Multi-hole Injector Research Articles

Investigation of fuel temperature and injection timing effects on ammonia direct injection in an optical engine

This work investigates the effects of fuel temperature and injection timing on ammonia direct injection in an optical engine using a multi-hole injector. Flash-boiling may occur over various engine-relevant conditions due to ammonia’s high vapor pressure. This phenomenon impacts spray characteristics and, in severe cases, facilitates cavitation inside the nozzle. Both fuel temperature and injection timing (i.e., ambient conditions during injection) impact the intensity of flash-boiling during fuel injection. Therefore, this work varies fuel temperature (from 320K to 388K) and injection timing (from −60CADaTDC (crank angle degrees after top dead center) to −6CADaTDC) to assess their impact on injection mass flux, discharge coefficients, and macroscopic spray characteristics using an ammonia injection pressure of 200bar. For this purpose, the injection mass is measured by analyzing exhaust gas compositions during engine operation with ammonia injections but without combustion. In addition, diffuse background illumination (DBI) images capture the liquid phase of the fuel spray to characterize spray behavior. The findings reveal that increasing fuel temperature decreases ammonia’s injection mass by up to 12.8% but has little impact on discharge coefficients for late injection timings and high in-cylinder pressures. However, discharge coefficients decrease by up to 17.4% (from 0.58 to 0.48) for early injection timings if fuel temperatures are high. The individual sprays of the 6-hole GDI injector may collapse into a uniform spray at high-density conditions without flash-boiling or under strongly flash-boiling conditions. The findings clarify the impact of ammonia’s high vapor pressure on injection mass and prove the relevance of different spray collapse mechanisms in ammonia direct injection engines.

Cavitation Phenomenon and Spray Atomization in Different Types of Diesel Engine Nozzles: A Systematic Review

<div>The high-pressure common rail fuel injection system for diesel engines is one of the core technologies that need to be addressed in the automobile industry. The control of the internal flow in multi-hole injector nozzles is the key to achieve accurate control of the fuel injection and spray process. There are various types of research on cavitation phenomena currently conducted on various types of test benches, but there is no conclusive discussion. Therefore, it is to summarize these studies in order to identify the highlights of existing studies and point out their shortcomings. This article compares and analyzes the developing patterns of cavitation phenomena on four test benches through literature review and has obtained rich research data on these four types of nozzles, but they still have their own shortcomings at the same time, even with numerical simulation. Based on this, the article has conducted a detailed and critical discussion on the current research situation and completed a summary. Specifically, it mainly involves four geometry parameters, two dynamic factors, and three fuel physical property parameters. The discussion conducted can contribute to the future development of cavitation models, further improving the energy-saving and -reducing emission reduction of diesel engines.</div>

Numerical characterization of high-pressure hydrogen jets for compression–ignition engines applying real gas thermodynamics

The development of hydrogen-fueled direct-injection compression–ignition engines requires adequate models that can accurately predict the spatial development and heat release rate of a jet at high pressure. It is found in literature that the combustion process benefits from minimizing flame–wall interaction, but it is unresearched how to achieve this. Jet theory can greatly reduce research efforts, only its validity is uncertain for hydrogen injections at relevant conditions. This work checks the validity via a parametric study performed with Computational Fluid Dynamics simulations. Sonic conditions are imposed at the nozzle exit, using different equations of state. It is found that real gas behavior needs to be used to compute these conditions and to model the jet dynamics. Furthermore, jet theory shows qualitative agreement with the simulation results. Finally, the heat release rate of a multi-hole injector appears insensitive to injection properties, but jet penetration can be controlled.

Characteristics and mechanism of the shift in condition- and time-dependent spray patterns induced by oxygenated fuel addition

As renewable energy sources, ethanol and butanol are usually added to fuels to reduce the fossil fuel consumption and soot emissions. Gasoline direct injection with multi-hole injectors provides accurate plume control, enabling ejection toward the desired location, while spray pattern shift leads to deviation in the injection direction. The spray shift needs to be modulated to realize the desired spray pattern, which is complicated by oxygenated fuel addition. To illustrate the shift induced by oxygenated fuel addition, numerical simulations and experimental studies were performed. The macroscopic and microscopic characteristics of the spray under various operating conditions were obtained via the diffuse backlight illumination and phase Doppler anemometry methods and the simulation of the internal three-phase flow. Moreover, typical single-component and binary fuels were employed to define the general envelope of the multi-component nature for auxiliary analysis. The shift in condition- and time-dependent spray patterns under both flashing and non-flashing conditions were illustrated. The spray morphologies were characterized by rectangular- and trapezoid-like trends. The addition of oxygenated fuels resulted in a smoother trend due to the change of the vapor pressure and surface tension of the mixed fuel. Moreover, it resulted in the variation of the critical width, which is crucial for the spray pattern shift. Additionally, the correlation between the critical width and ambient pressure was obtained. For the non-flashing spray, the internal flow and jet instabilities both influenced the spray width, and the correlation between gas ingestion and turbulence characteristics was obtained. This study aimed to provide guidance for better utilization of oxygenated fuels.

