Thermal and mutual diffusivities of fuel-related binary liquid mixtures under pre-combustion conditions

Piszko, Maximilian; Wu, Wen-Tuan; Will, Stefan; Rausch, Michael H.; Giraudet, Cédric; Fröba, Andreas P.

doi:10.1016/j.fuel.2019.01.078

Cited by 33 publications

(54 citation statements)

References 43 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…The limitation regarding the resolution of multiple hydrodynamic modes accessible by DLS is not only restricted to the supercritical state close to the vicinity of the plait critical point. It was also observed close to the consolute critical point of a ternary mixture [8,9], in the saturated liquid phase of a binary mixture at vapor-liquid equilibrium [10][11][12], and in the liquid state for binary mixtures near their plait critical point [13]. For the last two cases, this limitation was observed close to the region where thermal and Fick diffusivities match.…”

Section: Introductionmentioning

confidence: 69%

“…the experimental setup including the optical arrangement, the sample cell, the pressure and temperature control can be found in Refs. [13,24]. Before filling the pressure system, including the sample cell, an oil-sealed vacuum pump was used to lower the pressure down to about 0.4 Pa.…”

Section: Experimental Setup and Conditionsmentioning

confidence: 99%

“…After filling the mixture, it was processed close to the state of interest by means of a lubricant-free gas compressor and a spindle press. For a fine adjustment of the pressure in the sample cell as well as for pressure stabilization during the experiments, resistance heating of the expansion bellows attached to the sample cell was applied [13]. Also for the measurement cell, resistance heating was applied for temperature control.…”

Section: Experimental Setup and Conditionsmentioning

confidence: 99%

See 2 more Smart Citations

Diffusivities of an Equimolar Methane–Propane Mixture Across the Two-Phase Region by Dynamic Light Scattering

2020

Self Cite

View full text Add to dashboard Cite

The present contribution examines the accessibility of diffusivities across the twophase region of an equimolar methane-propane mixture for dynamic light scattering (DLS) experiments. Heterodyne DLS experiments and theoretical calculations of the Rayleigh ratio were performed at 125 different thermodynamic states including the gas, liquid, supercritical, and the two-phase region. The present measurements document that two diffusivities can be determined simultaneously in the liquid state and saturated liquid phase for temperatures and pressures which correspond to densities larger than 1.15 times the critical density. Based on a rigorous assignment of the signals detected in this work, the slow and fast diffusivities could be associated with the Fick and thermal diffusivities. For all other thermodynamic states, a single hydrodynamic mode or signal was obtained experimentally. With the help of theoretical Rayleigh ratios as well as from the general behavior of the diffusivities as a function of temperature and pressure, the signals were identified to be related to the Fick diffusivity in the supercritical state and to a mixed diffusivity in the gas state and the saturated vapor phase. The results are discussed in connection with the behavior of the diffusivities along certain paths in the pressure-temperature projection of the phase diagram of the mixture.

show abstract

Section: Introductionmentioning

confidence: 69%

Section: Experimental Setup and Conditionsmentioning

confidence: 99%

Section: Experimental Setup and Conditionsmentioning

confidence: 99%

See 1 more Smart Citation

Diffusivities of an Equimolar Methane–Propane Mixture Across the Two-Phase Region by Dynamic Light Scattering

2020

Self Cite

View full text Add to dashboard Cite

show abstract

“…For the characterization of particle size and its distribution as well as the dispersion stability of the nanofluids in the same fluid state as it is investigated in connection with the effective thermal conductivity, the diffusion coefficients were obtained by dynamic light scattering (DLS). For details on the principles of the technique [52] and its application for the determination of several thermophysical properties of various types of fluids [53][54][55][56] and dispersed systems [57][58][59], the reader is referred to the respective literature. In the following, only the information relevant for the present investigations is given.…”

