Effects of orifice divergence on hollow cone spray at low injection pressures

2018 ◽  
Vol 233 (11) ◽  
pp. 4091-4105 ◽  
Author(s):  
Kushal Ghate ◽  
Thirumalachari Sundararajan
Keyword(s):  
Cone Angle ◽  
Sheet Thickness ◽  
Liquid Sheet ◽  
Divergence Angle ◽  
Sauter Mean Diameter ◽  
Spray Cone Angle ◽  
Spray Cone ◽  
Air Core ◽  
Mean Diameter ◽  
Injection Pressures

In this work, the effects of orifice divergence on spray characteristics have been reported. Parameters such as spray cone angle, liquid sheet thickness, coefficient of discharge, break-up length, and Sauter mean diameter are greatly affected by the half divergence angle [Formula: see text] at orifice exit. An experimental investigation is carried out in which water sprays from five atomizers having half divergence angle values of 0°, 5°, 10°, 15°, and 20° are studied at different injection pressures. Image processing techniques are used to measure spray cone angle and break-up length from spray images, whereas the sheet thickness outside the orifice exit is obtained using the scattered light from a thin Nd-YAG Laser beam. Phase Doppler interferometry is also used to obtain the Sauter mean diameter at different axial locations. A few numerical simulations based on the volume of fluid method are included to obtain physical insight of the liquid film development and air core flow inside the atomizer. It is observed that the liquid sheet thickness as well as tangential and radial components of velocity at orifice exit are modified drastically with a change in half divergence angle. As a consequence, the droplet size distribution is also altered by variation in the nozzle divergence angle. The mechanism responsible for such variations in the spray behavior is identified as the formation of an air core or air cone inside the liquid injector as a result of the swirl imparted to the liquid flow.

scholarly journals Effect of Inlet Tangential Port Area on the Performance of Small – Scale Simplex Atomizer

2012 ◽  
Author(s):  
Selvan G. Muthu ◽  
H. S. Muralidhara ◽  
Vinod Kumar Vyas ◽  
Kanth T. P. Dinesh ◽  
S. Kumaran ◽  
...  
Keyword(s):  
Size Distribution ◽  
Droplet Size ◽  
Cone Angle ◽  
Droplet Size Distribution ◽  
Small Scale ◽  
Sauter Mean Diameter ◽  
Spray Cone Angle ◽  
Spray Cone ◽  
Mean Diameter ◽  
Coefficient Of Discharge

An experimental investigation was conducted to study the effects of increased area of inlet tangential ports on the performance of small scale simplex atomizer. The spray characteristics of three different simplex atomizer representing increasing area of inlet tangential ports are examined using water as a working fluid. Measurements of coefficient of discharge, spray cone angle, Sauter mean diameter and droplet size distribution were carried out over wide range of injection pressure. Coriolis mass flow meter was used to measure coefficient of discharge. Spray cone angle was measured by image processing technique. Sauter mean diameter and droplet size distributions were measured by Malvern droplet sizing instrument. It was observed that with increase in area of inlet tangential ports the size of air core produced along the center line reduced, which increases the coefficient of discharge. Spray cone angle decreases with increase in area of inlet tangential ports. It was found that increase in area of inlet tangential ports reduces swirl strength inside swirl chamber, which results in increasing Sauter mean diameter. Better droplet size distribution was observed for lower area of inlet tangential port configuration. The obtained experimental results were compared with experimental correlations available in literatures. Deviations in the obtained experimental results and experimental correlations was observed. This is due to difference in the size of atomizer used and difference in experimental techniques used between the present work and other investigations.

Effect of nozzle inlet parameters on the dry granulation atomization process of Si3N4 ceramic bearing balls

2021 ◽  
Vol 12 (06) ◽  
pp. 2150058
Author(s):  
Dongling Yu ◽  
Xiaohui Zhang ◽  
Hongbin Luo ◽  
Dahai Liao ◽  
Nanxing Wu
Keyword(s):  
Deflection Angle ◽  
Cone Angle ◽  
Spray Cone Angle ◽  
Spray Cone ◽  
Dry Granulation ◽  
Air Core ◽  
Mean Diameter ◽  
The Mean ◽  
The Deflection Angle ◽  
Pressure Swirl

