Author: Ahmet Emre Karatas Publisher: ISBN: 9780494592069 Category : Languages : en Pages : 206
Book Description
In the formation process of soot in the flames of even-carbon-numbered fuels, acetylene and its derivatives are suspected to be dominant. The addition of an odd-carbon-numbered fuel into these flames introduces methyl radicals and/or C3 chemistries, which are believed to (de)activate certain chemical pathways towards the production of soot. The resultant soot formation rate of the mixture could be higher than the sum of the respective rates of the mixture components, i.e., synergistic effect.In this work, the mixtures of butane isomers, ethylene-butane isomers, and propane-butane isomers were studied on a co-flow and a counterflow burner. Chemical effects were isolated from those of thermal and dilution by mixing isomers and comparing the mixtures including one isomer to those including the counterpart. Line of sight attenuation (LOSA) and laser-light extinction techniques were used for measuring soot volume fraction. The results provide information on synergistic effects in soot formation for the fuels used.
Author: Ahmet Emre Karatas Publisher: ISBN: Category : Languages : en Pages : 0
Book Description
In the formation process of soot in the flames of even-carbon-numbered fuels, acetylene and its derivatives are suspected to be dominant. The addition of an odd-carbon-numbered fuel into these flames introduces methyl radicals and/or C3 chemistries, which are believed to (de)activate certain chemical pathways towards the production of soot. The resultant soot formation rate of the mixture could be higher than the sum of the respective rates of the mixture components, i.e., synergistic eff ect. In this work, the mixtures of butane isomers, ethylene-butane isomers, and propane-butane isomers were studied on a co-flow and a counterflow burner. Chemical effects were isolated from those of thermal and dilution by mixing isomers and comparing the mixtures including one isomer to those including the counterpart. Line of sight attenuation (LOSA) and laser-light extinction techniques were used for measuring soot volume fraction. The results provide information on synergistic effects in soot formation for the fuels used.
Author: Margaret Kathleen Bohan Publisher: ISBN: 9780494210062 Category : Combustion Languages : en Pages : 150
Book Description
Understanding the factors that effect soot formation is essential to development of predictive models and the design of combustion processes that reduce the formation of particulates. Synergistic effects in flames of gas mixtures, increases in soot volume fraction that are higher than would be expected based on the soot volume fractions in the pure gas flames, have been observed in previous studies. The two isomers of butane were chosen to eliminate changes in flame carbon content, mass flow rate, and adiabatic flame temperature that are normally encountered when comparing flames of pure gases to flames of gas mixtures, and which also effect soot formation. A co-flow annular burner and a line-of-sight attenuation apparatus were used to produce radially-resolved soot volume fraction measurements. The experimental results give further insight into the sooting propensities of isobutane and n-butane, as well as their effect soot formation in ethylene and methane flames.
Author: Henning Bockhorn Publisher: Springer Science & Business Media ISBN: 3642851673 Category : Science Languages : en Pages : 595
Book Description
Soot Formation in Combustion represents an up-to-date overview. The contributions trace back to the 1991 Heidelberg symposium entitled "Mechanism and Models of Soot Formation" and have all been reedited by Prof. Bockhorn in close contact with the original authors. The book gives an easy introduction to the field for newcomers, and provides detailed treatments for the specialists. The following list of contents illustrates the topics under review:
Author: Paul Michael Mandatori Publisher: ISBN: 9780494160565 Category : Combustion Languages : en Pages : 198
Book Description
Ethane-air laminar coflow non-smoking diffusion flames have been studied at pressures up to 3.34 MPa to determine the effect of pressure on soot formation, flame temperatures and physical flame properties. The spectral soot emission (SSE) diagnostic was used to obtain spatially resolved (both radially and axially) soot volume fraction and soot temperature measurements at pressures of 0.20 to 3.34 MPa. In general, temperature profiles of a given height were found to decrease with increasing pressure. Pressure was found to enhance soot formation with decreased sensitivity as pressures were increased. A power law relation between maximum soot volume fraction and pressure was found to be fvmax & prop;P 2.39 for 0.20 & le; P & le; 1.52 MPa and fvmax & prop;P 1.10 for 1.52 & le; P & le; 3.34 MPa. The integrated line-of-sight soot volume fraction was found to vary as fvline, max & prop;P 2.32 for 0.20 & le; P & le; 0.51 MPa, fvline, max & prop;P 1.44 for 0.51 & le; P & le; 1.52 MPa and fvline, max & prop;P 0.95 for 1.52 & le; P & le; 3.34 MPa. The variation of maximum carbon conversion to soot, as a percentage of the fuel's carbon, was etas, max & prop; P2.23 for 0.20 & le; P & le; 1.13 MPa, etas, max & prop; P1.12 for 0.51 & le; P & le; 1.52 MPa and etas, max & prop; P0.41 for 1.52 & le; P & le; 3.34 MPa. The maximum value of carbon conversion was found to be eta s, max = 27.61% at P = 3.34 MPa.
