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Article

Zhongping Tang, Zhengwen Feng, Peng Jin, Xisheng Fu and Hua Chen

The purpose of this paper is to identify the feature of soot in diesel engine oil and provide a method to stably disperse these soots using effect additives which is…

Abstract

Purpose

The purpose of this paper is to identify the feature of soot in diesel engine oil and provide a method to stably disperse these soots using effect additives which is benefical for lubricants to pass related engine tests.

Design/methodology/approach

This paper designed experiments to investigate the dispersant type, treat level and different dispersant interactions which influence on lubricant soot-related viscosity increase. The research work developed an effective dispersant package which can well solve the soot-related viscosity increase, allowing pass Mack T-11 and Mack T-8 engine tests and demonstrated the helpfulness of using a quickly screening method developed by a steel piston diesel engine CA 6DL2-35.

Findings

The effect of dispersant treat level on the viscosity increase of the oil samples was negligible. Dispersant booster can effectively improve the soot handling ability of heavy-duty diesel engine oils (HDDEO), and the appropriate treat level of dispersant booster can help HDDEO pass Mack T-8 and Mack T-11 engine tests.

Practical implications

The test results are useful for formulators to select the appropriate dispersants or dispersant booster to develop the HDDEO packages which can meet the modern diesel engine lubrication requirements.

Originality/value

Most previous studies in this field were carried out on soot formation mechanism and soot-related wear rather than how to solve the soot-related viscosity increasing of HDDEO. This paper describes the soot dispersing requirements of different HDDEO specifications and developed an effective dispersant package which can well deal with Mack T-11 and Mack T-8E standard engine tests soot handling ability requirements.

Details

Industrial Lubrication and Tribology, vol. 69 no. 5
Type: Research Article
ISSN: 0036-8792

Keywords

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Article

Mohamed Ibrahim N.H., M. Udayakumar, Sivan Suresh, Suvanjan Bhattacharyya and Mohsen Sharifpur

This study aims to investigate the insights of soot formation such as rate of soot coagulation, rate of soot nucleation, rate of soot surface growth and soot surface…

Abstract

Purpose

This study aims to investigate the insights of soot formation such as rate of soot coagulation, rate of soot nucleation, rate of soot surface growth and soot surface oxidation in ethylene/hydrogen/nitrogen diffusion jet flame at standard atmospheric conditions, which is very challenging to capture even with highly sophisticated measuring systems such as Laser Induced Incandescence and Planar laser-induced fluorescence. The study also aims to investigate the volume of soot in the flame using soot volume fraction and to understand the global correlation effect in the formation of soot in ethylene/hydrogen/nitrogen diffusion jet flame.

Design/methodology/approach

A large eddy simulation (LES) was performed using box filtered subgrid-scale tensor. A filtered and residual component of the governing equations such as continuity, momentum, energy and species are resolved and modeled, respectively. All the filtered and residual components are numerically solved using the ILU method by considering PISO pressure–velocity solver. All the hyperbolic flux uses the QUICK algorithm, and an elliptic flux uses SOU to evaluate face values. In all the cases, Courant–Friedrichs–Lewy (CFL) conditions are maintained unity.

Findings

The findings are as follows: soot volume fraction (SVF) as a function of a flame-normalized length for three different Reynolds number configurations (Re = 15,000, Re = 8,000 and Re = 5,000) using LES; soot gas phase and particulate phase insights such as rate of soot nucleation, rate of soot coagulation, rate of soot surface growth and soot surface oxidation for three different Reynolds number configurations (Re = 15,000, Re = 8,000 and Re = 5,000); and soot global correction using total soot volume in the flame volume as a function of Reynolds number and Froude number.

Originality/value

The originality of this study includes the following: coupling LES turbulent model with chemical equilibrium diffusion combustion conjunction with semi-empirical Brookes Moss Hall (BMH) soot model by choosing C6H6 as a soot precursor kinetic pathway; insights of soot formations such as rate of soot nucleation, soot coagulation rate, soot surface growth rate and soot oxidation rate for ethylene/hydrogen/nitrogen co-flow flame; and SVF and its insights study for three inlet fuel port configurations having the three different Reynolds number (Re = 15,000, Re = 8,000 and Re = 5,000).