Experimental study of peripheral fuel injection for higher performance in diesel engines

In conventional diesel combustion (CDC), a centrally located multi-hole injector supplies fuel radially outwards. This study introduces and explores the concept of peripheral fuel injection (PeFI) to supply fuel from multiple locations on top of the combustion chamber using several single-hole injectors. The PeFI concept is designed to eliminate flame-wall and jet-wall interactions, and, ideally, to produce independent flames without any interference. PeFI is also intended to increase air entrainment in the near field and thus, reduce equivalence ratio at the lift-off length and subsequent soot formation. PeFI reduces wall heat transfer compared to CDC although this feature is not considered in the present study. The two methods of fuel injection are compared in a non-reacting optical chamber via high-speed imaging of the jets. N-heptane fuel at 1500 bar supply pressures is injected into a test chamber filled with nitrogen at engine relevant ambient densities of 23.0 and 18.5 kg/m3. Four configurations are trialed including a six-hole central injector and six, single-hole PeFI injectors with holes oriented at a layout angle, defined as the angle between the center of the fuel jet and chamber radius, of 0°, 15°, and 30°. Flow visualizations show jet-to-jet interactions at small layout angles for PeFI, but little to no jet-to-jet (or jet-wall) interference as the layout angle increases to 30°. Image analysis reveals that PeFI provides faster rate of injection, longer jet penetration length, greater width near the jet tip, and larger jet volume compared to those for the central injector. Overall, results demonstrate the potential of PeFI to simultaneously improve fuel efficiency and reduce emissions in diesel engines.

Combustion characteristics of oxymethylene dimethyl ether-diesel blends: An experimental investigation using a constant-volume combustion chamber

The combustion characteristics of oxymethylene dimethyl ether (OMEx) and its blends with diesel have been investigated using a multi-hole injector in a constant-volume combustion chamber. The results show OMEx addition can reduce the ignition delay, especially when blends of more than 50 vol% are used, at low chamber temperature. Two individual heat-release peaks are observed for OMEx during premixed combustion at 750 K, due to a pronounced low-temperature heat-release phase. The chamber temperature of 800 K can be regarded as a transition point for the behavior of burn duration as well as maximum ROHR peak, mostly caused by combustion regime transition from premixed- to diffusion combustion. It appears that there is an approximate linear relation between maximum ROHR peak and the time at which this peak occurs with injection pressure. The ignition delay of OMEx is almost insensitive to a decrease in ambient oxygen concentration. And the premixed ROHR profile, due to its high oxygen content, is very similar and only ignition delay and burn duration increase slightly. Additionally, comparisons of natural luminosity results for OMEx and diesel indicate that OMEx produces near-zero soot values. Luminosity is expected to be caused by chemiluminescence alone, which increases with injection pressure.

Near-field plume-to-plume interaction of multi-hole GDI injector under elevated ambient density conditions

Spray collapse can occur in the multi-hole injector under elevated ambient density conditions due to the plume-to-plume interaction. Numerous studies have investigated spray collapse in high ambient density conditions, but limited literature is available regarding the near-field plume-to-plume interaction triggering the spray collapse due to the optical density of the spray in the near field. In this study, an X-ray phase-contrast imaging (XPCI) technique that can visualize the spray structure and dynamics in the near field is applied to resolve the optical difficulties. With this method, the plume-to-plume interaction of a multi-hole gasoline direct injection injector is analyzed by measuring the transverse spray droplet size and axial velocity distributions under various ambient densities and injection pressures. The results showed that in the high ambient density condition with the low injection pressure, the spray droplet size started to increase, and the axial velocity remained stagnant from around 3 mm axial location as a result of plume-to-plume interaction and following spray collapse. The region of large droplets appeared asymmetric based on the hole arrangement. As the injection pressure increased in the high ambient density condition, the plume-to-plume interaction was suppressed in the near field and the spray collapse appeared farther downstream. Through the results, the spray collapse phenomenon and associated mechanism in the near field were discussed considering the droplet collision/coalescence and pressure structure in the spray.