Section: Diffusion Coefficients By Dynamic Light Scattering (Dls)mentioning

confidence: 99%

Effective Thermal Conductivity of Nanofluids: Measurement and Prediction

et al. 2020

Self Cite

View full text Add to dashboard Cite

In the present study, the effective thermal conductivity of nanoparticle dispersions, so-called nanofluids, is investigated experimentally and theoretically. For probing the influence of the nanoparticles on the effective thermal conductivity of dispersions with water as liquid continuous phase, nearly spherical and monodisperse titanium dioxide (TiO 2 ), silicon dioxide (SiO 2 ), and polystyrene (PS) nanoparticles with strongly varying thermal conductivities were used as model systems. For the measurement of the effective thermal conductivity of the nanofluids with particle volume fractions up to 0.31, a steady-state guarded parallel-plate instrument was applied successfully at temperatures between (298 and 323) K. For the same systems, dynamic light scattering (DLS) was used to analyze the collective translational diffusion, which provided information on the dispersion stability and the distribution of the particle size as essential factors for the effective thermal conductivity. The measurement results for the effective thermal conductivity show no temperature dependency and only a moderate change as a function of particle volume fraction, which is positive or negative for particles with larger or smaller thermal conductivities than the base fluid. Based on these findings, our theoretical model for the effective thermal conductivity originally developed for nanofluids containing fully dispersed particles of large thermal conductivities was revisited and also applied for a reliable prediction in the case of particles of relatively low thermal conductivities.

show abstract

“…Further information surrounding the combustion process in the engine can be obtained, for example on preheating and evaporation of the fuel streams [133] , [134] , [135] . Moreover, combustion diagnostics research is also directed to gas turbine combustors and furnaces, with ambitious techniques such as femtosecond two-photon LIF imaging of CO applied to piloted liquid spray flames [136] .…”

Section: Selected Combustion Chemistry Advances – Overview and Recentmentioning

confidence: 99%

Combustion in the future: The importance of chemistry

Kohse‐Höinghaus

2021

Proceedings of the Combustion Institute

View full text Add to dashboard Cite

Combustion involves chemical reactions that are often highly exothermic. Combustion systems utilize the energy of chemical compounds released during this reactive process for transportation, to generate electric power, or to provide heat for various applications. Chemistry and combustion are interlinked in several ways. The outcome of a combustion process in terms of its energy and material balance, regarding the delivery of useful work as well as the generation of harmful emissions, depends sensitively on the molecular nature of the respective fuel. The design of efficient, low-emission combustion processes in compliance with air quality and climate goals suggests a closer inspection of the molecular properties and reactions of conventional, bio-derived, and synthetic fuels. Information about flammability, reaction intensity, and potentially hazardous combustion by-products is important also for safety considerations. Moreover, some of the compounds that serve as fuels can assume important roles in chemical energy storage and conversion. Combustion processes can furthermore be used to synthesize materials with attractive properties. A systematic understanding of the combustion behavior thus demands chemical knowledge. Desirable information includes properties of the thermodynamic states before and after the combustion reactions and relevant details about the dynamic processes that occur during the reactive transformations from the fuel and oxidizer to the products under the given boundary conditions. Combustion systems can be described, tailored, and improved by taking chemical knowledge into account. Combining theory, experiment, model development, simulation, and a systematic analysis of uncertainties enables qualitative or even quantitative predictions for many combustion situations of practical relevance. This article can highlight only a few of the numerous investigations on chemical processes for combustion and combustion-related science and applications, with a main focus on gas-phase reaction systems. It attempts to provide a snapshot of recent progress and a guide to exciting opportunities that drive such research beyond fossil combustion.

show abstract

Thermal and mutual diffusivities of fuel-related binary liquid mixtures under pre-combustion conditions

Cited by 33 publications

References 43 publications

Diffusivities of an Equimolar Methane–Propane Mixture Across the Two-Phase Region by Dynamic Light Scattering

Diffusivities of an Equimolar Methane–Propane Mixture Across the Two-Phase Region by Dynamic Light Scattering

Effective Thermal Conductivity of Nanofluids: Measurement and Prediction

Combustion in the future: The importance of chemistry

Contact Info

Product

Resources

About