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

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/10.1177/1468087419869157[EN] This article presents the experimental validation of a complete integrated one-dimensional twin-scroll turbine model able to be used in reciprocating internal combustion engine unsteady simulations. A passenger car with a twin-entry-type turbine has been tested under engine-like pulse conditions by means of a specifically built gas stand. To obtain high-resolution quality data, the turbine and turbine line pipes have been instrumented with mean and instantaneous pressure sensors as well as temperature and mass flow sensors, employing a uniquely designed rotating valve for the pulse generation. This experimental configuration enables to obtain the pressure decomposition in both inlets and outlets of the turbine. Using the experimental data obtained, the model is fully validated, with special focus on the reflected and transmitted components for analysing the performance of the model and its non-linear acoustics prediction capabilities. The model presents a very high degree of correlation with the experimental results, providing a range of errors similar to the uncertainty of the measurements, even in the medium- and high-frequency spectra.The author(s) disclosed receipt of the following financial support for the research, authorship and/or publication of this article: This work was 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. P.S. was partially supported through contract FPI-2017-S2-1428 of Programa de Apoyo para la Investigacion y Desarrollo (PAID) of Universitat Politecnica de Valencia.Serrano, J.; Arnau Martínez, FJ.; García-Cuevas González, LM.; Soler-Blanco, P.; Cheung, R. (2021). Experimental validation of a one-dimensional twin-entry radial turbine model under non-linear pulse conditions. International Journal of Engine Research. 22(2):390-406. https://doi.org/10.1177/1468087419869157S390406222Watson, N., & Janota, M. S. (1982). Turbocharging the Internal Combustion Engine. doi:10.1007/978-1-349-04024-7Galindo, 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.2012.09.013Torregrosa, A. J., Broatch, A., Navarro, R., & García-Tíscar, J. (2014). Acoustic characterization of automotive turbocompressors. International Journal of Engine Research, 16(1), 31-37. doi:10.1177/1468087414562866Serrano, J. R., Tiseira, A., García-Cuevas, L. M., Inhestern, L. B., & Tartoussi, H. (2017). Radial turbine performance measurement under extreme off-design conditions. Energy, 125, 72-84. doi:10.1016/j.energy.2017.02.118Piscaglia, F., Onorati, A., Marelli, S., & Capobianco, M. (2018). A detailed one-dimensional model to predict the unsteady behavior of turbocharger turbines for internal combustion engine applications. International Journal of Engine Research, 20(3), 327-349. doi:10.1177/1468087417752525Galindo, J., Arnau, F. J., García-Cuevas, L. M., & Soler, P. (2018). Experimental validation of a quasi-two-dimensional radial turbine model. International Journal of Engine Research, 21(6), 915-926. doi:10.1177/1468087418788502Rajoo, S., Romagnoli, A., & Martinez-Botas, R. F. (2012). Unsteady performance analysis of a twin-entry variable geometry turbocharger turbine. Energy, 38(1), 176-189. doi:10.1016/j.energy.2011.12.017Rajoo, S., & Martinez-Botas, R. (2008). Variable Geometry Mixed Flow Turbine for Turbochargers: An Experimental Study. International Journal of Fluid Machinery and Systems, 1(1), 155-168. doi:10.5293/ijfms.2008.1.1.155Copeland, C. D., Martinez-Botas, R., & Seiler, M. (2010). Comparison Between Steady and Unsteady Double-Entry Turbine Performance Using the Quasi-Steady Assumption. Journal of Turbomachinery, 133(3). doi:10.1115/1.4000580Copeland, C. D., Martinez-Botas, R., & Seiler, M. (2011). Unsteady Performance of a Double Entry Turbocharger Turbine With a Comparison to Steady Flow Conditions. Journal of Turbomachinery, 134(2). doi:10.1115/1.4003171Costall, A. W., McDavid, R. M., Martinez-Botas, R. F., & Baines, N. C. (2010). Pulse Performance Modeling of a Twin Entry Turbocharger Turbine Under Full and Unequal Admission. Journal of Turbomachinery, 133(2). doi:10.1115/1.4000566Yang, M., Martinez-Botas, R., Rajoo, S., Yokoyama, T., & Ibaraki, S. (2015). An investigation of volute cross-sectional shape on turbocharger turbine under pulsating conditions in internal combustion engine. Energy Conversion and Management, 105, 167-177. doi:10.1016/j.enconman.2015.06.038Copeland, C. D., Newton, P. J., Martinez-Botas, R., & Seiler, M. (2011). The Effect of Unequal Admission on the Performance and Loss Generation in a Double-Entry Turbocharger