Cone Jet Research Articles

Jet overlap in heavy ion collisions at energies available at the CERN Large Hadron Collider and its consequences for the jet shape

Central lead-lead collisions at the LHC energies may pose a particular challenge for jet identification as multiple jets are produced per each collision event. We simulate the jet evolution in central Pb-Pb events at $\sqrt{s_{\rm NN}} = 2.76$ GeV collision energy with EPOS3 initial state, which typically contains multiple hard scatterings in each event. Therefore the partons from different jets have a significant chance to overlap in momentum space. We find that 30% of the jets with $p_\perp > 50$ GeV, identified by the standard anti-$k_\perp$ jet finding algorithm with jet cone size R=0.3, contain `intruder' particles from overlapping generator-level jets. This fraction increases with increasing beam energy and increasing R. The reconstructed momentum of the jet differs from that of the modelled jet by the loss due to jet partons which are outside of the jet cone and by the gain due to intruder partons. The sum of both may be positive or negative. These intruder partons particularly affect the radial jet momentum distribution because they contribute mostly at large angles $\Delta r$ with respect to the jet centre. The study stresses the importance of the jet overlap effect emerging in central lead-lead collisions at the LHC energies, while being negligible in peripheral PbPb or $p$Pb/$pp$ collisions.

Large eddy simulation of base drag reduction using jet boat tail passive flow control

This study conducts an implicit large eddy simulation (ILES) of jet boat tail (JBT) flows to investigate its drag reduction mechanism. The concept of JBT passive flow control is to create a circumferential jet around a bluff body toward the center of the base area. It forms a jet cone to have the similar effect of a solid boat tail. The LES is performed for a baseline bluff body and a JBT model modified from the baseline. The LES predicts that the JBT reduces the averaged drag coefficient by 19.3%, a reasonable agreement with the experimental drag reduction of 22.5%. The reduced averaged wake area is also observed for the JBT model, resulting in a decreased drag. In addition, the unsteady flow structures of the baseline and JBT flow are analyzed to study the flow mixing and entrainment mechanism. For the baseline configuration, the coherent vortex structures occur far downstream of the base surface. It hence does not have strong entrainment and energy transfer from freestream to the base area. For the JBT flow, a pulsative jet is induced by the vortex shedding of the shear layer and interacts immediately with the shear layer near the base surface. It generates the small structures that are substantially larger than those of the baseline configuration. The larger vortex structures of JBT enhance the flow entrainment and transfer more energy from the freestream to the base area. It results in higher static pressure in the base area that substantially reduces the pressure drag. Proper orthogonal decomposition of flow field reveals the periodic jet pulsation pattern in the azimuthal direction.

Fabrication of a Large-Area, Fused Polymer Micromold Based on Electric-Field-Driven (EFD) μ-3D Printing.

An electric-field-driven (EFD), μ-3D printed, fused polymer technique has been developed for the fabrication of large-area microscale prototype molds using typical polymer materials, including microcrystalline wax (MC-wax), polycaprolactone (PCL), and polymathic methacrylate (PMMA). This work proposes an alternative for large area microscale modes and overcomes the limitation of high cost in the traditional mold manufacturing industry. The EFD principle enables printing of fused polymers materials more than one order of magnitude lower than the nozzle diameter, contributing to the necking effect of the Taylor cone jet, which is the key factor to achieve the microscale manufacturing. Numerical simulation of electric field distribution between the meniscus and substrate was carried out to elucidate the dependence of electric field distribution on the meniscus condition of three types of polymers under printable voltage, and the electrical field parameters for the EFD μ-3D printing were determined. A number of experiments were printed successfully using a large range of viscosity materials, ranging from tens of mPa·s to hundreds of thousands of mPa·s of PCL and PMMA. The differences in parameters of different materials, such as viscosity, tensile properties, and surface energy, were studied to assess their use in different fields. Using proper process parameters and a nozzle with an inner diameter of 200 μm, three different application cases were completed, including a Wax microarray and microchannel with a minimum dot diameter of 20 μm, a PCL mesh structure with a minimum line width of 5 μm, and a PMMA large-area mold with a maximum aspect ratio of 0.8. Results show that the EFD μ-3D printing has the outstanding advantages of high printing resolution and polymer material universality.