In this paper, the atomization characteristics of Si3N4 ceramic dry granulation affect the performance of Si3N4 ceramic bearing balls. In order to improve the dry granulation characteristics and the comprehensive performance of Si3N4 ceramic bearing balls, the atomization mechanism of the spinning nozzle used for Si3N4 dry granulation was studied in detail. The interaction between air and binder in the pressure-swirl nozzle is analyzed based on VOF method, the modified realizable [Formula: see text] turbulence model is used to simulate the flow field inside and outside the pressure-swirl nozzle, the effects of nozzle inlet parameters including the number of tangential inlets and the deflection angle of tangential inlets on the binder volume fraction, velocity distribution and pressure distribution are analyzed. The results show that when the number of tangential inlets increases from 1 to 4, the swirl strength of gas–liquid two-phase in the nozzle increases, the mean diameter of air core increases from 1.51[Formula: see text]mm to 2.01[Formula: see text]mm, and the spray cone angle increases from 18.5[Formula: see text] to 26.4[Formula: see text]. Besides, when the deflection angle of tangential inlet increases from 0[Formula: see text] to 15[Formula: see text], the swirl strength of gas–liquid two-phase in the nozzle with the deflection angle of tangential inlet of 10[Formula: see text] is the largest, and the mean diameter of air core and spray cone angle is 3.04[Formula: see text]mm and 30.7[Formula: see text], respectively. Based on the atomization experiment platform of the electric control fuel system, the mean diameter of air core and spray cone angle are measured, the micromorphology of Si3N4 particles is observed, which verifies the correctness of numerical simulation. When the Si3N4 particles are prepared by dry granulation, taking the atomization performance of nozzle into consideration, the pressure-swirl nozzle with 4 tangential inlets and 10[Formula: see text] deflection angle should be selected.

scholarly journals Spray and atomization characteristics of gas-centered swirl coaxial injectors

2016 ◽  
Vol 9 (2) ◽  
pp. 127-140 ◽  
Author(s):  
Rahul Anand ◽  
PR Ajayalal ◽  
Vikash Kumar ◽  
A Salih ◽  
K Nandakumar
Keyword(s):  
Rocket Engine ◽  
Cone Angle ◽  
Spray Angle ◽  
Rocket Engines ◽  
Sauter Mean Diameter ◽  
Swirl Number ◽  
Spray Cone ◽  
Mean Diameter ◽  
Atomization Characteristics ◽  
Coaxial Injector

To achieve uniform and efficient combustion in a rocket engine, a fine uniform spray is needed. The same is achieved by designing an injector with good atomization characteristics. Gas-centered swirl coaxial (GCSC) injector elements have been preferred recently in liquid rocket engines because of an inherent capability to dampen the pressure oscillations in the thrust chamber. The gas-centered swirl coaxial injector chosen for this study is proposed to be used in a semi-cryogenic rocket engine operating with oxidizer rich hot exhaust gases from the pre-burner and liquid kerosene as fuel. In this paper, nine different configurations of gas-centered swirl coaxial injector, sorted out by studying the spray angle and coefficient of discharge with swirl number varying from 9 to 20 and recess ratio of 0.5, 1, and 1.5 are investigated for their atomization characteristics. Spray uniformity, spray cone angle, and droplet size in terms of Sauter mean diameter and mass median diameter are studied at various momentum flux ratios for all configurations. Sauter mean diameter is almost independent of recess ratio, whereas cone angle was inversely proportional to the recess ratio. A finer atomization was observed for injectors of high swirl number but the pressure drop also increased to achieve the same flow rate. An injector of medium swirl number and recess ratio of 1.5 is deemed most fit for above-mentioned application.