Turbine. Journal of Turbomachinery, 134(2). doi:10.1115/1.4003226Cerdoun, M., & Ghenaiet, A. (2018). Unsteady behaviour of a twin entry radial turbine under engine like inlet flow conditions. Applied Thermal Engineering, 130, 93-111. doi:10.1016/j.applthermaleng.2017.11.001Payri, F., Benajes, J., & Reyes, M. (1996). Modelling of supercharger turbines in internal-combustion engines. International Journal of Mechanical Sciences, 38(8-9), 853-869. doi:10.1016/0020-7403(95)00105-0Chiong, M. S., Rajoo, S., Martinez-Botas, R. F., & Costall, A. W. (2012). Engine turbocharger performance prediction: One-dimensional modeling of a twin entry turbine. Energy Conversion and Management, 57, 68-78. doi:10.1016/j.enconman.2011.12.001Chiong, M. S., Rajoo, S., Romagnoli, A., Costall, A. W., & Martinez-Botas, R. F. (2016). One-dimensional pulse-flow modeling of a twin-scroll turbine. Energy, 115, 1291-1304. doi:10.1016/j.energy.2016.09.041Galindo, 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:10.1177/1468087418754899Payri, 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., Arnau, F. J., Dombrovsky, A., & Smith, L. (2015). Turbocharger heat transfer and mechanical losses influence in predicting engines performance by using one-dimensional simulation codes. Energy, 86, 204-218. doi:10.1016/j.energy.2015.03.130Gil, A., Tiseira, A. O., García-Cuevas, L. M., Usaquén, T. R., & Mijotte, G. (2018). Fast three-dimensional heat transfer model for computing internal temperatures in the bearing housing of automotive turbochargers. International Journal of Engine Research, 21(8), 1286-1297. doi:10.1177/1468087418804949Serrano, 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.2013.04.042Piñero, G., Vergara, L., Desantes, J. M., & Broatch, A. (2000). Estimation of velocity fluctuation in internal combustion engine exhaust systems through beamforming techniques. Measurement Science and Technology, 11(11), 1585-1595. doi:10.1088/0957-0233/11/11/307Zimmermann, R., Baar, R., & Biet, C. (2016). Determination of the isentropic turbine efficiency due to adiabatic measurements and the validation of the conditions via a new criterion. Proceedings of the Institution of Mechanical Engineers, Part C: Journal of Mechanical Engineering Science, 232(24), 4485-4494. doi:10.1177/0954406216670683Serrano, J. R., Arnau, F. J., Gracía-Cuevas, L. M., 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, 113737. doi:10.1016/j.applthermaleng.2019.113737Serrano, 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:10.1088/0957-0233/21/3/035109Serrano, J. R., Arnau, F. J., Dolz, V., Tiseira, A., & Cervelló, C. (2008). A model of turbocharger radial turbines appropriate to be used in zero- and one-dimensional gas dynamics codes for internal combustion engines modelling. Energy Conversion and Management, 49(12), 3729-3745. doi:10.1016/j.enconman.2008.06.031Serrano, J. R., Arnau, F. J., Fajardo, P., Reyes Belmonte, M. A., & Vidal, F. (2012). Contribution to the Modeling and Understanding of Cold Pulsating Flow Influence in the Efficiency of Small Radial Turbines for Turbochargers. Journal of Engineering for Gas Turbines and Power, 134(10). doi:10.1115/1.4007027Serrano, 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.2016.09.032Chen, H., Hakeem, I., & Martinez-Botas, R. F. (1996). Modelling of a Turbocharger Turbine Under Pulsating Inlet Conditions. Proceedings of the Institution of Mechanical Engineers, Part A: Journal of Power and Energy, 210(5), 397-408. doi:10.1243/pime_proc_1996_210_063_02Galindo, J., Serrano, J. R., Arnau, F. J., & Piqueras, P. (2009). Description of a Semi-Independent Time Discretization Methodology for a One-Dimensional Gas Dynamics Model. Journal of Engineering for Gas Turbines and Power, 131(3). doi:10.1115/1.2983015Van Leer, B. (1974). Towards the ultimate conservative difference scheme. II. Monotonicity and conservation combined in a second-order scheme. Journal of Computational Physics, 14(4), 361-370. doi:10.1016/0021-9991(74)90019-9Toro, 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/bf01414629Courant, R., Friedrichs, K., & Lewy, H. (1928). �ber die partiellen Differenzengleichungen der mathematischen Physik. Mathematische Annalen, 100(1), 32-74. doi:10.1007/bf01448839Harris, F. J. (1978). On the use of windows for harmonic analysis with the discrete Fourier transform. Proceedings of the IEEE, 66(1), 51-83. doi:10.1109/proc.1978.10837Welch, P. (1967). The use of fast Fourier transform for the estimation of power spectra: A method based on time averaging over short, modified periodograms. IEEE Transactions on Audio and Electroacoustics, 15(2), 70-73. doi:10.1109/tau.1967.116190