Multi-objective parameters optimization design of self-excited oscillation pulsed atomizing nozzle

The self-excited oscillation pulsed atomizing nozzle can effectively and evenly spray the high-speed solid cone jet without any extra power. The primary atomization of the jet at the outlet of nozzle directly affects the final spray quality, and the turbulence and cavitation at the outlet of the atomizing nozzle are the other two main factors affecting the atomization. In this work, multi-objective optimization depending on nozzle parameters was established by using mathematical optimization techniques and computational fluid dynamics to improve the jet atomization quality at the outlet of the nozzle. The central composite design method and the response surface method were used to obtain the approximate mathematical model of the primary atomization quality of the jet at the outlet of nozzle. Finally, the non-dominated sorting genetic algorithm with elitist strategy (NSGA-II) and the grey theory were used in combination to optimize the nozzle parameters. Through combining with the NSGA-II and the grey theory, the nozzle parameters were optimized in order to obtain the best primary atomization at the outlet area of nozzle. The optimization results verified the nozzle design with multi-objective optimization method. The optimized values of the turbulent kinetic energy F1 and the vapor volume fraction F2 increased by 28.26% and 5.56%, respectively, and the corresponding nozzle parameters of the chamber diameter D, the lower nozzle diameter d2 and the upper nozzle inlet pressure Pin were, respectively, optimized to 28.056 mm, 5.472 mm and 3.999 Mpa.

On the weak Lyα emission line of BL Lacertae objects

Recent studies reveal that weak Lyα emission line may be a ubiquitous feature of nearby BL Laceratae objects (BL Lacs). We present a survey of the Lyα emission lines in BL Lacs, with a focus on data obtained by the Cosmic Origins Spectrograph onboard the Hubble Space Telescope. Among the 11 selected targets, seven show a clear detection of the intrinsic Lyα emission line, while one manifests a marginal detection. Two of these intrinsic Lyα lines are newly detected in this work (FBQS J1217+3007 and 3C 66A). Most selected BL Lacs are either high or intermediate-frequency peaked BL Lacs, with the only exception being one low-frequency peaked BL Lac. A strong anti-correlation between the line equivalent width and the continuum luminosity was found. The possible sources of ionizing photons that are responsible for production of the Lyα emission line are studied based on a widely accepted detailed accretion-jet model. It is found that the clouds of the broad line region are unlikely to be located in the jet cone region with an inclination angle of less than 10 degrees. Contributions from the jet and disk to the emission lines are found to be comparable. Additionally, a possible way to constrain the accretion rate from the emission line is proposed.

Electrostatic spraying of membrane electrode for proton exchange membrane fuel cell

In order to improve the performance of proton exchange membrane fuel cell (PEMFC), the optimization of electrostatic spraying of membrane electrode was conducted. The influence of the spraying voltage on morphology, elemental composition of catalyst layer, and performance of the PEMFC were investigated. The results show that increasing spraying voltage could reduce agglomeration of the carbon-supported platinum particles, leading to more uniform pore distribution. High voltage did not accelerate oxidation of platinum catalyst. A high electrochemical active surface area of 26.18 m2/gpt was obtained when the platinum-carbon catalyst layer was deposited in cone jet mode. With further increasing spraying voltage, the total ohmic resistance and catalytic activity were changed slightly, whereas the charge transfer resistance was increased. Using the optimized electrostatic spraying parameters (injection rate = 100 μL min−1, spraying voltage = 8.5 kV, and working distance = 12 mm), a peak power density of 1.408 W cm−2 was obtained with an output voltage of 0.451 V.

Aerodynamically stabilized Taylor cone jets.

We introduce a way to stabilize steady micro/nanoliquid jets issuing from Taylor cones together with coflowing gas streams. We study the dripping-jetting transition of this configuration theoretically through a global stability analysis as a function of the governing parameters involved. A balance between the local radial acceleration to the surface tension gradient, the mass conservation, and the energy balance equations enable us to derive two coupled scaling laws that predict both the minimum jet diameter and its maximum velocity. The theoretical prediction provides a single curve that describes not only the numerical computations but also experimental data from the literature for cone jets assisted with gas coflow. Additionally, we performed a set of experiments to verify what parameters influence the jet length. We adopt a very recent model for capillary jet length to our configuration by combining electrohydrodynamic effects with the gas flow through an equivalent liquid pressure. Due to diameters below 1 μm and high speeds attainable in excess of 100 m/s, this concept has the potential to be utilized for structural biology analyses with x-ray free-electron lasers at megahertz repetition rates as well as other applications.

