Experimental and numerical study of the effects of nozzle taper angle on spray characteristics of GDI multi-hole injectors at cold condition

The performance and capacity of Kraft recovery boilers is sensitive to black liquor velocity, droplet size and flow distribution in the furnace. Studies have shown that controlling droplet size and flow distribution improves boiler efficiency while allowing increased flight drying and devolatilization, and decreased carryover. The purpose of this study is to develop a robust two-phase numerical model to predict black liquor splashplate nozzle spray characteristics. A three-dimensional time dependent numerical study of black liquor sheet formation and sheet breakup is described. The volume of fluid (VOF) model is used to simulate flow through the splashplate nozzle up to initial sheet breakup and droplet formation. The VOF model solves the conservation equations of volume fraction and momentum utilizing the finite volume technique. Black liquor velocity, droplet size and flow distribution over a range of operating parameters are simulated using scaled physical models of splashplate nozzles. The VOF model is compared to results from a flow visualization experiment and experimental data found in the literature. The details of the simulation and experimental results are presented.

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A Numerical Study of Spray Characteristics in Medium Speed Engine Fueled by Different HFO/n-Butanol Blends

International Journal of Chemical Engineering ◽

10.1155/2014/702890 ◽

2014 ◽

Vol 2014 ◽

pp. 1-13 ◽

Cited By ~ 5

Author(s):

Hashem Nowruzi ◽

Parviz Ghadimi ◽

Mehdi Yousefifard

Keyword(s):

Average Velocity ◽

Numerical Study ◽

Injection Pressure ◽

Fuel Oil ◽

Heavy Fuel Oil ◽

Spray Characteristics ◽

Good Compliance ◽

Medium Speed ◽

Medium Speed Engine ◽

Speed Engine

In the present study, nonreacting and nonevaporating spray characteristics of heavy fuel oil (HFO)/n-butanol blends are numerically investigated under two different high pressure injections in medium speed engines. An Eulerian-Lagrangian multiphase scheme is used to simulate blend of C14H30as HFO and 0%, 10%, 15%, and 20% by volume of n-butanol. OpenFOAM CFD toolbox is modified and implemented to study the effect of different blends of HFO/n-butanol on the spray characteristics at 600 and 1000 bar. To validate the presented simulations, current numerical results are compared against existing experimental data and good compliance is achieved. Based on the numerical findings, addition of n-butanol to HFO increases the particles volume in parcels at 600 bar. It was also found that blend fuels increase the number of spray particles and the average velocity of spray compared to pure HFO. Moreover, under injection pressure of 1000 bar, HFO/n-butanol blends compared to pure HFO fuel decrease particles volume in parcels of spray. Another influence of HFO/n-butanol blends is the decrease in average of particles diameter in parcels. Meanwhile, the effect of HFO/n-butanol on spray length is proved to be negligible. Finally, it can be concluded that higher injection pressure improves the spray efficiency.

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Numerical Study on Isooctane and Ethanol Spray Characteristics of a TGDI Injector

Transactions of the Korean Society of Mechanical Engineers B ◽

10.3795/ksme-b.2019.43.1.045 ◽

2019 ◽

Vol 43 (1) ◽

pp. 45-51

Author(s):

Jong Geun Choi ◽

Yong Seok Cho ◽

Jun Sang Yoo ◽

Tae Yong Lee ◽

Seok Jong An ◽

...

Keyword(s):

Numerical Study ◽

Spray Characteristics

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E104 AN EXPERIMENTAL AND NUMERICAL STUDY OF SPRAY CHARACTERISTICS ON MULTI-COMPONENT FUEL

The Proceedings of the International Conference on Power Engineering (ICOPE) ◽

10.1299/jsmeicope.2003.1._1-247_ ◽

2003 ◽

Vol 2003.1 (0) ◽

pp. _1-247_-_1-252_

Author(s):

Kwang Jae Myong ◽

Motoyuki Arai ◽

Tomoyuki Tanaka ◽

Jiro Senda ◽

Hajime Fujimoto

Keyword(s):

Numerical Study ◽

Spray Characteristics

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A numerical study of the effects of injection rate shape on combustion and emission of diesel engines