Study of hybrid fuel injectors for aircraft engines

This project is based on the fuel injectors initially; a multi-hole injector is designed and then the single-hole injector is attached andconverted to a hybrid injector, which is the hybrid combination of multi-hole and single-hole injector which could be controlled electrically.All these processes are done with software. Solid works is used for designing and ANSYS is used for analysis of the 3D model. The massflow rate, pressure and velocity through the inlet and outlet is better when compared to other nozzles. This hybrid fuel injector hasthe added advantage of good atomization, providing better nozzle combustion. Then, the nozzle is used to operate a range of fuels,including JETA, kerosene, gasoline, diesel, and cryogenic fuel. Using the nozzle, each fuel exhibits various properties in terms of pressureand velocity. The designs are subjected to fluid flow simulation using ANSYS. Particularly, the liquid fuel are injected with very highpressure and velocity in order to atomize the fuel to form a homogeneous combustion. The present design is done for low viscous fue

Wetting front migration model of ion-adsorption rare earth during the multi-hole unsaturated liquid injection

In the process of ion-adsorption rare earth ore leaching, the migration characteristics of the wetting front in multi-hole injection holes and the influence of wetting front intersection effect on the migration distance of wetting fronts are still unclear. Besides, wetting front migration distance and leaching time are usually required to optimize the leaching process. In this study, wetting front migration tests of ion-adsorption rare earth ores during the multi-hole fluid injection (the spacing between injection holes was 10 cm, 12 cm and 14 cm) and single-hole fluid injection were completed under the constant water head height. At the pre-intersection stage, the wetting front migration laws of ion-adsorption rare earth ores during the multi-hole fluid injection and single-hole fluid injection were identical. At the post-intersection stage, the intersection accelerated the wetting front migration. By using the Darcy's law, the intersection effect of wetting fronts during the multi-hole liquid injection was transformed into the water head height directly above the intersection. Finally, based on the Green-Ampt model, a wetting front migration model of ion-adsorption rare earth ores during the multi-hole unsaturated liquid injection was established. Error analysis results showed that the proposed model can accurately simulate the infiltration process under experimental conditions. The research results enrich the infiltration law and theory of ion-adsorption rare earth ores during the multi-hole liquid injection, and this study provides a scientific basis for optimizing the liquid injection well pattern parameters of ion-adsorption rare earth in situ leaching in the future.

Very low soot formation with modulated liquid length and lift-off length of diesel spray flame

The vehicle diesel engine has entered the ultra-high injection pressure era. In order to study the spray and combustion characteristics under ultra-high pressure, the liquid length and combustion characteristics of multi-hole injectors (10 holes) with different hole diameters and different injection pressures were studied via experimental methods. The results show that increasing the injection pressure can effectively increase the slope of liquid length, while the hole diameter has little effect on it. However, during the stable stage, increasing hole diameter increase the liquid length, while the injection pressure has little effect on it. Different from the liquid length, the lift-off length during the stable stage is mainly affected by the injection pressure. F. Dos Santos’ model and the parameters of Siebers can more accurately predict the liquid length and lift-off length, even if the injection pressure has been increased to 300 MPa. Increasing injection pressure and reducing hole diameter can reduce the interference between liquid length and lift-off length. When the liquid length is less than the lift-off length, it can effectively inhibit soot formation. The value of LL/LOL has a fine linear relationship with stoichiometric air percentage. An equation of the relationship between the injection pressure and the hole diameter was established by the predicted model. Using this equation, we can get the range of LL/LOL less than 1 under different hole diameters or different injection pressures. The determination of this equation provides guidance and suggestions for the selection of hole diameters and injection pressure for diesel engines.

Investigations on the Diesel Spray Characteristic and Tip Penetration Model of Multi-Hole Injector with Micro-Hole under Ultra-High Injection Pressure

Increasing the injection pressure has a significant impact on atomization and combustion characteristics. Spray tip penetration serves as a vital parameter for fuel injection control and engine structure design. However, a reliable spray tip penetration model for ultra-high-pressure injection is currently lacking. To address this gap, this study establishes a theoretical 0-dimensional model for spray tip penetration under ultra-high pressure (300 MPa) conditions. The model is based on the conservation of momentum and phenomenological models. The new model divides spray tip penetration into two stages: Pre-breakup and post-breakup, with fuel injection rate and spray cone angle used as model inputs. To validate the model, high-speed camera observations and constant-volume chamber experiments are conducted to investigate the spray characteristics. The results indicate that the new spray tip penetration model demonstrates improved predictive accuracy across all experimental conditions.