Gas jet flow characteristic of high-pressure methane pulsed injection of single-hole cylindrical nozzle

For a direct injection natural gas engine, the fuel jets into the cylinder in cycles, and this gas pulsed injection process causes crucial effects on the combustion. This study presents an experimental investigation on the methane direct injection. An optical test rig is designed to observe the high-pressure methane jet into a constant-volume bomb (CVB), and a numerical model is built to analyze the gas flow. The methane jet has a two-stage feature. The gas jet characteristic parameters (the tip penetration, penetration speed, jet cone cover area) change rapidly in dynamic stage I, and become stable in stable stage II. The dynamic process inside the nozzle induces this two-stage gas jet flow. The inner methane flow experiences a time delay from the inlet to the outlet, and the gas jet undergoes the same time delay to maintain stable. Furthermore, the injection pressure has great effects on the gas jet. As the injection pressure rises high enough, the gas jet saturation behavior occurs, and it is caused by inner flow saturation of Mach number, Reynolds number and gas velocity inside the nozzle. It is not necessary to increase injection pressure as high as possible for improving the gas jet characteristics.

Interaction between electrospray using ionic liquid and simultaneous corona discharge under positive and negative polarity

One kind of ionic liquid, 1-ethyl-3-methylimidazolium tetrafluoroborate, is used to investigate the interaction between electrospray and corona discharge under positive and negative polarity. A high-speed camera, a digital camera, and an oscilloscope are applied to observe the shape of the meniscus and the jet, photograph the discharge plume, and observe the current waveform of discharge, respectively. The electrospray and discharge modes are studied under different flow rates and voltage conditions, and the experimental results show that there is only corona discharge with no jet at a low flow rate, while the intermittent jet or droplet emission is accompanied by corona discharge at a high flow rate, and no steady cone jet mode is obtained under all experimental conditions. The inevitability of corona discharge in the electrospray process of 1-ethyl-3-methylimidazolium tetrafluoroborate is analyzed from the viewpoint of electric field. Pulse discharge at low voltage depends on the oscillation of the meniscus. The frequency of pulse discharge can be changed indirectly by changing the voltage to control the oscillation of the meniscus. The influence of corona discharge and resultant space charge is not only on the electric field strength, but also on the shape, which is the reason why the liquid surface morphology is significantly different under positive and negative polarities.

Effects of Combustion Vestibule Configuration on the Competence, Emissions and Combustion attributes of Direct Injection Diesel Prime Mover Powered with Diesel and Corn Oil Methyl Ester (CROME)

Combustion processes and emissions attributes squarely depend on combustion vestibule volume shapes relative to injector jet directions and cone angles. For injectors with more number of holes, these parameters change and may result in enhanced performance. By this we can make the gases to flow in different patterns compared to conventional engine and can anticipate higher brake thermal efficiency (BTE) and reduced emanations to meet stringent norms. Hence to optimize combustion chamber shapes (CCS) and vary squish, appropriate injection strategies are essential. In this occasion lab probes were conducted on a single cylinder four stroke open or induction swirl diesel engine using corn oil methyl ester (CROME) as fuel. For this variety of CCS were designed and manufactured. Injector with 6 numbers of hole and 0.2 mm orifice size was used to check its effects on the biodiesel powered engine. The suitable engine available was having Hemispherical Bowl Piston (HBP). To probe the effects of other CCS on the performance of diesel engine, Cylindrical Bowl Piston (CBP), Toroidal Bowl Piston (TBP) and Toroidal Re-entrant Bowl Piston (RBP) vestibule volume shapes were manufactured keeping ratio of compression same. For 100% replacement of diesel by biodiesel the injection pressures and injection timings tested were in the range of 210 bar to 250 bar and 19°bTDC to 27°bTDC which are based on our previous research works on other biodiesels. But the performance was maximised for 240 bar and 27°bTDC for all CCS which is reported in this paper. Engine variables such as fuel flow rate, brake power, torque, and temperature of exhaust smoke, combustion variables such as rate of heat release (HRR), peak pressure (PP), ignition delay (ID), combustion duration (CD), and exhaust emissions such as smoke opacity, HC, CO, and NOx, were measured. Results obtained with RBP shape and for CROME with 6 number of hole injector concluded in overall ameliorated competence with lesser emission levels of CO, HC and smoke, but NOx was almost same as that of diesel. Also reduced ID, CD and increased PP resulted in decreased burning time loss (BTL) increasing competence. Hence this research work shows that the CROME is also compatible and capable of replacing diesel in a diesel engine efficiently.

