Experiments and Modelling of Automotive Turbochargers under Unsteady Conditions

The current global scenario, in which an ever increasing population with an ever growing transportation needs is coupled with a reduction in the fossil fuel production and increasing human-made pollution derived problems, leads automotive engine manufacturers to constant struggles for fuel consumption and emission reductions while keeping engine performance. One-dimensional simulation codes have become a key tool towards these objectives, but require continued accuracy refinements. Phenomena that were previously thought of a limited importance and could be extremely easily modelled now require the development of new methods to be accounted for. Among these phenomena are the turbocharger mechanical losses and the turbine behaviour under highly pulsating boundary conditions. This work is focused on the improvement of current one-dimensional models, for both mechanical losses prediction and high frequency pulsating flow turbine performance. After reviewing the state-of-the-art in experimental measurement and fast simulation of automotive turbochargers, this work presents first a experimental study of several turbochargers working under both steady-state and unsteady operating conditions, focusing on the general performance of the turbine and the losses in the power transmission between it and the compressor, even including internal pressure measurements in one of the tested units. All the measurements are corrected due to heat transfer, getting the purely adiabatic behaviour. Furthermore, a CFD simulation campaign of a radial turbine has been performed, thus obtaining a detailed description of its internal behaviour under highly pulsating flow. In the light of both the experimental and CFD-simulated results, a quasi-steady mechanical losses and a quasi-bidimensional turbine model have been developed. Both models have been validated using all the experimental and simulated data, proving a prediction accuracy improvements from the results of previous methods. The mechanical losses model offers a clear advantage over the usual practice of using a constant mechanical efficiency value for correcting the manufacturer’s turbocharger map, whereas the turbine model has demonstrated potential for turbine map extrapolation and has improved the instantaneous results over classic onedimensional turbine volute models for frequencies higher than 1000 Hz. Both models have been developed trying to keep a reduced computational cost, ensuring to exploit the specific characteristics of the processors where they are going to be run.García-Cuevas González, LM. (2014). Experiments and Modelling of Automotive Turbochargers under Unsteady Conditions [Tesis doctoral no publicada]. Universitat Politècnica de València. https://doi.org/10.4995/Thesis/10251/48458TESI

La producción de salud infantil en Colombia: una aproximación

En este trabajo se logra una aproximación nacional a los principales factores que inciden en la producción de salud infantil, así como a los determinantes de la demanda por insumos de salud, entre otros. Los datos para el estudio se tomaron de la Encuesta Nacional de Demografía y Salud 2005. El ejercicio econométrico se hizo instrumentando variables y estimando en dos etapas no lineales para corregir problemas de endogeneidad en los insumos. En general, se encontró que el estado de salud de largo plazo de los infantes, medido con un indicador de nutrición (z-talla), está determinado por: i) la conducta preventiva de la madre durante el embarazo; ii) la disponibilidad de recursos dentro del hogar, y iii) características del niño como la edad y el género.Producción de salud infantil, insumos de salud, nutrición infantil, determinantes, modelo Multinomial, z-talla, economía de la salud

Twin-entry turbine losses: An analysis using CFD data

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/10.1177/14680874211007647[EN] The current paper presents a computational fluid dynamics (CFD) flow behaviour and losses analysis of twin-entry radial turbines in terms of its Mass Flow Ratio (MFR, the ratio between the flow passing through one of its intake ports and its total mass flow), focusing on the mixing phenomena in the unequal admission conditions cases. The CFD simulations are first validated with experimental data. Then, the losses mechanisms are analysed and quantified in the different parts of the twin-entry turbine in terms of the MFR value. A sudden expansion is found at the junction of both branches in the interspace between volutes and rotor for unequal and partial admission cases. Tracking the flow coming from each of the turbine intake ports, it has been observed that both flow branches do not fully mix with each other within the rotor. Another source of losses has been identified in the contact between both flow branches due to their momentum exchange that depends on the difference between both flow branches velocities. These losses have not been considered before, and they should be included in mean line loss-based models for twin-entry turbine since they are very significant for unequal admission conditions.The author(s) disclosed receipt of the following financial support for the research, authorship, and/or publication of this article: Nicolas Medina is partially supported through contract FPU17/02803 of Programa de Formacion de Profesorado Universitario of Spanish Ministerio de Ciencia, Innovacion y Universidades. This work has been partially supported 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.Galindo, J.; Serrano, J.; García-Cuevas González, LM.; Medina, N. (2022). Twin-entry turbine losses: An analysis using CFD data. International Journal of Engine Research. 23(7):1180-1200. https://doi.org/10.1177/146808742110076471180120023