Spray Performance of Alternative Jet Fuel Based Nanofuels at High-Ambient Conditions

2018 ◽  
Author(s):  
Mohamed Soltan ◽  
Buthaina Al Abdulla ◽  
AlReem Al Dosari ◽  
Kumaran Kannaiyan ◽  
Reza Sadr
Keyword(s):  
Ambient Pressure ◽  
Cone Angle ◽  
Jet Fuel ◽  
Liquid Sheet ◽  
Ambient Conditions ◽  
Spray Characteristics ◽  
Atomization Process ◽  
Spray Cone Angle ◽  
Spray Cone ◽  
Sheet Breakup

Dispersion of nanoparticles in pure fuels alters their key fuel physical properties, which could affect their atomization process, and in turn, their combustion and emission characteristics in a combustion chamber. Therefore, it is essential to have a thorough knowledge of the atomization characteristics of nanofuels (nanoparticles dispersed in pure fuels) to better understand their latter processes. This serves as the motivation for the present work, which attempts to gain a good understanding of the atomization process of the alternative, gas-to-liquid (GTL), jet fuel based nanofuels. The macroscopic spray characteristics such as spray cone angle, liquid sheet breakup, and liquid sheet velocity are determined by employing shadowgraph imaging technique. The effect of nanoparticles weight concentration and ambient pressures on the spray characteristics are investigated in a high pressure-high temperature constant volume spray rig. To this end, a pressure swirl nozzle with an exit diameter of 0.8 mm is used to atomize the fuels. The macroscopic spray results demonstrate that the nanoparticles dispersion at low concentrations affect the near nozzle region. The spray liquid sheet breakup distance is reduced by the presence of nanoparticle due to the early onset of disruption in the liquid sheet. Consequently, the liquid sheet velocity in that spray region is higher for nanofuels when compared to that of pure fuels. Also, the ambient pressure has a significant effect on the spray features as reported in the literature.

scholarly journals Spray cone angle and air core diameter of hollow cone swirl rocket injector

2011 ◽  
Vol 12 (3) ◽  
Author(s):  
Ahmad Hussein Abdul Hamid
Keyword(s):  
Cone Angle ◽  
Injection Pressure ◽  
Combustion Efficiency ◽  
Fuel Injector ◽  
Hollow Cone ◽  
Spray Cone Angle ◽  
Core Diameter ◽  
Spray Cone ◽  
Air Core ◽  
Liquid Rocket

ABSTRACT : Fuel injector for liquid rocket is a very critical component since that small difference in its design can dramatically affect the combustion efficiency. The primary function of the injector is to break the fuel up into very small droplets. The smaller droplets are necessary for fast quiet ignition and to establish a flame front close to the injector head, thus shorter combustion chamber is possible to be utilized. This paper presents an experimetal investigation of a mono-propellant hollow cone swirl injector. Several injectors with different configuration were investigated under cold flow test, where water is used as simulation fluid. This investigation reveals that higher injection pressure leads to higher spray cone angle. The effect of injection pressure on spray cone angle is more prominent for injector with least number of tangential ports. Furthermore, it was found that injector with the most number of tangential ports and with the smallest tangential port diameter produces the widest resulting spray. Experimental data also tells that the diameter of an air core that forms inside the swirl chamber is largest for the injector with smallest tangential port diameter and least number of tangential ports.ABSTRAK : Injektor bahan api bagi roket cecair merupakan satu komponen yang amat kritikal memandangkan perbezaan kecil dalam reka bentuknya akan secara langsung mempengaruhi kecekapan pembakaran. Fungsi utama injektor adalah untuk memecahkan bahan api kepada titisan yang amat kecil. Titisan kecil penting untuk pembakaran pantas secara senyap dan untuk mewujudkan satu nyalaan di hadapan, berhampiran dengan kepala injektor, maka kebuk pembakaran yang lebih pendek berkemungkinan dapat digunakan. Kertas kerja ini mebentangkan satu penyelidikan eksperimental sebuah injektor ekabahan dorong geronggang kon pusar. Beberapa injektor dengan konfigurasi berbeza telah dikaji di bawah ujian aliran sejuk, di mana air digunakan sebagai bendalir simulasi. Kajian ini mendedahkan bahawa suntikan bertekanan tinggi menghasilkan sudut semburan kon yang besar. Kesan tekanan suntikan ke atas sudut semburan kon lebih ketara pada injektor yang mempunyai lubang tangen yang kurang Tambahan pula, injektor yang mempunyai jumlah lubang tangen yang paling banyak dan lubang tangen berdiameter paling kecil menghasilkan semburan yang paling lebar. Data eksperimental juga menunjukkan bahawa diameter teras udara terbesar terhasil di dalam kebuk pusar injektor yang mempunyai diameter lubang tangen terkecil dan jumlah lubang tangen yang paling kurang.

