Experimental and Numerical Study on the Characteristics of Liquid Phase LPG and Diesel Fuel Sprays

2006 ◽  
Author(s):  
Xiao Helin ◽  
Zhang Yusheng ◽  
Zhang Huiya
Keyword(s):  
Liquid Phase ◽  
Diesel Fuel ◽  
Numerical Study ◽  
Fuel Sprays

Gas and liquid phase transport in pulsed fuel sprays

1996 ◽  
Author(s):  
Pete Jennings ◽  
James Drallmeier
Keyword(s):  
Liquid Phase ◽  
Fuel Sprays ◽  
Phase Transport

Infrared measurements of droplets in the dense region of diesel fuel sprays

1997 ◽  
Author(s):  
Terry Parker ◽  
Luca Rainaldi ◽  
Eric Jepsen ◽  
Terry Parker ◽  
Luca Rainaldi ◽  
...  
Keyword(s):  
Diesel Fuel ◽  
Dense Region ◽  
Fuel Sprays ◽  
Infrared Measurements

scholarly journals A numerical study of aerosol influence on mixed-phase stratiform clouds through modulation of the liquid phase

2013 ◽  
Vol 13 (4) ◽  
pp. 1733-1749 ◽  
Author(s):  
G. de Boer ◽  
T. Hashino ◽  
G. J. Tripoli ◽  
E. W. Eloranta
Keyword(s):  
Liquid Phase ◽  
Mass Fraction ◽  
Freezing Point ◽  
Numerical Study ◽  
Liquid Droplet ◽  
Number Concentration ◽  
Mixed Phase ◽  
Large Variability ◽  
Stratiform Clouds ◽  
Aerosol Properties

Abstract. Numerical simulations were carried out in a high-resolution two-dimensional framework to increase our understanding of aerosol indirect effects in mixed-phase stratiform clouds. Aerosol characteristics explored include insoluble particle type, soluble mass fraction, influence of aerosol-induced freezing point depression and influence of aerosol number concentration. Simulations were analyzed with a focus on the processes related to liquid phase microphysics, and ice formation was limited to droplet freezing. Of the aerosol properties investigated, aerosol insoluble mass type and its associated freezing efficiency was found to be most relevant to cloud lifetime. Secondary effects from aerosol soluble mass fraction and number concentration also alter cloud characteristics and lifetime. These alterations occur via various mechanisms, including changes to the amount of nucleated ice, influence on liquid phase precipitation and ice riming rates, and changes to liquid droplet nucleation and growth rates. Alteration of the aerosol properties in simulations with identical initial and boundary conditions results in large variability in simulated cloud thickness and lifetime, ranging from rapid and complete glaciation of liquid to the production of long-lived, thick stratiform mixed-phase cloud.

scholarly journals Fuel spray vapour distribution correlations for a high pressure diesel fuel spray cases for different injector nozzle geometries.

2017 ◽  
Author(s):  
Darlington Njere ◽  
Nwabueze Emekwuru
Keyword(s):  
High Pressure ◽  
Liquid Phase ◽  
Diesel Fuel ◽  
Ambient Pressure ◽  
Vapour Phase ◽  
Fuel Spray ◽  
Combustion Chambers ◽  
Complete Combustion ◽  
Fuel Injectors ◽  
Fuel Vapour

The evolution of diesel fuel injection technology, to facilitate strong correlations of in-cylinder spray propagation with injection conditions and injector geometry, is crucial in facing emission challenges. More observations of spray propagation are, therefore, required to provide valuable information on how to ensure that all the injected fuel has maximum contact with the available air, to promote complete combustion and reduce emissions. In this study, high pressure diesel fuel sprays are injected into a constant-volume chamber at injection and ambient pressure values typical of current diesel engines. For these types of sprays the maximum fuel liquid phase penetration is different and reached sooner than the maximum fuel vapour phase penetration. Thus, the vapour fuel could reach the combustion chamber wall and could be convected and deflected by swirling air. In hot combustion chambers this impingement can be acceptable but this might be less so in larger combustion chambers with cold walls. The fuel-ambient mixture in vapourized fuel spray jets is essential to the efficient performance of these engines. For this work, the fuel vapour penetration values are presented for fuel injectors of different k-factors. The results indicate that the geometry of fuel injectors based on the k-factors appear to affect the vapour phase penetration more than the liquid phase penetration. This is a consequence of the effects of the injector types on the exit velocity of the fuel droplets.DOI: http://dx.doi.org/10.4995/ILASS2017.2017.4951