Contribution to Tip Leakage Loss Modeling in Radial Turbines Based on 3D Flow Analysis and 1D Characterization

[EN] The characterization of tip leakage flow plays an important role for one-dimesional loss modeling and design in radial turbine research. Tip leakage losses can be expressed as function of fluid momentum and mass flow passing through the tip gap. Friction-driven flow and contrariwise oriented pressure gradient-driven flow are highly coupled. However, these numbers are mostly unknown and dependent on tip gap geometry and turbine running condition. Based on a commonly used definition of a non-dimensional tip leakage momentum ratio, a novel correlation has been derived. This allows a consistent characterization for variable tip gap sizes over a wide range of operating conditions. The correlation has been validated by means of CFD data with high variety in reduced speed tip gap geometry and expansion ratios. Results of the novel number show significant improvements of quantitative and qualitative results over a wide range of running conditions in comparison to existing correlations. Furthermore, correlations for tip leakage velocities, that can easily be used in one-dimensional models, have been derived. Finally, it has been demonstrated, that the influence of inlet flow momentum on the tip leakage flow can be analyzed with presented correlations.The work has been partially supported by FEDER and the Spanish Ministry of Economy and Competitiveness through grant number TRA2016-79185-R. The authors would also like to acknowledge the Research and Development Aid Program PAID-01-16 of the Universitat Politecnica de Valencia, Spain.Serrano, J.; Navarro, R.; García-Cuevas González, LM.; Inhestern, LB. (2019). Contribution to Tip Leakage Loss Modeling in Radial Turbines Based on 3D Flow Analysis and 1D Characterization. International Journal of Heat and Fluid Flow. 78. https://doi.org/10.1016/j.ijheatfluidflow.2019.108423S7

La percepción del estado de salud: una mirada a las regiones desde la encuesta de calidad de vida 2003

En este documento se estudia el impacto de un conjunto de variables sobre la percepción del estado de salud de los individuos en las regiones que establece la Encuesta Nacional de Calidad de Vida (ECV) realizada por el Departamento Administrativo Nacional de Estadísticas, DANE, en el año 2003. Las variables denotan características socioeconómicas y demográficas de las personas, características institucionales del sistema de salud y características del hogar. El ejercicio econométrico se basa en el uso de modelos Probit Ordenados para la determinación de tal impacto. El análisis por regiones sirvió para probar que existen elementos locales o regionales que hacen que el impacto de los factores que inciden en las condiciones de salud de los individuos difiera de una región a otra

Turbocharger turbine rotor tip leakage loss and mass flow model valid up to extreme off-design conditions with high blade to jet speed ratio

[EN] Due to the power consumption restriction of the turbocharger compressor, common turbine maps are rather narrow. To extrapolate them, reliable physical submodels are needed that are valid for broad ranges. Plenty of research has been done referring to tip leakage losses in axial and traditional radial turbomachinery. However, less effort has been put into the tip leakage analysis of radial turbocharger turbines, whose characteristics including high rotational speed and geometry are rather different. Commonly developed tip leakage loss models in radial turbines are mainly based on correlations with the rotational speed, while in axial turbomachinery they are mainly based on blade loading assumptions. Wide range computational fluid dynamics (CFD) data of a medium sized automotive turbine have been used to analyze tip leakage mass flow under extremely diverse running conditions. To be able to fit a model in a broad range of the map, blade loading and rotational speed have to be considered. A novel tip clearance model has been derived from the Navier Stokes Equations. The model owns a dependency on the rotational speed and the blade loading. With this approach CFD data have been fitted in a very good quality to model the tip leakage mass flow rate and tip leakage losses.The work has been partially supported by FEDER and the Spanish Ministry of Economy and Competitiveness through grant number TRA2016-79185-R.Serrano, J.; Navarro, R.; García-Cuevas González, LM.; Inhestern, LB. (2018). 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. https://doi.org/10.1016/j.energy.2018.01.083S1299131014