Common Phenolic Metabolites of Flavonoids, but Not Their Unmetabolized Precursors, Reduce the Secretion of Vascular Cellular Adhesion Molecules by Human Endothelial Cells

Background: Flavonoids have been implicated in the prevention of cardiovascular disease; however, their mechanisms of action have yet to be elucidated, possibly because most previous in vitro studies have used supraphysiological concentrations of unmetabolized flavonoids, overlooking their more bioavailable phenolic metabolites. Objective: We aimed to explore the effects of phenolic metabolites and their precursor flavonoids at physiologically achievable concentrations, in isolation and combination, on soluble vascular cellular adhesion molecule-1 (sVCAM-1). Method: Fourteen phenolic acid metabolites and 6 flavonoids were screened at 1 μM for their relative effects on sVCAM-1 secretion by human umbilical vein endothelial cells stimulated with tumor necrosis factor alpha (TNF-α). The active metabolites were further studied for their response at different concentrations (0.01 μM–100 μM), structure-activity relationships, and effect on vascular cellular adhesion molecule (VCAM)-1 mRNA expression. In addition, the additive activity of the metabolites and flavonoids was investigated by screening 25 unique mixtures at cumulative equimolar concentrations of 1 μM. Results: Of the 20 compounds screened at 1 μM, inhibition of sVCAM-1 secretion was elicited by 4 phenolic metabolites, of which protocatechuic acid (PCA) was the most active (−17.2%, P = 0.05). Investigations into their responses at different concentrations showed that PCA significantly reduced sVCAM-1 15.2–36.5% between 1 and 100 μM, protocatechuic acid-3-sulfate and isovanillic acid reduced sVCAM-1 levels 12.2–54.7% between 10 and 100 μM, and protocatechuic acid-4-sulfate and isovanillic acid-3-glucuronide reduced sVCAM-1 secretion 27.6% and 42.8%, respectively, only at 100 μM. PCA demonstrated the strongest protein response and was therefore explored for its effect on VCAM-1 mRNA, where 78.4% inhibition was observed only after treatment with 100 μM PCA. Mixtures of the metabolites showed no activity toward sVCAM-1, suggesting no additive activity at 1 μM. Conclusions: The present findings suggest that metabolism of flavonoids increases their vascular efficacy, resulting in a diversity of structures of varying bioactivity in human endothelial cells