The Close AGN Reference Survey (CARS)

The [C II]λ158 μm line is one of the strongest far-infrared (FIR) lines and an important coolant in the interstellar medium of galaxies that is accessible out to high redshifts. The excitation of [C II] is complex and can best be studied in detail at low redshifts. Here we report the discovery of the highest global [C II] excess with respect to the FIR luminosity in the nearby AGN host galaxy HE 1353−1917. This galaxy is exceptional among a sample of five targets because the AGN ionization cone and radio jet directly intercept the cold galactic disk. As a consequence, a massive multiphase gas outflow on kiloparsec scales is embedded in an extended narrow-line region. Because HE 1353−1917 is distinguished by these special properties from our four bright AGN, we propose that a global [C II] excess in AGN host galaxies could be a direct signature of a multiphase AGN-driven outflow with a high mass-loading factor.

Experimental study on spray and atomization characteristics under subcritical, transcritical and supercritical conditions of marine diesel engine

In this research, detailed characteristics of diesel spray and atomization based on marine engine scale have been studied under subcritical, transcritical and supercritical conditions. A large constant volume chamber with an inner diameter of 300 mm and a 300 μm single-nozzle injector are used to mimic the in-cylinder thermodynamic condition of marine diesel engine. Sub/trans/supercritical conditions are composed of nine cases by means of different diesel phase transition regions. Optical diagnostic measurements are conducted through backlight illumination technology and schlieren imaging technology in an inert atmosphere. The images are processed with multi-threshold technique to obtain quantitative spray parameters, such as jet and liquid penetrations, averaged lengths, liquid steady time, spray cone angles and R-parameter. Moreover, some new finding about the structure of spray under supercritical condition is also discussed. The results show that the spray liquid periphery is quite smooth and stable with shorter penetration under supercritical condition, meanwhile, the jet of spray behaves as thinner periphery near the injector nozzle region and shows lower density at downstream region. Higher ambient pressure produces a negative effect on the increase of the tip velocity and development of spray. With the transition from transcritical condition to supercritical condition, the liquid length decreases by 32 mm and there exists an obvious decrease of 35 mm from jet length to liquid length. A trade-off relationship between the jet cone angle and jet penetration is also found. Generally, this work is helpful to understand the detailed process of diesel atomization under transcritical and supercritical conditions.

Preparation of Electrosprayed Poly(caprolactone) Microparticles Based on Green Solvents and Related Investigations on the Effects of Solution Properties as Well as Operating Parameters

Electrosprayed poly(caprolactone) (PCL) microparticles were produced using five solvents (ethyl acetate, acetone, anisole, glacial acetic acid and chloroform) under different PCL concentrations and operating parameters. Not only green and appropriate solvent for PCL electrospraying was pointed out, but also the effects of solution properties (surface tension, electrical conductivity, viscosity and vapor pressure) and operating parameters (flow rate, working distance and applied voltage) on the formation of electrosprayed particles were clarified. The formation and shape of Taylor cone during electrospraying was observed by high-speed images captured with a camera, and the size and morphology of electrosprayed particles were characterized by optical and scanning electron microscopies. It can conclude that the cone–jet range of applied voltage mainly depended on electrical conductivity, and an ideal Taylor cone was easier to form under high viscosity and low surface tension. Although high electrical conductivity was a contributor to fabricate tiny particles, it was easier to fabricate mono-dispersed microparticles under low electrical conductivity. The poly-dispersed distribution obtained with a high electrical conductivity converted into mono-dispersed distribution with the increasing of viscosity. Furthermore, the size of electrosprayed particles also correlated with the surface tension and vapor pressure of the solvent used. Ethyl acetate, due to mild electrical conductivity and surface tension, moderate viscosity and vapor pressure, is a green and suitable solvent for PCL electrospraying. Single pore PCL microparticles with smooth cherry-like morphology can be prepared from ethyl acetate. Finally, long working distance not only stabilizes the break-up of charged jet, but also promotes the evaporation of solvent.

Effects of cone combinations on accurate and precise Mg-isotopic determination using multi-collector inductively coupled plasma mass spectrometry.