Thermal Science ◽

10.2298/tsci130810013h ◽

2014 ◽

Vol 18 (1) ◽

pp. 67-78 ◽

Cited By ~ 9

Author(s):

Zhixia He ◽

Tiemin Xuan ◽

Yanru Xue ◽

Qian Wang ◽

Liang Zhang

Keyword(s):

Diesel Engines ◽

Numerical Study ◽

Numerical Models ◽

Injection Pressure ◽

Injection Rate ◽

Spray Characteristics ◽

Penetration Length ◽

Emission Performance ◽

Injection Duration ◽

Hump Shape

The spray characteristics including spray droplet sizes, droplet distribution, spray tip penetration length and spray diffusion angle directly affects the mixture process of fuel and oxygen and then plays an important role for the improvement of combustion and emission performance of diesel engines. Different injection rate shapes may induce different spray characteristics and then further affect the subsequent combustion and emission performance of diesel engines. In this paper, the spray and combustion processes based on four different injection rate shapes with constant injection duration and injected fuel mass were simulated in the software of AVL FIRE. The numerical models were validated through comparing the results from the simulation with those from experiment. It was found that the dynamic of diesel engines with the new proposed hump shape of injection rate and the original saddle shape is better than that with the injection rate of rectangle and triangle shape, but the emission of NOX is higher. And the soot emission is lowest during the late injection period for the new hump-shape injection rate because of a higher oxidation rate with a better mixture between fuel and air under the high injection pressure.

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Numerical Study of Effects of Separating Efficiency with the Structural Dimensions

Advanced Materials Research ◽

10.4028/www.scientific.net/amr.308-310.232 ◽

2011 ◽

Vol 308-310 ◽

pp. 232-236

Author(s):

Wei Wang ◽

Fang Pu Yang ◽

Jing Bao Shi ◽

Ming Fu Luo

Keyword(s):

Numerical Study ◽

Petroleum Industry ◽

Cyclone Separator ◽

Structural Dimension ◽

Taper Angle ◽

Separation Technology ◽

Bottom Hole ◽

Structural Dimensions

With the development of the petroleum industry ,the separation technology has made progress. The cyclone separator with different structure sizes (such as taper Angle, import hole, overflow hole and bottom hole) are numerical simulated. The separating efficiency are greatly influenced by structural dimension through studied.

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Tapered Twisted Tape Inserts for Enhanced Heat Transfer

Journal of Heat Transfer ◽

10.1115/1.4031207 ◽

2015 ◽

Vol 138 (1) ◽

Cited By ~ 9

Author(s):

B. V. N. Ramakumar ◽

J. D. Arsha ◽

Praveen Tayal

Keyword(s):

Heat Transfer ◽

Numerical Study ◽

Flow Direction ◽

Twisted Tape ◽

Complex Flow ◽

Ansys Fluent ◽

Taper Angle ◽

Twisted Tapes ◽

Plain Tube ◽

Enhancing Heat Transfer

Insertion of twisted tapes in smooth channels is one of the passive methods used for enhancing heat transfer. Flow and associated heat transfer characteristics of these channels are very complex. Understanding this complex flow is helpful while designing new passive methods. Numerical methods like computational fluid dynamics (CFD) are gaining much popularity for analyzing and designing these heat transfer enhancement techniques. This paper focuses on such a numerical study. The preliminary study is focused on development of numerical methodology through validation. Successive studies are aimed at development of an innovative design for twisted tape. Twisted tapes with taper angle (tapered twisted tapes, i.e., tape width decreases along the flow direction) are developed and evaluated on the basis of the performance of these tapes with those of conventional tapes. A circular tube with tapered twisted tape with a twist ratio of 3 and taper angles of 0.3, 0.4, 0.5, 0.6, and 0.7 is considered for this study along with a plain tube. Three Reynolds numbers (Re) of 8545, 11393, and 13333 are considered to examine the sensitivity of the performance. Simulations are performed with a commercially available CFD tool, ansys fluent (v14.0). Heat transfer and pressure drop results are presented in the form of Nusselt number (Nu), friction factor (f), and overall enhancement ratio (η). An increase of 17% in overall enhancement is predicted with taper angle of 0.5.

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