Numerical characterization of hydrogen under-expanded jets with a focus on Internal Combustion Engines applications

In the context of reducing carbon dioxide ([Formula: see text]) emissions, hydrogen is gaining momentum as a possible fuel for Internal Combustion Engines (ICEs). In-cylinder direct injections allow for a higher specific power density while enabling different levels of charge stratification. The high-pressure injection leads to the onset of under-expanded jets, characterized by complex patterns of shock waves and expansion fans. In ICEs simulations, such physics needs to be correctly solved to obtain a reliable assessment of the mixture formation. In this paper, the main features of hydrogen under-expanded jets are examined under the conditions typically found in turbocharged engines. Improved correlations are provided for the assessment of the Mach disk height and diameter, up to a Nozzle Pressure Ratio (NPR) equal to 60. The dependency of the hydrogen-air mixing on the cylinder temperature has been analyzed, and the unsteady jet dynamics has been examined by continuously varying the combustion chamber pressure. To the authors’ knowledge, no studies of this kind can be found in the literature for the specific case of hydrogen. Lastly, a preliminary investigation of the jet-jet interaction (a Coanda-like effect) is reported. This phenomenon is observable when multi-hole injectors are employed, and it may have a great impact on the mixture formation.

MODIFICATION OF AMULTIHOLE INJECTOR TO A SINGLE-HOLE INJECTOR AND SPRAY CHARACTERISTICS OF THE MODIFIED INJECTOR BY TWO DIFFERENT IMAGING TECHNIQUES

In the present days, almost all the diesel engines are fitted with multihole injectors. Spray characterization of the injectors by different optical measurement techniques is very important to under-stand the air-fuel mixing and combustion procedure inside the cylinder. Instead of characterization of the dense sprays from a real multihole diesel injector, often a single plume is used to study the spray parameters. In the present work, spray characteristics are studied for a multihole injector with all nozzle holes open and with a single hole open conditions. Experiments have been conducted in a constant-volume, high-pressure, and high-temperature chamber with various injection pressures and at various ambient conditions. A high-pressure common rail injector with six holes is considered for the study. The penetration and cone angle of the spray from each hole are measured, and the hole-to-hole variation is studied. It has been observed that hole-to-hole variations with respect to spray penetration are prominent in low chamber pressures and injection pressures at the initial stage of injection, though they are minimal at later stages of injection. After that, five holes of the injector are blocked by microwelding, and the remaining single plume was studied and the results compared with the original multiplume spray. The study shows that the penetration length and cone angle of the single plume match well with that of the multiplumes at all chamber pressures and injection pressures. Later, the spray from the modified single-hole injector was characterized by two different imaging techniques, Mie scattering and diffused backlit imaging (DBI), to compare the penetration length and cone angle measured by the two imaging techniques. It is seen that the differences in penetration lengths by two imaging techniques are negligible, whereas the cone angles are greater in the case of backlit shadow imaging, particularly at higher temperatures.

Evaluation of multi-hole diesel injectors spray under evaporating conditions: Effects of adjacent spray plumes on the macroscopic and mixture characteristics of target spray

Previously, diesel sprays of multi-hole injectors were simulated in an environment where only a single spray plume was simulated. Although boundaries were declared as symmetry, the impact of aerodynamic forces between spray plumes was always neglected. In the present work, all spray plumes of diesel injectors are simulated in a cylindrical box mesh considering external effects including umbrella angle, space between nozzle holes, and hole length to hole diameter ratio. To examine the nozzle hole size effect, two 10-hole diesel injectors with hole diameters of 0.101 and 0.133 mm are investigated under 120 MPa injection pressure. Likewise, to understand the effect of injection pressure, the 0.101 mm hole diameter injector is studied under 120 and 140 MPa rail pressures. In experiments, Laser Absorption Scattering diagnostic technique is applied to visualize the vapor phase, measure mixture concentration and characterize air entrainment. Since Diesel fuel does not absorb UV light, Tracer fuel with the composition of 97.5% of n-tridecane and 2.5% α-Methylnaphthalene is used. On the contrary, sprays are simulated in the Eulerian-Lagrangian two-phase fluid framework using KHRT Breakup and Multicomponent Evaporation models. Parameters such as injection rate and initial spray trajectory angle are measured experimentally and used as input for the spray simulation. Computational results correspond with experiments particularly in terms of Penetration and Equivalence Ratio while Spray Angle deviates.