Improving the effective communication soft skill in higher education engineering studies: an experience through written reports

[EN] With the new paradigm of higher education, courses syllabus are not only addressed to develop the knowledge in some specific contents, but also to let the student acquire a set of the so-called transversal competences or soft skills. Amongst these, the ability of the students to communicate in an effective manner is a soft skill that will present a key role in the future careers of the students. In this paper, the experience in two courses of the Aerospace Engineering Bachelor Degree working on the effective communication through written technical reports is presented. Different enhancements have been introduced over the years, including specific sessions to present best practices for written reports, assessment using rubrics or intermediate deliveries to provide feedback to the students before they deliver the final report. The analyzed courses belong to consecutive years and are taught in both Spanish and English, which provides a wide view for understanding the impact of each feature. With the current configuration, significant improvement in the students written reports readability is obtained. Their works are more rigorous in terms of writing and format. Nevertheless, the effect of these new features on the technical content of the reports is slight. Overall, the content is transmitted by the students in a more effective manner.Carreres Talens, M.; García-Cuevas González, LM.; Martí Gómez-Aldaraví, P.; Navarro García, R. (2020). Improving the effective communication soft skill in higher education engineering studies: an experience through written reports. Editorial Universitat Politècnica de València. 219-227. https://doi.org/10.4995/INN2019.2019.10128OCS21922

Experimental assessment of the rotor outlet flow in a twin-entry radial turbine by means of Laser Doppler Anemometry

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/10.1177/14680874211034411[EN] The current paper presents the validation of some hypotheses used for developing a one-dimensional twin-entry turbine model with experimental measurements. A Laser Doppler Anemometry (LDA) technique has been used for measuring the axial Mach number and for counting the number of particles downstream of the rotor outlet. These measurements have been done for different mass flow ratio MFR and reduced turbocharger speed conditions. The flow coming from each turbine entry does not fully mix with the other within the rotor since, downstream of the rotor, they can still be differentiated. Thus, the hypothesis of studying twin-entry turbines as two separated single-entry turbines in one-dimensional models is corroborated. Moreover, the rotor outlet area corresponding to each flow branch has linear trends with the MFR value. Therefore, the rotor outlet effective area used for one-dimensional models should vary linearly with the MFR value.The author(s) disclosed receipt of the following financial support for the research, authorship, and/or publication of this article: Nicolas Medina is partially supported through contract FPU17/02803 of Programa de Formacion de Profesorado Universitario of Spanish Ministerio de Ciencia, Innovacion y Universidades.Galindo, J.; Tiseira, A.; García-Cuevas González, LM.; Medina-Tomás, N. (2022). Experimental assessment of the rotor outlet flow in a twin-entry radial turbine by means of Laser Doppler Anemometry. International Journal of Engine Research. 23(11):1864-1878. https://doi.org/10.1177/1468087421103441118641878231

Experimental approach for the analysis of the flow behaviour in the stator of a real centripetal turbine