Application of the two-step Lax and Wendroff FCT and the CE-SE method to flow transport in wall-flow monoliths

[EN] Gas dynamic codes are computational tools applied to the analysis of air management in internal combustion engines. The governing equations in one-dimensional elements are approached assuming compressible unsteady non-homentropic flow and are commonly solved applying finite difference numerical methods. These techniques can also be applied to the calculation of flow transport in complex systems such as wallflow monoliths. These elements are characterized by alternatively plugged channels with porous walls. It filters the particulates when the flowgoes through thewall from the inlet to the outlet channels. Therefore, this process couples the solution of every pair of inlet and outlet channels. In this study, the adaptation of the two-step Lax and Wendroff method and the space-time Conservation Element and Solution Element method is performed to be applied in the solution of flow transport in wall-flow monolith channels. The influence on the prediction ability is analysed by a shock-tube test and experimental data obtained under impulsive flow conditions.This work has been partially supported by the Spanish Ministerio de Ciencia e Innovacion through grant number DPI2010-20891-C02-02.Serrano, JR.; Arnau Martínez, FJ.; Piqueras, P.; García Afonso, Ó. (2014). Application of the two-step Lax and Wendroff FCT and the CE-SE method to flow transport in wall-flow monoliths. International Journal of Computer Mathematics. 91(1):71-84. https://doi.org/10.1080/00207160.2013.783206S718491

Radial turbine sound and noise characterisation with acoustic transfer matrices by means of fast one-dimensional models