scholarly journals The effect of using different Biodiesel fuels on jet development in a Diesel engine

2022 ◽  
Vol 960 (1) ◽  
pp. 012011
Author(s):  
Andrei Laurentiu Niculae ◽  
Radu Chiriac ◽  
Alexandru Racovitza
Keyword(s):  
Cone Angle ◽  
Injection Rate ◽  
Injection System ◽  
Sauter Mean Diameter ◽  
Spray Cone ◽  
Engine Operation ◽  
Fuel Jet ◽  
Mean Diameter ◽  
Biodiesel Fuels ◽  
Jet Characteristics

Abstract The fuel properties and the injection rate-shape play an important role in the improvement of the combustion process of Diesel engines. In this work, the influences of using the forthcoming renewable biodiesel fuels on fuel jet development utilizing a computer simulation model created with the AVL Hydsim software were studied. Biodiesel fuels B20, B30 and B100 were considered and compared with the original pure Diesel fuel D100. The injection system behaviour under research was that one existing on a tractor engine equipped with Delphi DP200 pump and Delphi injectors. Two engine speeds of 1400 rpm and 2400 rpm were considered representative for the engine operation. For these speeds, the fuel jet characteristics as penetration, spray cone angle and Sauter mean diameter were analyzed. It can emphasize that in similar conditions of needle lift and injection rate-shape variation the usage of biodiesel fuels does not significantly alter the injection pressure and the Sauter mean diameter. However, the specific physical properties of biodiesel fuels affect substantially the spray penetration and its cone angle.

Axial and Radial Variation of Spray Characteristics of a Small-Scale Simplex Atomizer

2014 ◽  
Author(s):  
Muthuselvan Govindaraj ◽  
Muralidhara Halebidu Suryanarayana ◽  
Vinod Kumar Vyas ◽  
Jeyaseelan Rajendran ◽  
Rajeshwari Natarajan ◽  
...  
Keyword(s):  
Size Distribution ◽  
Droplet Size ◽  
Radial Direction ◽  
Cone Angle ◽  
Injection Pressure ◽  
Droplet Size Distribution ◽  
Axial Direction ◽  
Spray Cone Angle ◽  
Spray Cone ◽  
Injection Pressures

Simplex atomizer is widely used in the liquid fuel combustion devices in aerospace and power generation industries. An experimental work was conducted, to study variation of SMD and droplet size distribution along axial and radial directions of the spray for different injection pressures. Malvern spray analyzer is used in the present investigation. Four different atomizer configurations of increasing atomizer constant (K) are examined using water and kerosene. Spray cone angle is measured for different configurations at different injection pressures (up to 30 bar) using image processing technique. In the case of atomizer with lower K, spray cone angle continuously increases with injection pressure. In the case of atomizer with higher K, initially spray cone angle increases significantly, but remains almost constant after 16 bar. Variation of SMD and droplet size distribution along axial direction of the spray is compared between water and kerosene spray. SMD variation along the axial direction of spray clearly shows the continuous brakup of droplets along axial direction of the spray. In the case of water spray, SMD rapidly decreases along the axial direction up to 30 mm from the orifice exit, and gradually decreases up to 120 mm. In the case of kerosene spray, SMD rapidly decreases along the axial direction up to 40 mm from the orifice exit, after that SMD fluctuates along the axial direction up to 100 mm from the orifice exit. This fluctuation is due to evaporation of smaller droplets (50 microns) of kerosene. Span also continuously fluctuates after 40 mm from the orifice exit in the case of kerosene spray. Variation of SMD and droplet size distribution along radial direction of the spray is compared for different injection pressure and configurations of simplex atomizer. Increase in injection pressure, increases the disruptive aerodynamic force, which reduces the radial peak value of SMD and widens the radial profile. With decrease in atomizer constant (K), swirl strength inside the swirl chamber increases, which in turn increases the spray cone angle. SMD variation along the radial direction of spray showed more uniform droplet diameter distribution for lower atomizer constant (K) configurations. Reducing the atomizer constant improves the atomization quality more effectively than increasing the injection pressure.

Sign in / Sign up

Export Citation Format

Share Document