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/10.1177/1468087420916281[EN] During normal operation, radial turbines may work in off-design conditions. Off-design conditions may be characterised by very low expansion ratios, very high expansion ratios, very low rotational speeds or very high rotational speeds. All of these cases are difficult to characterise experimentally due to high experimental uncertainties or a lack of capabilities in the system feeding pressurised air to the turbine. Also, there are two- and three-dimensional computational fluid dynamics simulations at these operating points but could not be accurate enough due to high turbulence effects, flow detachment and shock wave generation. With a lack of high-quality data, experimental or computational, to fit the reduced-order turbine models used in zero- and one-dimensional engine simulations, there are large uncertainties associated to their results in off-design conditions. This work develops an experimental facility able to characterise the internal flow of radial turbine stators in terms of pressure and velocity fields at off-design and regular working conditions. The facility consists of an upscaled model of a radial turbine volute and stator fed with air in pressure- and temperature-controlled conditions, so different sensors can be used inside it with the least amount of flow disturbance. The different restrictions considered in the design of the upscaled model are presented, and their effects in the final experimental apparatus capabilities are discussed. A preliminary comparison between computational fluid dynamics simulations and experimental data shows encouraging results.The author(s) disclosed receipt of the following financial support for the research, authorship, and/or publication of this article: This work was partly sponsored by the programme 'Ayuda a Primeros Proyectos de Investigacion (PAID-06-18), Vicerrectorado de Investigacion, Innovacion y Transferencia de la Universitat Politecnica de Valencia (UPV), Spain'. The support given to Ms N.H.G. by Universitat Politecnica de Valencia through the 'FPI-Subprograma 2' (No. FPI-2018-S2-1368) grant within the 'Programa de Apoyo para la Investigacion y Desarrollo (PAID-0118)' is gratefully acknowledged.Galindo, J.; Tiseira, A.; García-Cuevas González, LM.; Hervás-Gómez, N. (2021). Experimental approach for the analysis of the flow behaviour in the stator of a real centripetal turbine. International Journal of Engine Research. 22(6):2010-2020. https://doi.org/10.1177/1468087420916281S20102020226Tang, H., Pennycott, A., Akehurst, S., & Brace, C. J. (2014). A review of the application of variable geometry turbines to the downsized gasoline engine. International Journal of Engine Research, 16(6), 810-825. doi:10.1177/1468087414552289Payri, 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.2011.11.003Serrano, 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:10.1088/0957-0233/21/3/035109Olmeda, P., Dolz, V., Arnau, F. J., & Reyes-Belmonte, M. A. (2013). Determination of heat flows inside turbochargers by means of a one dimensional lumped model. Mathematical and Computer Modelling, 57(7-8), 1847-1852. doi:10.1016/j.mcm.2011.11.078Serrano, J., Olmeda, P., Arnau, F., Reyes-Belmonte, M., & Lefebvre, A. (2013). Importance of Heat Transfer Phenomena in Small Turbochargers for Passenger Car Applications. SAE International Journal of Engines, 6(2), 716-728. doi:10.4271/2013-01-0576Serrano, 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.2013.04.042Serrano, J. R., Olmeda, P., Tiseira, A., García-Cuevas, L. M., & Lefebvre, A. (2013). Importance of Mechanical Losses Modeling in the Performance Prediction of Radial Turbochargers under Pulsating Flow Conditions. SAE International Journal of Engines, 6(2), 729-738. doi:10.4271/2013-01-0577Galindo, J., Fajardo, P., Navarro, R., & García-Cuevas, L. M. (2013). Characterization of a radial turbocharger turbine in pulsating flow by means of CFD and its application to engine modeling. Applied Energy, 103, 116-127. doi:10.1016/j.apenergy.2012.09.013Zhang, Y., Zhang, Y., & Wu, Y. (2016). A review of rotating stall in reversible pump turbine. Proceedings of the Institution of Mechanical Engineers, Part C: Journal of Mechanical Engineering Science, 231(7), 1181-1204. doi:10.1177/0954406216640579Galindo, J., Navarro, R., García-Cuevas, L. M., Tarí, D., Tartoussi, H., & Guilain, S. (2018). A zonal approach for estimating pressure ratio at compressor extreme off-design conditions. International Journal of Engine Research, 20(4), 393-404. doi:10.1177/1468087418754899Serrano, J. R., Arnau, F. J., García-Cuevas, L. M., Dombrovsky, A., & Tartoussi, H. (2016). Development and validation of a radial turbine efficiency and mass flow model at design and off-design conditions. Energy Conversion and Management, 128, 281-293. doi:10.1016/j.enconman.2016.09.032Navarro García, R. (s. f.). A numerical approach for predicting flow-induced acoustics at near-stall conditions in an automotive turbocharger compressor. doi:10.4995/thesis/10251/44114Inhestern, L. B. (s. f.). Measurement, Simulation, and 1D-Modeling of Turbocharger Radial Turbines at Design and Extreme Off-Design Conditions. doi:10.4995/thesis/10251/119989Menter, F. R. (1994). Two-equation eddy-viscosity turbulence models for engineering applications. AIAA Journal, 32(8), 1598-1605. doi:10.2514/3.12149Menter, F. R. (1992). Influence of freestream values on k-omega turbulence model predictions. AIAA Journal, 30(6), 1657-1659. doi:10.2514/3.11115Wilcox, D. C. (1988). Reassessment of the scale-determining equation for advanced turbulence models. AIAA Journal, 26(11), 1299-1310. doi:10.2514/3.10041Simpson, A. T., Spence, S. W. T., & Watterson, J. K. (2009). A Comparison of the Flow Structures and Losses Within Vaned and Vaneless Stators for Radial Turbines. Journal of Turbomachinery, 131(3). doi:10.1115/1.298849