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/10.1177/1468087419889429.[EN] Estimating correctly the turbine acoustics can be valuable during the engine design stage; in fact, it can lead to a more optimised design of the silencer and aftertreatment, as well as to better prediction of the scavenging effects. However, obtaining the sound and noise emissions of radial turbocharger turbines with low computational costs can be challenging. To consider these effects in a time-efficient manner, the acoustic response of single-entry radial turbines can be characterised by means of acoustic transfer matrices that change with the operating conditions. Exploiting the different time-scales of the acoustic phenomena and the change in the operating point of the turbine, lookup tables of acoustic transfer matrices can be computed. Then, the obtained characterisation can be used in mean-value engine models. This article presents a method for generating these lookup tables by means of fast one-dimensional simulations of thoroughly validated fidelity, in terms of both acoustics and extrapolation capabilities. Due to the inherent behaviour of radial turbines, the number of computations needed to fill the lookup tables is relatively small, so the method can be used as a simple preprocessing phase before mean-value simulation campaigns.Torregrosa, AJ.; García-Cuevas González, LM.; Inhestern, LB.; Soler-Blanco, P. (2021). Radial turbine sound and noise characterisation with acoustic transfer matrices by means of fast one-dimensional models. International Journal of Engine Research. 22(4):1312-1328. https://doi.org/10.1177/1468087419889429S13121328224Broatch, A., Galindo, J., Navarro, R., & García-Tíscar, J. (2014). Methodology for experimental validation of a CFD model for predicting noise generation in centrifugal compressors. International Journal of Heat and Fluid Flow, 50, 134-144. doi:10.1016/j.ijheatfluidflow.2014.06.006Galindo, J., Tiseira, A., Navarro, R., Tarí, D., & Meano, C. M. (2017). Effect of the inlet geometry on performance, surge margin and noise emission of an automotive turbocharger compressor. Applied Thermal Engineering, 110, 875-882. doi:10.1016/j.applthermaleng.2016.08.099Peat, K. S., Torregrosa, A. J., Broatch, A., & Fernández, T. (2006). An investigation into the passive acoustic effect of the turbine in an automotive turbocharger. Journal of Sound and Vibration, 295(1-2), 60-75. doi:10.1016/j.jsv.2005.11.033Torregrosa, A., Galindo, J., Serrano, J. R., & Tiseira, A. (2009). A Procedure for the Unsteady Characterization of Turbochargers in Reciprocating Internal Combustion Engines. Fluid Machinery and Fluid Mechanics, 72-79. doi:10.1007/978-3-540-89749-1_10Torregrosa, A. J., Broatch, A., Navarro, R., & García-Tíscar, J. (2014). Acoustic characterization of automotive turbocompressors. International Journal of Engine Research, 16(1), 31-37. doi:10.1177/1468087414562866Broatch, A., Galindo, J., Navarro, R., García-Tíscar, J., Daglish, A., & Sharma, R. K. (2015). Simulations and measurements of automotive turbocharger compressor whoosh noise. Engineering Applications of Computational Fluid Mechanics, 9(1), 12-20. doi:10.1080/19942060.2015.1004788Broatch, A., Galindo, J., Navarro, R., & García-Tíscar, J. (2016). Numerical and experimental analysis of automotive turbocharger compressor aeroacoustics at different operating conditions. International Journal of Heat and Fluid Flow, 61, 245-255. doi:10.1016/j.ijheatfluidflow.2016.04.003Wallace, F. J., & Adgey, J. (1967). Paper 1: Theoretical Assessment of the Non-Steady Flow Performance of Inward Radial Flow Turbines. Proceedings of the Institution of Mechanical Engineers, Conference Proceedings, 182(8), 22-36. doi:10.1243/pime_conf_1967_182_211_02Piscaglia, F., Onorati, A., Marelli, S., & Capobianco, M. (2018). A detailed one-dimensional model to predict the unsteady behavior of turbocharger turbines for internal combustion engine applications. International Journal of Engine Research, 20(3), 327-349. doi:10.1177/1468087417752525Galindo, 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.2012.09.013Galindo, J., Tiseira, A., Fajardo, P., & García-Cuevas, L. M. (2014). Development and validation of a radial variable geometry turbine model for transient pulsating flow applications. Energy Conversion and Management, 85, 190-203. doi:10.1016/j.enconman.2014.05.072Avola, C., Copeland, C., Romagnoli, A., Burke, R., & Dimitriou, P. (2017). Attempt to correlate simulations and measurements of turbine performance under pulsating flows for automotive turbochargers. Proceedings of the Institution of Mechanical Engineers, Part D: Journal of Automobile Engineering, 233(2), 174-187. doi:10.1177/0954407017739123Galindo, J., Climent, H., Tiseira, A., & García-Cuevas, L. M. (2016). Effect of the numerical scheme resolution on quasi-2D simulation of an automotive radial turbine under highly pulsating flow. Journal of Computational and Applied Mathematics, 291, 112-126. doi:10.1016/j.cam.2015.02.025Serrano, 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.2016.09.032Galindo, 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:10.1177/1468087418754899Payri, 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., Arnau, F. J., Dombrovsky, A., & Smith, L. (2015). Turbocharger heat transfer and mechanical losses influence in predicting engines performance by using one-dimensional simulation codes. Energy, 86, 204-218. doi:10.1016/j.energy.2015.03.130Serrano, 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.2013.04.042Piñero, G., Vergara, L., Desantes, J. M., & Broatch, A. (2000). Estimation of velocity fluctuation in internal combustion engine exhaust systems through beamforming techniques. Measurement Science and Technology, 11(11), 1585-1595. doi:10.1088/0957-0233/11/11/307Galindo, J., Serrano, J. R., Arnau, F. J., & Piqueras, P. (2009). Description of a Semi-Independent Time Discretization Methodology for a One-Dimensional Gas Dynamics Model. Journal of Engineering for Gas Turbines and Power, 131(3). doi:10.1115/1.2983015Serrano, J. R., Arnau, F. J., Dolz, V., Tiseira, A., & Cervelló, C. (2008). A model of turbocharger radial turbines appropriate to be used in zero- and one-dimensional gas dynamics codes for internal combustion engines modelling. Energy Conversion and Management, 49(12), 3729-3745. doi:10.1016/j.enconman.2008.06.031Serrano, J. R., Tiseira, A., García-Cuevas, L. M., Inhestern, L. B., & Tartoussi, H. (2017). Radial turbine performance measurement under extreme off-design conditions. Energy, 125, 72-84. doi:10.1016/j.energy.2017.02.118Welch, P. (1967). The use of fast Fourier transform for the estimation of power spectra: A method based on time averaging over short, modified periodograms. IEEE Transactions on Audio and Electroacoustics, 15(2), 70-73. doi:10.1109/tau.1967.1161901Serrano, J. R., Arnau, F. J., García-Cuevas, L. M., & Inhestern, L. B. (2019). An innovative losses model for efficiency map fitting of vaneless and variable vaned radial turbines extrapolating towards extreme off-design conditions. Energy, 180, 626-639. doi:10.1016/j.energy.2019.05.062Van Leer, B. (1974). Towards the ultimate conservative difference scheme. II. Monotonicity and conservation combined in a second-order scheme. Journal of Computational Physics, 14(4), 361-370. doi:10.1016/0021-9991(74)90019-9Toro, 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/bf01414629Courant, R., Friedrichs, K., & Lewy, H. (1928). �ber die partiellen Differenzengleichungen der mathematischen Physik. Mathematische Annalen, 100(1), 32-74. doi:10.1007/bf0144883