High-precision determination of magnesium (Mg) isotopes can now be routinely achieved by multi-collector inductively coupled plasma mass spectrometry (MC-ICP-MS). The analytical sensitivity and instrumental mass discrimination behavior of this method are, however, sensitive to the types of sample and skimmer cones used in these measurements, so it is important that these parameters should be investigated. Using the sample-standard-bracketing method in the wet-plasma mode, four available combinations of sample and skimmer cones [Jet sample cone + H skimmer cone (Jet + H), standard sample cone + H skimmer cone (Standard + H), standard sample cone + X skimmer cone (Standard + X), and Jet sample cone + X skimmer cone (Jet + X)] were systematically investigated for peak shape, sensitivity, mass discrimination, accuracy, and precision in Mg-isotopic ratio determination using a Neptune plus MC-ICP mass spectrometer. The results showed that different cone combinations do not affect peak shapes but would significantly change the sensitivities for Mg-isotopic determinations. Compared with using the Standard + H, the sensitivities of Mg-isotopic determinations were enhanced by approximately a factor of 1.3, 1.4, and 1.9 by using the Standard + X, the Jet + H, and the Jet + X combinations, with the most stable mass discrimination behaviors obtained by the Jet + H. The instrumental mass fractionation slope for any combination of a modified cone geometry (i.e. Standard + X, Jet + X, and Jet + H) is 0.500, while it is 0.510 for the Standard + H. In addition, the mass discrimination behavior is related to Mg concentrations once the combination is set, indicating the necessity of concentration match during Mg-isotopic determination. The precision and accuracy of the Jet + H combination are better than those of the other combinations, and this is further supported by the validation of the Mg-isotope data for four international reference materials: Cambridge-1, NASS-6, AGV-2, and BHVO-2. As the Jet + H combination also provides a high signal, this combination gives the most robust strategy for the highly precise and accurate determination of Mg isotopes.

Simulation and Validation of Droplet Generation Process for Revealing Three Design Constraints in Electrohydrodynamic Jet Printing.

Droplet generation process can directly affect process regulation and output performance of electrohydrodynamic jet (E-jet) printing in fabricating micro-to-nano scale functional structures. This paper proposes a numerical simulation model for whole process of droplet generation of E-jet printing based on the Taylor-Melcher leaky-dielectric model. The whole process of droplet generation is successfully simulated in one whole cycle, including Taylor cone generation, jet onset, jet break, and jet retraction. The feasibility and accuracy of the numerical simulation model is validated by a 30G stainless nozzle with inner diameter ~160 μm by E-jet printing experiments. Comparing numerical simulations and experimental results, period, velocity magnitude, four steps in an injection cycle, and shape of jet in each step are in good agreement. Further simulations are performed to reveal three design constraints against applied voltage, flow rate, and nozzle diameter, respectively. The established cone-jet numerical simulation model paves the way to investigate influences of process parameters and guide design of printheads for E-jet printing system with high performance in the future.

Measurement of angular and momentum distributions of charged particles within and around jets in Pb+Pb and pp collisions at [formula omitted] with ATLAS at the LHC

Studies of the fragmentation of jets into charged particles in heavy-ion collisions can help in understanding the mechanism of jet quenching by the hot and dense QCD matter created in such collisions, the quark-gluon plasma. These proceedings present a measurement of the angular distribution of charged particles around the jet axis in sNN=5.02TeV Pb+Pb and pp collisions, done using the ATLAS detector at the LHC. The measurement is performed inside jets reconstructed with the anti-kt algorithm with radius parameter R=0.4, and is extended to regions outside the jet cone. Results are presented as a function of Pb+Pb collision centrality, and both jet and charged-particle transverse momenta.

Possible evidence of a supermassive black hole binary with two radio jets in blazar 3C279