A Study of the Transient Response of Duct Junctions: Measurements and Gas-Dynamic Modeling with a Staggered Mesh Finite Volume Approach

[EN] Duct junctions play a major role in the operation and design of most piping systems. The objective of this paper is to establish the potential of a staggered mesh finite volume model as a way to improve the description of the effect of simple duct junctions on an otherwise one-dimensional flow system, such as the intake or exhaust of an internal combustion engine. Specific experiments have been performed in which different junctions have been characterized as a multi-port, and that have provided precise and reliable results on the propagation of pressure pulses across junctions. The results obtained have been compared to simulations performed with a staggered mesh finite volume method with different flux limiters and different meshes and, as a reference, have also been compared with the results of a more conventional pressure loss- based model. The results indicate that the staggered mesh finite volume model provides a closer description of wave dynamics, even if further work is needed to establish the optimal calculation settings.Manuel Hernandez is partially supported through contract FPI-S2-2015-1064 of Programa de Apoyo para la Investigacin y Desarrollo (PAID) of Universitat Politecnica de Valencia.Torregrosa, AJ.; Broatch, A.; García-Cuevas González, LM.; Hernández-Marco, M. (2017). A Study of the Transient Response of Duct Junctions: Measurements and Gas-Dynamic Modeling with a Staggered Mesh Finite Volume Approach. Applied Sciences. 7(5):1-25. https://doi.org/10.3390/app7050480S12575Payri, F., Reyes, E., & Galindo, J. (2000). Analysis and Modeling of the Fluid-Dynamic Effects in Branched Exhaust Junctions of ICE. Journal of Engineering for Gas Turbines and Power, 123(1), 197-203. doi:10.1115/1.1339988Tang, S. K. (2004). Sound transmission characteristics of Tee-junctions and the associated length corrections. The Journal of the Acoustical Society of America, 115(1), 218-227. doi:10.1121/1.1631830Harrison, M. F., De Soto, I., & Rubio Unzueta, P. L. (2004). A linear acoustic model for multi-cylinder IC engine intake manifolds including the effects of the intake throttle. Journal of Sound and Vibration, 278(4-5), 975-1011. doi:10.1016/j.jsv.2003.12.009Karlsson, M., & Åbom, M. (2011). Quasi-steady model of the acoustic scattering properties of a T-junction. Journal of Sound and Vibration, 330(21), 5131-5137. doi:10.1016/j.jsv.2011.05.012Karlsson, M., & Åbom, M. (2010). Aeroacoustics of T-junctions—An experimental investigation. Journal of Sound and Vibration, 329(10), 1793-1808. doi:10.1016/j.jsv.2009.11.024Corberán, J. M. (1992). A New Constant Pressure Model for N-Branch Junctions. Proceedings of the Institution of Mechanical Engineers, Part D: Journal of Automobile Engineering, 206(2), 117-123. doi:10.1243/pime_proc_1992_206_167_02Schmandt, B., & Herwig, H. (2015). The head change coefficient for branched flows: Why «losses» due to junctions can be negative. International Journal of Heat and Fluid Flow, 54, 268-275. doi:10.1016/j.ijheatfluidflow.2015.06.004Shaw, C. T., Lee, D. J., Richardson, S. H., & Pierson, S. (2000). Modelling