Details

International Journal of Numerical Methods for Heat & Fluid Flow, vol. ahead-of-print no. ahead-of-print
Type: Research Article
ISSN: 0961-5539

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Article

G.H. Yeoh, R.K.K. Yuen, E.W.M. Lee and S.C.P. Chueng

This paper presents a comparison of numerical predictions employing a Computational Fluid Dynamics fire model against a series of turbulent buoyant fire experiments…

Abstract

This paper presents a comparison of numerical predictions employing a Computational Fluid Dynamics fire model against a series of turbulent buoyant fire experiments recently carried out in a two‐room compartment structure by Nielsen and Fleischmann at the University of Canterbuty, New Zealand. The model incorporates turbulence, combustion, soot generation and radiation due to a fire. An evaluation of the various approaches—volumetric heat source approach or a more sophisticated handling the fire through a combustion model—is carried out. The effect of radiation due to combustion products and soot is also investigated. The model considering combustion with radiation contribution by both the combustion products and soot provides the best agreement between the predicted results and measured data. The presence of soot is seen to significantly augment the global radiation process within the two‐compartment enclosure.

Details

International Journal of Numerical Methods for Heat & Fluid Flow, vol. 12 no. 2
Type: Research Article
ISSN: 0961-5539

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Article

Zhenhua Wang, Shikui Dong, Zhihong He, Lei Wang, Weihua Yang and Bengt Ake Sunden

H2O, CO2 and CO are three main species in combustion systems which have high volume fractions. In addition, soot has strong absorption in the infrared band. Thus, H2O, CO2

Abstract

Purpose

H2O, CO2 and CO are three main species in combustion systems which have high volume fractions. In addition, soot has strong absorption in the infrared band. Thus, H2O, CO2, CO and soot may take important roles in radiative heat transfer. To provide calculations with high accuracy, all of the participating media should be considered non-gray media. Thus, the purpose of this paper is to study the effect of non-gray participating gases and soot on radiative heat transfer in an inhomogeneous and non-isothermal system.

Design/methodology/approach

To solve the radiative heat transfer, the fluid flow as well as the pressure, temperature and species distributions were first computed by FLUENT. The radiative properties of the participating media are calculated by the Statistical Narrow Band correlated K-distribution (SNBCK), which is based on the database of EM2C. The calculation of soot properties is based on the Mie scattering theory and Rayleigh theory. The radiative heat transfer is calculated by the discrete ordinate method (DOM).

Findings

Using SNBCK to calculate the radiative properties and DOM to calculate the radiative heat transfer, the influence of H2O, CO2, CO and soot on radiation heat flux to the wall in combustion system was studied. The results show that the global contribution of CO to the radiation heat flux on the wall in the kerosene furnace was about 2 per cent, but that it can reach up to 15 per cent in a solid fuel gasifier. The global contribution of soot to the radiation heat flux on the wall was 32 per cent. However, the scattering of soot has a tiny influence on radiation heat flux to the wall.

Originality/value

This is the first time H2O, CO2, CO and the scattering of soot were all considered simultaneously to study the radiation heat flux in combustion systems.

Details

International Journal of Numerical Methods for Heat & Fluid Flow, vol. 27 no. 9
Type: Research Article
ISSN: 0961-5539

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Article

X.A. Cao, G.Q. Shao and K.H. Hu

The purpose of this paper is to explore the tribological properties of high-density polyethylene (HDPE) modified by carbon soot from the combustion of No. 0 diesel.

Abstract

Purpose

The purpose of this paper is to explore the tribological properties of high-density polyethylene (HDPE) modified by carbon soot from the combustion of No. 0 diesel.

Design/methodology/approach

Carbon soot is characterized using X-ray diffraction, transmission electron microscopy and scanning electronic microscopy. The tribological properties of HDPE samples with carbon soot are investigated on a materials surface tester with a ball-on-disk friction pair.

Findings

The collected carbon soot mainly comprises amorphous carbon nanoparticles of 50-100 nm in diameter. The main wear behaviours of pure HDPE include abrasive wear and plastic deformation. After adding carbon soot nanoparticles to HDPE, HDPE wear decreases. The appropriate carbon soot content is 8 per cent in HDPE under the selected testing conditions. Compared with other HDPE samples, HDPE with 8 per cent carbon soot has higher melting temperature, lower abrasive wear and better wear resistance. The lubrication of HDPE with carbon soot is due to the formation of a transferring film composed of HDPE, amorphous carbon and graphite carbon.