Context. Studies of periodic and quasi-periodic phenomena in optical and radio bands are important for understanding the physical processes in quasars. Investigation of periodic/quasi-periodic behavior of the relativistic jets in blazars is particularly significant because it can provide unique information about the formation, collimation, and acceleration of the jets and the properties of the central engines (black hole/accretion disk systems) in blazars. Aims. We investigate the parsec-scale kinematics of the 31 superluminal components observed in blazar 3C279 and attempt to search for evidence of its jet precession and double-jet structure. Methods. The previously suggested precessing jet nozzle model is applied to model-fit the kinematics of its superluminal components observed during the 1981–2015 period. It is shown that the parsec-scale kinematics of the entire source can be interpreted in terms of a double-jet scenario. Results. The superluminal components observed in 3C279 can be divided into two groups that are ejected from two relativistic jets. The two jets have different orientations in space and jet-cone shapes, but both jets precess with the same precession period of 25 yr (16.3 yr in the source frame). The kinematic features of all the superluminal knots (trajectory, core separation, and apparent velocity) can be consistently explained. Their innermost trajectories follow the respective precessing common parabolic patterns with trajectory curvatures that occurred in the outer jet regions at different core separations. The bulk Lorentz factor, Doppler factor, and viewing angle of their motion are derived. The unusual jet-direction change of ∼100° observed in 2010–2011 can be naturally explained. Conclusions. We propose a double-jet structure scenario for 3C279 and suggest that there may be a supermassive black hole binary in the center of 3C279 ejecting two precessing relativistic jets, resulting in its very complex structure and kinematics on parsec scales, and with extremely variable emission across the electromagnetic spectrum. Because the two jets have the same precession period, the precession of the double jet may have originated from the modulation of their jet orientation by the change in their orbital velocity direction relative to the observer. In this case the mass ratio m/M of the binary is approximately equal to the ratio of the jet cone widths, being on the order of ∼0.5.

Electro-encapsulation of Lactobacillus casei in high-resistant capsules of whey protein containing transglutaminase enzyme

In this study, we aimed to evaluate the possibility of obtaining natural high-resistant protein capsules from aqueous solution of whey protein containing transglutaminase (TG) enzyme through electrohydrodynamic atomization (EHDA) as an appropriate system, and freeze-drying (FD) technique as the control method for encapsulation of Lactobacillus casei. A stable cone jet was achieved in a certain electrical conductivity, surface tension, and viscosity values equal to 1681 ± 8.49 μS, 48.97 ± 0.02 mN/m, and 51.96 ± 0.78 cP, respectively. Spherical water-resistant capsules with an average diameter of 3.09 ± 1.04 μm were obtained through the EHDA process. A comparison between the EHDA and FD revealed higher encapsulation efficiency of the electrospraying technique as well as greater viability of L. casei under the simulated gastrointestinal (GI) tract. DSC results showed that the enthalpy of cross-linked samples was decreased by incorporating TG enzyme. In contrast to freeze-dried structures, electrosprayed capsules revealed better protection during the storage, especially in the second and third months.

Clumpy jets from black hole–massive star binaries as engines of fast radio bursts

We propose a new model of Fast Radio Bursts (FRBs) based on stellar mass black hole-massive star binaries. We argue that the inhomogeneity of the circumstellar materials or/and the time varying wind activities of the stellar companion will cause the black hole to accrete at a transient super-Eddington rate. The collision among the clumpy ejecta in the resulted jet could trigger plasma instability. As a result, the plasma in the jet will emit coherent curvature radiation. When the jet cone aims toward the observer, the apparent luminosity can be $10^{41}-10^{42}$\,erg/s. The duration of the resulted flare is $\sim$ millisecond. The high event rate of the observed non-repeating FRBs can be explained. A similar scenario in the vicinity of a supermassive black hole can be used to explain the interval distribution of the repeating source FRB121102 qualitatively.

Numerical simulation of electrospraying in the cone-jet mode

This article solves numerically the equations of the leaky-dielectric model applied to cone jets. The solution is a function of the properties of the fluid and its flow rate, universal in that it does not depend on the geometry and potential of the electrodes. This is made possible by the use of the potential field generated by a semi-infinite Taylor cone as a far-field boundary condition. The numerical solution yields the current emitted by the electrospray, which compares well with experimental data, and detailed information about the velocity, surface charge, electric field and the position of the free surface. These characteristics are generally inaccessible through experiments, and are needed to understand the relative importance of competing processes and the dominant physics. The simulations investigate the liquids tributyl phosphate and propylene carbonate (dielectric constants of 8.91 and 64.9 respectively), in a wide range of electrical conductivities and flow rates. The simulations show that the position of the surface, expressed in units of the characteristic length $r_{c}$, is largely invariant regardless of the physical properties and flow rates of the liquids. The surface charge falls below its equilibrium value along the transition from cone to jet, with a deficit that increases with the ratio between the electrical relaxation and flow residence times. Several characteristics of the cone jet are functions of the dielectric constant, which is consistent with the importance of charge relaxation effects (i.e. with the absence of surface charge equilibrium). The electric energy transferred to the transition region is largely transformed into viscous and ohmic dissipation, and conversion into kinetic energy only dominates once most of the current is fixed on the surface.