.; García-Cuevas González, LM.; Samala, V.; Smith, L. (2019). Experimental approach for the characterization and performance analysis of twin entry radial-inflow turbines in a gas stand and with different flow admission conditions. Applied Thermal Engineering. 159:1-14. https://doi.org/10.1016/j.applthermaleng.2019.113737S11415

Experimental procedure for the characterization of turbocharger s waste-gate discharge coefficient

[EN] Nowadays, the turbocharger has become one of the key components for automotive spark-ignition engine improvements (fed with both liquid and gaseous fuels), as a support for the boosting and downsizing concept to reduce fuel consumption and exhaust emission. In gasoline engines, the usage of the waste-gate valve typically regulates the maximum boost pressure in the turbocharger system, to protect the engine and the turbocharger at high engine speeds. To improve the transient response at low engine speeds two-stage turbocharger is widely used. Two-stage systems are composed of several valves to regulate the flow to control the boosting of the system. Like, a by-pass valve between the turbines, a check valve between the compressor and a waste-gate valve for the low-pressure turbines. This paper deals with a methodology for characterizing the discharge coefficient of an electronic waste-gate valve in the turbocharger. To estimate the gas flow over the same in one-dimensional models, an empirical model is correlated and validated. For this, a constant stream experimental work has been carried out on a test rig at different valve position openings, with high turbine inlet temperatures. Finally, an optimal MAP of discharge coefficient has been drawn out through interpolation method, which can integrate into the full one-dimensional turbocharged engine model system, to calculate the actual mass flow through the waste-gate valve.The author(s) disclosed receipt of the following financial support for the research, authorship, and/or publication of this article: This work was partially funded by FEDER and Government of Spain through Project TRA2016-79185-R.Serrano, J.; Arnau Martínez, FJ.; Tiseira ., AO.; Samala, V. (2017). Experimental procedure for the characterization of turbocharger s waste-gate discharge coefficient. Advances in Mechanical Engineering. 9(10):1-9. https://doi.org/10.1177/1687814017728242S1991

Análisis térmico y fluido-dinámico de un turbogrupo ensayado y modelado con flujo a 1000ºC aguas arriba de su turbina de doble entrada

In the TFM the test of a turbocharger with double entry turbine in real conditions of operation, as for the temperature at the entrance of the turbine, will be realized. The turbine is double-entry, typical of the spark ignition engines, and will be tested at 1000ºC. It will also be carried out its thermal carazterization in an oil bank to determine the conductive properties of its components. Fluid-dynamic carazterization of the waste-gate valve will also be done. Following, a thermal and fluid dynamic modeling of the entire turbogroup will be carried out in both stationary and transient conditions. Finally the thermal balance in the turbine with the model adjusted to the experiments will be analyzed.En el TFM se realizará el ensayo de un turbogrupo con turbina de doble entrada en condiciones reales de operación en cuanto a la temperatura a la entrada de la turbina. La turbina es de doble entrada, típica de los motores de encendido provocado, y será ensayada a 1000ºC. Se realizará además su carazterización térmica en banco de aceite para determinar las propiedades conductivas de sus componentes. También se hará una carazterización fluidodinámica de la válvula de alivio de gases de escape o 'waste-gate'.A continuación, se realizará un modelado termico y fluidodinámico de todo el turbogrupo tanto en condiciones estacionarias como transitorias. Finalmente se analizará el balance térmico en la turbina con el modelo ajustado a los experimentos.Samala, V. (2017). Análisis térmico y fluido-dinámico de un turbogrupo ensayado y modelado con flujo a 1000ºC aguas arriba de su turbina de doble entrada. http://hdl.handle.net/10251/85831TFG

Evaluation of a Double-Entry Turbine Model Coupled With a One-Dimensional Calibrated Engine Model at Engine Full Load Curves