VELOCITY MEASUREMENTS OF DENSE DIESEL FUEL SPRAYS IN DENSE AIR

2004 ◽  
Vol 14 (6) ◽  
pp. 589-610 ◽  
Author(s):  
H. Chaves ◽  
C. Kirmse ◽  
F. Obermeier
Keyword(s):  
Diesel Fuel ◽  
Velocity Measurements ◽  
Fuel Sprays

Three-Dimensional Numerical Study on Pool Stratification Behavior in Molten Corium-Concrete Interaction (MCCI) With MPS Method

2018 ◽  
Author(s):  
Xin Li ◽  
Ikken Sato ◽  
Akifumi Yamaji ◽  
Guangtao Duan
Keyword(s):  
Liquid Phase ◽  
Phase Change ◽  
Molten Pool ◽  
Numerical Study ◽  
Three Dimensional ◽  
Metallic Phase ◽  
Severe Accident ◽  
Mps Method ◽  
Solid Liquid ◽  
Concrete Interface

Molten corium-concrete interaction (MCCI) is an important ex-vessel phenomenon that could happen during the late phase of a hypothetical severe accident in a light water reactor. When the molten corium, which is generally comprised of UO2, ZrO2 and metals such as zircalloy and stainless steel, is discharged into a dry reactor cavity, a stratified molten pool configuration with two immiscible oxidic and metallic phases can be expected to form and lead to MCCI. Compared to a homogenous oxidic molten pool configuration, the metallic phase in the stratified molten pool might influence the crust formation on the corium-concrete interface and consequently cause different concrete ablation behavior to evaluate MCCI progression concerning containment failure. In terms of this issue, past experimental studies, such as COMET-L, VULCANO VBS and MOCKA test series, have been carried out to investigate the influence of such oxidic and metallic stratified pool configuration on MCCI. The experimental results have shown that the metallic phase can have a significant impact on the axial and radial ablation kinetics that could influence the ablation patterns of reactor pit. As regards numerical studies, past numerical modeling of MCCI was generally based on Eulerian methods and simplified empirical approach to simulate solid/liquid phase change and evolving of corium/crust/concrete interface. Such modeling might be efficient but have shown deficiencies and inadequacies due to its Eulerian and empirical nature, which has suggested a necessity to seek for a more mechanistic approach for modeling of MCCI. In this sense, Moving Particle Semi-implicit (MPS) method is considered suitable for MCCI analysis for its advantages of tracking interfaces and modeling phase change accurately as a Lagrangian particle method. In the present study, a three-dimensional (3-D) numerical study has been performed to simulate COMET-L3 test carried out by KIT with a stratified molten pool configuration of simulant materials with improved MPS method. Solid/liquid phase change was simulated with types of solid and liquid particles with thermal and physical properties including temperature and solid fraction, which enabled tracking of the solid/liquid status of each particle to achieve accurate free surface and corium/crust/concrete interface capturing. The heat transfer between corium/crust/concrete was modeled with heat conduction between particles. Moreover, the potential influence of the siliceous aggregates was also investigated by setting up two different case studies since there was previous study indicating that siliceous aggregates in siliceous concrete might contribute to different axial and radial concrete ablation rates. The simulation results have indicated that metal melt as corium in MCCI can have completely different characteristics regarding concrete ablation pattern from that of oxidic corium, which needs to be taken into consideration when assessing the containment melt-through time in severe accident management.

scholarly journals Influence of Injection Timing on Performance and Exhaust Emission of CI Engine Fuelled with Butanol-Diesel Using a 1D GT-Power Model

Processes ◽  
2019 ◽  
Vol 7 (5) ◽  
pp. 299 ◽  
Author(s):  
Salman Abdu Ahmed ◽  
Song Zhou ◽  
Yuanqing Zhu ◽  
Yongming Feng ◽  
Adil Malik ◽  
...  
Keyword(s):  
Co2 Emissions ◽  
Diesel Fuel ◽  
Numerical Study ◽  
Computational Simulation ◽  
Engine Performance ◽  
Primary Objective ◽  
Exhaust Emission ◽  
Injection Timing ◽  
Brake Mean Effective Pressure ◽  
The Impact