the Effect of Plenum-Runner Interface Geometry on the Flow Through an Inlet System. SAE Technical Paper Series. doi:10.4271/2000-01-0569Pérez-García, J., Sanmiguel-Rojas, E., Hernández-Grau, J., & Viedma, A. (2006). Numerical and experimental investigations on internal compressible flow at T-type junctions. Experimental Thermal and Fluid Science, 31(1), 61-74. doi:10.1016/j.expthermflusci.2006.02.001Naeimi, H., Domiry, G., Gorji, M., Javadirad, G., & Keshavarz, M. (2011). A parametric design of compact exhaust manifold junction in heavy duty diesel engine using CFD. Thermal Science, 15(4), 1023-1033. doi:10.2298/tsci100417041nSakowitz, A., Mihaescu, M., & Fuchs, L. (2014). Turbulent flow mechanisms in mixing T-junctions by Large Eddy Simulations. International Journal of Heat and Fluid Flow, 45, 135-146. doi:10.1016/j.ijheatfluidflow.2013.06.014Bassett, M. D., Winterbone, D. E., & Pearson, R. J. (2001). Calculation of steady flow pressure loss coefficients for pipe junctions. Proceedings of the Institution of Mechanical Engineers, Part C: Journal of Mechanical Engineering Science, 215(8), 861-881. doi:10.1177/095440620121500801Hager, W. H. (1984). An Approximate Treatment of Flow in Branches and Bends. Proceedings of the Institution of Mechanical Engineers, Part C: Journal of Mechanical Engineering Science, 198(1), 63-69. doi:10.1243/pime_proc_1984_198_088_02Paul, J., Selamet, A., Miazgowicz, K. D., & Tallio, K. V. (2007). Combining Flow Losses at Circular T-Junctions Representative of Intake Plenum and Primary Runner Interface. SAE Technical Paper Series. doi:10.4271/2007-01-0649Pérez-García, J., Sanmiguel-Rojas, E., & Viedma, A. (2010). New coefficient to characterize energy losses in compressible flow at T-junctions. Applied Mathematical Modelling, 34(12), 4289-4305. doi:10.1016/j.apm.2010.05.005Wang, W., Lu, Z., Deng, K., & Qu, S. (2014). An experimental study of compressible combining flow at 45° T-junctions. Proceedings of the Institution of Mechanical Engineers, Part C: Journal of Mechanical Engineering Science, 229(9), 1600-1610. doi:10.1177/0954406214546678Peters, B., & Gosman, A. D. (1993). Numerical Simulation of Unsteady Flow in Engine Intake Manifolds. SAE Technical Paper Series. doi:10.4271/930609Bingham, J. F., & Blair, G. P. (1985). An Improved Branched Pipe Model for Multi-Cylinder Automotive Engine Calculations. Proceedings of the Institution of Mechanical Engineers, Part D: Transport Engineering, 199(1), 65-77. doi:10.1243/pime_proc_1985_199_140_01William-Louis, M. J. P., Ould-El-Hadrami, A., & Tournier, C. (1998). On the calculation of the unsteady compressible flow through an N-branch junction. Proceedings of the Institution of Mechanical Engineers, Part C: Journal of Mechanical Engineering Science, 212(1), 49-56. doi:10.1243/0954406981521033Bassett, M. D., Pearson, R. J., Fleming, N. P., & Winterbone, D. E. (2003). A Multi-Pipe Junction Model for One-Dimensional Gas-Dynamic Simulations. SAE Technical Paper Series. doi:10.4271/2003-01-0370Pearson, R. J., Bassett, M. D., Batten, P., Winterbone, D. E., & Weaver, N. W. E. (1999). Multi-Dimensional