Originality/value

The paper reveals the HDPE modification and lubrication mechanisms by using carbon soot from the combustion of diesel. Related research can perhaps provide a potential approach for the treatment of carbon soot exhaust emission.

Details

Industrial Lubrication and Tribology, vol. 68 no. 5
Type: Research Article
ISSN: 0036-8792

Keywords

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Article

Bin Shi, Jian Hua Guo, Xing An Cao, En Zhu Hu and Kun Hong Hu

This paper aims to explore the effects of mineral diesel fuel carbon soot (MCS) and biodiesel carbon soot (BCS) on the lubrication of polyalphaolefin (PAO) and diesel fuels.

Abstract

Purpose

This paper aims to explore the effects of mineral diesel fuel carbon soot (MCS) and biodiesel carbon soot (BCS) on the lubrication of polyalphaolefin (PAO) and diesel fuels.

Design/methodology/approach

Two styles of carbon soot were prepared from the natural combustion of mineral diesel fuel oil (MDO) and biodiesel oil (BDO). Tribological tests were conducted on a high-frequency reciprocating rig. Friction surfaces were characterized using three-dimensional laser scanning confocal microscopy and Raman spectroscopy.

Findings

The addition of MCS and BCS to PAO could reduce friction in most cases. MCS had a negligible effect on the wear for contents not exceeding 1.0 per cent. By contrast, BCS exhibited a considerable negative influence on the wear resistance even at low contents. For diesel fuels, MCS reduced both friction and wear, whereas BCS substantially deteriorated the lubrication of BDO. MCS formed a Fe3O4/C composite lubricating film on the friction surface. BCS also entered the contact region, but it did not form an effective Fe3O4/C composite lubricating film.

Originality/value

This work compared MDO and BDO from a different perspective, i.e. the effects of their combustion carbon soot on the lubrication of lubricating oil and fuel oil. The significant negative effect of BCS on the lubrication of lubricating oil and BDO is a problem that could occur in the industrial application of BDO.

Details

Industrial Lubrication and Tribology, vol. 70 no. 3
Type: Research Article
ISSN: 0036-8792

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Article

G.I. Yakovlev, A. Gordina, Rostislav Drochytka, A.F. Buryanov and Olga Smirnova

The purpose of the study is regarding the development of eco-oriented technologies for obtaining the building gypsum materials with the involvement of industrial…

Abstract

Purpose

The purpose of the study is regarding the development of eco-oriented technologies for obtaining the building gypsum materials with the involvement of industrial by-products or waste.

Design/methodology/approach

The scanning electron microscopy, X-ray microanalysis and IR spectral analysis were used to study the structure of gypsum matrix. The method of comparison of modified and unmodified gypsum matrix was used. Physical modeling of gypsum matrix crystallization is used to study changes in the morphology of hydration products.

Findings

The experimental results show that the addition of technical soot into a gypsum binder leads to a change in the morphology of crystalline hydrates of calcium sulfate dihydrate. Results of the scanning electron microscopy, X-ray microanalysis and IR spectral analysis confirm the change of physical and mechanical characteristics of the gypsum binder due to the structural modification of the gypsum matrix with ultrafine carbon soot. The achieved degree of the structural modification of the gypsum matrix is compatible with the results obtained when the gypsum binder was modified with dispersions of carbon nanotubes.

Originality/value

The morphology of the crystalline hydrates of the gypsum matrix with the addition of 0.04%, 0.06% and 1% of the carbon soot is characterized by the transition of the classical needle-like structure of gypsum dihydrate to the lamellar structure of increased density. One can observe the formation of intergrowths around ultrafine carbon soot particles. The studied carbon additive can improve strength characteristics of the gypsum matrix.