Injection timing variations have a significant effect on the performance and pollutant formation in diesel engines. Numerical study was conducted to investigate the impact of injection timing on engine performance and pollutants in a six-cylinder turbocharged diesel engine. Diesel fuel with different amounts (5%, 15%, and 25% by volume) of n-butanol was used. Simulations were performed at four distinct injection timings (5°, 10°, 20°, 25°CA bTDC) and two distinct loads of brake mean effective pressure (BMEP = 4.5 bar and 10.5 bar) at constant engine speed (1800 rpm) using the GT-Power computational simulation package. The primary objective of this research is to determine the optimum injection timing and optimum blending ratio for improved efficiencies and reduced emissions. Notable improvements in engine performance and pollutant trends were observed for butanol-diesel blends. The addition of butanol to diesel fuel has greatly diminished NOX and CO pollutants but it elevated HC and CO2 emissions. Retarded injection timing decreased NOX and CO2 pollutants while HC and CO2 emissions increased. The results also indicated that early injection timings (20°CA bTDC and 25°CA bTDC) lowered both CO2 and unburned hydrocarbon emissions. Moreover, advanced injection timing slightly improved brake thermal efficiency (BTE) for all engine loads. It is concluded that retarded injection timing, i.e., 10°CA bTDC demonstrated optimum results in terms of performance, combustion and emissions and among the fuels 15B showed good outcome with regard to BTE, higher heat release rate, and lower pollution of HC, CO, and NOx.

scholarly journals Liquid-liquid phase separation and viscosity within secondary organic aerosol generated from diesel fuel vapors

2019 ◽  
Author(s):  
Mijung Song ◽  
Adrian M. Maclean ◽  
Yuanzhou Huang ◽  
Natalie R. Smith ◽  
Sandra L. Blair ◽  
...  
Keyword(s):  
Phase Separation ◽  
Liquid Phase ◽  
Diesel Fuel ◽  
Diffusion Coefficients ◽  
Secondary Organic Aerosol ◽  
Organic Aerosol ◽  
Liquid Phase Separation ◽  
Small Diffusion ◽  
Wide Range ◽  
Liquid Liquid Phase Separation

Abstract. Information on liquid-liquid phase separation (LLPS) and viscosity (or diffusion) within secondary organic aerosol (SOA) is needed to improve predictions of particle size, mass, reactivity, and cloud nucleating properties in the atmosphere. Here we report on LLPS and viscosities within SOA generated by the photooxidation of diesel fuel vapors. Diesel fuel contains a wide range of volatile organic compounds, and SOA generated by the photooxidation of diesel fuel vapors may be a good proxy for SOA from anthropogenic emissions. In our experiments, LLPS occurred over the relative humidity (RH) range of ~ 70 % to ~ 100 %, resulting in an organic-rich outer phase and a water-rich inner phase. These results may have implications for predicting the cloud nucleating properties of anthropogenic SOA since the organic-rich outer phase can lower the kinetic barrier for activation to a cloud droplet. At ≤ 10 % RH, the viscosity was in the range of ≥ 1 × 108 Pa s, which corresponds to roughly the viscosity of tar pitch. At 38–50 % RH the viscosity was in the range of 1 × 108–3 × 105 Pa s. These measured viscosities are consistent with predictions based on oxygen to carbon elemental ratio (O : C) and molar mass as well as predictions based on the number of carbon, hydrogen, and oxygen atoms. Based on the measured viscosities and the Stokes–Einstein relation, at ≤ 10 % RH diffusion coefficients of organics within diesel fuel SOA is ≤ 5.4 × 10−17cm2 s−1 and the mixing time of organics within 200 nm diesel fuel SOA particles (τmixing) is ≳ 50 h. These small diffusion coefficients and large mixing times may be important in laboratory experiments, where SOA is often generated and studied using low RH conditions and on time scales of minutes to hours. At 38–50 % RH, the calculated organic diffusion coefficients are in the range of 5.4 × 10−17 to 1.8 × 10−13 cm2 s−1 and calculated τmixing values are in the range of ~ 0.01 h to ~ 50 h. These values provide important constraints for the physicochemical properties of anthropogenic SOA.

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