Wave Propagation in Pipe Junctions. SAE Technical Paper Series. doi:10.4271/1999-01-1186Bassett, M. D., Winterbone, D. E., & Pearson, R. J. (2000). Modelling Engines with Pulse Converted Exhaust Manifolds Using One-Dimensional Techniques. SAE Technical Paper Series. doi:10.4271/2000-01-0290Montenegro, G., Onorati, A., Piscaglia, F., & D’Errico, G. (2007). Integrated 1D-MultiD Fluid Dynamic Models for the Simulation of I.C.E. Intake and Exhaust Systems. SAE Technical Paper Series. doi:10.4271/2007-01-0495Onorati, A., Montenegro, G., D’Errico, G., & Piscaglia, F. (2010). Integrated 1D-3D Fluid Dynamic Simulation of a Turbocharged Diesel Engine with Complete Intake and Exhaust Systems. SAE Technical Paper Series. doi:10.4271/2010-01-1194Montenegro, G., Onorati, A., & Della Torre, A. (2013). The prediction of silencer acoustical performances by 1D, 1D–3D and quasi-3D non-linear approaches. Computers & Fluids, 71, 208-223. doi:10.1016/j.compfluid.2012.10.016Morel, T., Silvestri, J., Goerg, K.-A., & Jebasinski, R. (1999). Modeling of Engine Exhaust Acoustics. SAE Technical Paper Series. doi:10.4271/1999-01-1665Sapsford, S. M., Richards, V. C. M., Amlee, D. R., Morel, T., & Chappell, M. T. (1992). Exhaust System Evaluation and Design by Non-Linear Modeling. SAE Technical Paper Series. doi:10.4271/920686Montenegro, G., Della Torre, A., Onorati, A., Fairbrother, R., & Dolinar, A. (2011). Development and Application of 3D Generic Cells to the Acoustic Modelling of Exhaust Systems. SAE Technical Paper Series. doi:10.4271/2011-01-1526Payri, F., Desantes, J. M., & Broatch, A. (2000). Modified impulse method for the measurement of the frequency response of acoustic filters to weakly nonlinear transient excitations. The Journal of the Acoustical Society of America, 107(2), 731-738. doi:10.1121/1.428256Torregrosa, A. J., Broatch, A., Fernández, T., & Denia, F. D. (2006). Description and measurement of the acoustic characteristics of two-tailpipe mufflers. The Journal of the Acoustical Society of America, 119(2), 723. doi:10.1121/1.2159228Torregrosa, A. J., Broatch, A., Arnau, F. J., & Hernández, M. (2016). A non-linear quasi-3D model with Flux-Corrected-Transport for engine gas-exchange modelling. Journal of Computational and Applied Mathematics, 291, 103-111. doi:10.1016/j.cam.2015.03.034Montenegro, G., Della Torre, A., Onorati, A., & Fairbrother, R. (2013). A Nonlinear Quasi-3D Approach for the Modeling of Mufflers with Perforated Elements and Sound-Absorbing Material. Advances in Acoustics and Vibration, 2013, 1-10. doi:10.1155/2013/546120CMT—Motores Térmicos, Universitat Politècnica de Valènciahttp://www.openwam.org/Ikeda, T., & Nakagawa, T. (1979). On the SHASTA FCT Algorithm for the Equation ∂ρ ∂t + ∂ ∂x (υ(ρ)ρ) = 0. Mathematics of Computation, 33(148), 1157. doi:10.2307/2006453Toro, E. F., Spruce, M., & Speares, W. (1994). Restoration of the contact surface in the HLL-Riemann solver. Shock Waves, 4(1), 25-34. doi:10.1007/bf01414629Van Leer, B. (1979). Towards the ultimate conservative difference scheme. V. A second-order sequel to Godunov’s method. Journal of Computational Physics, 32(1), 101-136. doi:10.1016/0021-9991(79)90145-