Analysis of equations of state for polymers

AbstractIn the literature there are several studies comparing the accuracy of various models in describing the PvT behavior of polymers. However, most of these studies do not provide information about the quality of the estimated parameters or the sensitivity of the prediction of thermodynamic properties to the parameters of the equations. Furthermore, there are few studies exploring the prediction of thermal expansion and compression coefficients. Based on these observations, the objective of this study is to deepen the analysis of Tait, HH (Hartmann-Haque), MCM (modified cell model) and SHT (simplified hole theory) equations of state in predicting the PvT behavior of polymers, for both molten and solid states. The results showed that all equations of state provide an adequate description of the PvT behavior in the molten state, with low standard deviations in the estimation of parameters, adequate sensitivity of their parameters and plausible prediction of specific volume, thermal expansion and isothermal compression coefficients. In the solid state the Tait equation exhibited similar performance to the molten state, while HH showed satisfactory results for amorphous polymers and difficulty in adjusting the PvT curve for semicrystalline polymers.</p

Advanced thermodynamics for engineers

Advanced Thermodynamics for Engineers, Second Edition introduces the basic concepts of thermodynamics and applies them to a wide range of technologies. Authors Desmond Winterbone and Ali Turan also include a detailed study of combustion to show how the chemical energy in a fuel is converted into thermal energy and emissions; analyze fuel cells to give an understanding of the direct conversion of chemical energy to electrical power; and provide a study of property relationships to enable more sophisticated analyses to be made of irreversible thermodynamics, allowing for new ways of efficiently covering energy to power (e.g. solar energy, fuel cells). Worked examples are included in most of the chapters, followed by exercises with solutions. By developing thermodynamics from an explicitly equilibrium perspective and showing how all systems attempt to reach equilibrium (and the effects of these systems when they cannot), Advanced Thermodynamics for Engineers, Second Edition provides unparalleled insight into converting any form of energy into power. The theories and applications of this text are invaluable to students and professional engineers of all disciplines.Includes new chapter that introduces basic terms and concepts for a firm foundation of studyFeatures clear explanations of complex topics and avoids complicated mathematical analysisUpdated chapters with recent advances in combustion, fuel cells, and more Solutions manual will be provided for end-of-chapter problem