Author: Tongfeng Zhang Publisher: ISBN: Category : Languages : en Pages :
Book Description
In the present thesis, fundamental experimental and numerical studies are performed for the soot formation of liquid fuel relevant compounds. The thesis is composed of four research studies. The first develops an improved data analysis approach for the combined laser extinction and two-angle elastic light scattering diagnostics to relate the various measured optical cross sections to soot aggregate properties. Compared to previously reported studies, the proposed approach can be applied to a wider range of soot sources by removing the assumption made to scattering regime or moment ratio of aggregate size distribution. The second study investigates the effects of n-propylbenzene addition to n-dodecane on soot formation and aggregate structure in a laminar coflow diffusion flame using the combined laser extinction and two-angle elastic light scattering method. It is shown that the relative importance of soot inception and surface growth affected by n-propylbenzene addition is different along the flame wing and centerline, with the aromatic fuel chemistry effect being stronger along the centerline. The third study extends the investigation on the same issue using a numerical model. The simulation results show that mixing n-propylbenzene into the liquid fuel mixture accelerates soot inception, and increases soot surface growth per unit surface area by PAH addition, while soot surface growth per unit surface area by HACA is shown to decrease modestly with n-propylbenzene addition. The fourth and final study investigates the soot formation from jet fuel in a laminar coflow diffusion flame using both numerical and experimental methods. The results demonstrate the robustness of the soot model to changes of fuel and also show that the HyChem model (i.e., lumped fuel breakdown approach, Xu et al., 2017) can be used to predict soot formation from real jet fuel combustion in laminar coflow diffusion flames by adding a PAH growth scheme to the model.
Author: Wasi Syed Publisher: ISBN: Category : Languages : en Pages : 0
Book Description
The effect of sooting propensity of various compositions of methane and ethanol fuel in laminar diffusion flames at elevated pressures was analyzed numerically. Simulations of laminar diffusion flames comprised of pressure conditions up to 20 atm and composition of ethanol and methane fuel ranging from pure methane to pure ethanol. For all fuel compositions evaluated, the total carbon mass flow rate was maintained at a constant value of 0.458 mg/s. Soot formation and soot yield were corroborated against measured data and demonstrated well agreement with trends for pressure and fuel composition. For elevated pressure, fuel compositions with higher ethanol content yield higher peak soot concentrations, however at lower pressures synergistic effects result to soot concentration decreasing with ethanol content for ethanol dominant fuel mixtures. Finally, the effect of conjugate heat transfer and modification in burner wall geometry were evaluated which exhibited improved trends and overall results.
Author: Ahmet Emre Karatas
Author: Ahmet Emre Karatas
Author: Margaret Kathleen Bohan
Author: Richard L. Axelbaum
Author: Guozheng Lin
Author: Henning Bockhorn
Author: Paul Michael Mandatori
Author: Tongfeng Zhang
Author: Wasi Syed
Author: eO L. Geulder