[EN] Turbocharging is one of the foremost ways of engine downsizing and represents the leading technology for reducing the engine CO2 emission standards in gasoline engine application. Turbocharger turbine always faces high unsteadiness of flow coming from the reciprocating internal combustion engines. Besides, increasing levels of engine downsizing include rising degrees of pulse charging. Utilization of pulse energy in the engine exhaust and reducing the interferences between the cylinders using the double-entry turbines is a vital element in solving the low-end-torque targets and improving rated power in highly boosted four-cylinder engines. The present paper describes a model of double-entry turbines. The model' aim is to accommodate an efficient boundary condition to turbocharged engine models with zero and one-dimensional gas dynamic codes. The model is based on the simple procedure of testing and systematizing the performance maps of these turbines with different flow admission conditions. However, the described model in the present paper is capable of extrapolating operating conditions that differ from those included in the turbine maps because a turbocharger turbine with an engine usually works instantaneously and away from the narrow range of data that are measured in the gas stand. The described model has been implemented in a one-dimensional gas dynamic code and has been used to calculate unsteady operating conditions coming from the engine. The results obtained from the whole engine simulation show that the model can produce all the full load engine variables such as air mass flow and brake torque in a reasonable degree of agreement with the experimental data that are obtained from the engine test bench.VS was partially supported through post-doctoral contract 2020-UPV-SUB.2-12450 of Science, Technology and Innovation in research structures of Universitat Politecnica de-Valencia (UPV).Galindo, J.; Serrano, J.; De La Morena, J.; Samala, V.; Guilain, S.; Batard, S. (2021). Evaluation of a Double-Entry Turbine Model Coupled With a One-Dimensional Calibrated Engine Model at Engine Full Load Curves. Frontiers in Mechanical Engineering. 6:1-24. https://doi.org/10.3389/fmech.2020.601368S124

Boosting the capabilities of gas stand data acquisition and control systems by using a digital twin based on a holistic turbocharger model

[EN] During the last decade, increasingly advanced turbocharger models have been developed for sizing, engine matching and one-dimensional modeling. This work goes further and, instead of using these models for turbocharged engines design or analysis, it implements them in the data acquisition and control system of a turbocharger gas stand. This way, interesting new capabilities arise. The paper shows that there are important synergies between advanced turbocharger gas stand data acquisition and control systems and the modern turbocharger holistic models that have not been deeply exploited until now. They can be summarized as: on-line heat fluxes analysis, in-situ outlier testing points detection, testing time saving and using digital-twin techniques to monitor turbocharger health during testing.Serrano, J.; García-Cuevas González, LM.; Samala, V.; López-Carrillo, JA.; Mai, H. (2021). Boosting the capabilities of gas stand data acquisition and control systems by using a digital twin based on a holistic turbocharger model. American Society of Mechanical Engineers (ASME). 1-16. https://doi.org/10.1115/ICEF2021-66745S11

An Experimental and Modeling Strategy for Obtaining Complete Characteristic Maps of Dual-Volute Radial Inflow Turbines

[EN] Despite the importance of turbocharged engines with dual-volute turbines, their characteristic maps and fully predictive modeling using 1D gas dynamic codes are not well established yet. The complexity of unsteady flow and the unequal admission of these turbines, when operating with pulses of engine exhaust gas, makes them a challenging system. This is mainly due to the unequal flow admission, which generates an additional degree-of-freedom with respect to well-known single entry vanned or vaneless turbines. This paper has as the main novelty a simple procedure for characterizing experimentally and elaborating characteristic maps of these turbines with unequal flow conditions. This method of analysis allows for easy interpolation within the proposed characteristic maps or conceiving simple models for calculating and extrapolating full performance parameters of dual-volute turbines. Two innovative 0D mean-line models are described that require a minimum quantity of experimental data for calibrating both: the mass flow parameter model and the isentropic efficiency model. Both models are predictive either in partial or unequal flow conditions using as inputs: the mass flow ratio and the total temperature ratio between branches; the blade speed ratio and the pressure ratio in each branch. These six inputs are generally instantaneously provided by 1D gas-dynamics codes. Therefore, the novelty of the model is its ability to be used in a quasi-steady way for dual volute turbines performance prediction. This can be done instantaneously when turbines are calculated operating at turbocharged engines under pulsating and unequal flow conditions.Vishnu Samala was partially supported through post-doctoral contract 2020-UPV-SUB.2-12450, Spanish system of Science, Technology and Innovation in research structures of Universitat Politecnica de Valencia (UPV). This work was partially funded by the 'Ayuda a Primeros Proyectos de-Investigacion' (PAID-06-18), Vicerrectorado de Investigacion, Innovacion y Transferencia de la UPV, Valencia, Spain. The authors wish to thank M.A. Ortiz and R. Carrascosa for their invaluable work during the experimental setup and testing campaign.Serrano, J.; Arnau Martínez, FJ.; García-Cuevas González, LM.; Samala, V.; Guilain, S.; Batard, S. (2021). An Experimental and Modeling Strategy for Obtaining Complete Characteristic Maps of Dual-Volute Radial Inflow Turbines. Journal of Engineering for Gas Turbines and Power. 143(7):1-10. https://doi.org/10.1115/1.4049488S110143