Details

Smart and Sustainable Built Environment, vol. ahead-of-print no. ahead-of-print
Type: Research Article
ISSN: 2046-6099

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Article

Hongya Niu, Wei Hu, Wei Pian, Jingsen Fan and Jinxi Wang

The characteristics of fine aerosol particles were investigated at an urban site in Beijing during an atmospheric pollution accumulation process. The organics, sulfate and…

Abstract

The characteristics of fine aerosol particles were investigated at an urban site in Beijing during an atmospheric pollution accumulation process. The organics, sulfate and BC were the dominant components in fine particles in the clear air, and the concentrations of organics, sulfate, nitrate and ammonium increased during the haze formation. The mass concentrations of primary species (chloride and BC) in the clear air were similar to those in the haze. The morphology, mixing state and aging status of fine particles in the clear air were different from those in the haze. Accumulation secondary particles were detected with high frequency and accumulation secondary particles with coating were rare in all the samples. The frequency of soot particles with coating in the clear air was lower than that in the haze. The number ratio of accumulation secondary particles to soot containing particles changed from 3:1 in clear air to 2:3 in the haze. These results indicated that the number frequency of accumulation secondary particles decreased while that of the soot containing particles increased with the air pollutants accumulating. The core-shell ratio of coated soot particles ranged between 0.1–0.6 was 62% in the clear air, and 82% in the haze. The mode sizes for the core and the shell of soot particles were 0.35 μm and 0.55 μm in the clear air, and 0.35 μm and 1.0 μm in the haze, respectively. The mean diameters of the core and the shell were 0.3 μm and was 0.6 μm in the clear air, and 0.4 μm and 1.0 μm in the haze, respectively. These results indicated that with the air pollution accumulating, the frequency of accumulation secondary particles decreased while the soot containing particles increased. The aging process of soot particles was stronger in the haze, and resulted in greater hygroscopicity for soot particles in the haze.

Details

World Journal of Engineering, vol. 12 no. 1
Type: Research Article
ISSN: 1708-5284

Keywords

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Article

Ganji Prabhakar Rao, Vipin Dhyani, Deepak Kumar, V.R.K. Raju and S. Srinivasa Rao

This paper aims to present the effects of varying different operating parameters such as Start of Injection (9 to 21 deg bTDC), compression ratio (16 to 12.5), fuel…

Abstract

Purpose

This paper aims to present the effects of varying different operating parameters such as Start of Injection (9 to 21 deg bTDC), compression ratio (16 to 12.5), fuel injection pressure (400 to 1,400 bar) and exhaust gas recirculation (0 to 25 per cent) on the performance and emissions of the engine for constant engine speed of 1,600 rpm.

Design/methodology/approach

Simulation results were validated with experimental data available in the literature for baseline configuration. The effect of each parameter on the performance characteristics such as pressure and temperature, emission characteristics such as NOx and soot are presented and discussed. Optimization has been carried out based on the regression equations developed from the simulation results to obtain the optimum set of the parameters to achieve the desired performance and emissions. Numerical simulations have been performed for the optimized set and compared with the reference engine.

Findings

Results of optimization showed that there was a simultaneous reduction in NOx and soot while maintaining the same level of performance as that of the baseline case.

Originality/value

Based on the present work, it can be said that lesser emissions are achieved in terms of NOx and soot while maintaining the same performance in terms of peak pressure.

Details

World Journal of Engineering, vol. 13 no. 4
Type: Research Article
ISSN: 1708-5284

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Article

Jun Fu, Jianxing Li, Wei Chen, Zengfeng Zhang, Hong Mao and Yuan Tang

The purpose of this paper is to present experimental studies on the designed muffler which contains ceramic foam and has the integration function of purification and noise…

Abstract

Purpose

The purpose of this paper is to present experimental studies on the designed muffler which contains ceramic foam and has the integration function of purification and noise elimination.

Design/methodology/approach

Comparative tests were done on a diesel engine with no muffler, the original muffler and the purification muffler. The soot index (light absorption coefficient), A-weighted sound pressure level and fuel consumption rate, which were collected by the partial flow opacity method, the insertion loss measurement of spatial five points and the load characteristics tests, respectively, and the effects of purification and noise elimination were studied.

Findings

The results of this paper state that the purification muffler shows great improvement on exhaust soot purification and noise elimination. The variation in diesel fuel consumption rate was small, the sound pressure level of purification muffler was reduced by 6 to 10 dB, the insertion loss of the purification muffler was increased by 6.41 dB and the average light absorption coefficient decreased by 57.8 percent compared with the original muffler.

Originality/value

The value of this study is that it supplies a purification muffler which contains a ceramic foam. Under the prerequisite of little effect on the fuel economy of diesel engine, the purification muffler shows great improvement in exhaust soot purification and noise elimination.

Details

Multidiscipline Modeling in Materials and Structures, vol. 12 no. 4
Type: Research Article
ISSN: 1573-6105

Keywords

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