Effects of full transient Injection Rate and Initial Spray Trajectory Angle profiles on the CFD simulation of evaporating diesel sprays- comparison between singlehole and multi hole injectors

This paper investigates experimental and computational diesel sprays of single hole and multi hole injectors under vaporizing conditions. Two single hole and two ten-hole injectors with the same nozzle hole size are tested with the 120 MPa injection pressure. Experiments implement Laser Absorption Scattering technique. This method utilizes two wavelengths (Visible and Ultraviolet) of light and fuel's mixture concentrations are measured by attenuations of these lights. On the other hand, sprays are simulated in the Eulerian Langrangian two-phase fluid framework where KHRT and Multicomponent models are used as droplet breakup and evaporation models respectively. Full transient profiles of Injection Rate and Initial Spray Trajectory Angle are used as input boundary conditions for the spray simulation and effects on the spray characteristics are observed. Injection rates are measured with Bosch Long Tube and Initial Spray Trajectory Angles are extracted from the near nozzle field spray images. Experiments reveal that multi-hole injectors (0.101 mm and 0.133 mm) injectors depict longer liquid and shorter vapor penetrations. However, longer simulation liquid and vapor penetrations are seen for single hole injectors due to increased initial ramp-up phase. Sprays of Multi-hole injectors are diffused radially which promote air entrainment, better mixture formation, improved combustion, and lower exhaust emissions. Overall, simulated sprays using unfiltered injection rate profile as an input parameter showed an excellent agreement with experiments. While sprays using low-pass filtered injection rates showed a clear disagreement. Parameters including Liquid Length, Vapor Penetration and Evaporation ratios were found to be influenced by the IR profile rather than ISTA. Whereas vapor equivalence ratios depend on both input parameters plus breakup model constants.

Hole number effect on internal and discharged flow characteristics of diesel injector during transient operation

Selecting the proper number of nozzle holes is a critical matter to achieving optimal combustion in diesel engines. In recent years, short transient injections with ultra-high injection pressure have been adopted in diesel engines to achieve cleaner combustion but the effect of hole number on this transient diesel injection has not been thoroughly investigated. The current study performs an experimental observation of discharged flows from diesel injectors during transient operation using the X-ray phase-contrast imaging technique for six multi-hole injectors (three-, five-, six-, eight-, nine- and ten-hole). The observation results showed that discharged flows varied without any distinctive trends among the injectors. The largest spray dispersion angle and fastest velocity deceleration were observed in the 3-hole injector which showed an almost 3 times larger dispersion angle and 10% faster deceleration than the 10-hole injector. To understand possible factors governing such flow characteristics, three-dimensional internal flow simulations were conducted for the injectors. Unlike the results trend of discharged flows, the pressure and vorticity magnitude in the nozzle sac showed a linear change by altering the hole number. However, the hole-to-hole interaction of vortex flows varied in a complex way depending on the nozzle hole number. The nozzles with small and odd hole numbers, in general, showed a stronger hole-to-hole vortex interaction that can be the primary factor governing the discharged flow characteristics during the transient operation.

Investigation of near-field jet stability of a single-hole injector based on fast X-ray phase contrast imaging and image feature matching

Fuel spray is very effective in controlling the combustion process to improve engine performance and reduce emissions. Understanding the spray unstability during the injection process is of importance to improve the control of spray characteristics and engine operation. In this study, near-field biodiesel jets were recorded using fast X-ray phase contrast imaging and the flow features inside the jet were extracted using Speeded Up Robust Features (SURF) method. The image similarity by feature matching was successfully used to represent the near-field jet stability. Based on the jet stability, an injection process can be divided into five stages: an unstable stage at needle opening, a partially stable transition stage at needle opening, a stable stage, a stable transition stage at needle closing and an unstable stage at needle closing. The ranges of needle lift for five stages were also determined. The jet unstability is highly related to the cavitation formation and gas purging process during needle opening. The variation of stable jet feature is dependent on the needle lift at needle closing. Higher needle lift for the similar jet feature at needle opening indicates a hydraulic delay compared to needle closing. Finally, the possible reasons of jet feature formation and feature detection used on the multi-hole injector are discussed.

Experimental diesel spray characterization of the medium-duty injector with single- and multi-hole nozzle configurations under non-reacting, non-vaporizing conditions

Characteristics of diesel sprays injected through Cummins medium-duty ISB injectors were studied experimentally in an optically accessible constant-volume combustion vessel. The experiments were performed with ultra-low-sulfur diesel (ULSD) under non-reacting and non-vaporizing conditions, including different ambient gas densities (23–65 kg/m3), injection pressures (500–1,500 bar), and injection duration times (0.5–1.5 ms). The ambient temperature of the vessel was maintained at a room temperature of 313 K for all the tests. A systematic comparison was made between single-hole (SH) and multi-hole (MH) injector configurations. A plume-to-plume variation in spray penetration length was observed for various operating conditions. A substantial deviation was observed for a specific hole against the averaged plume, indicating that arbitrary selection of the plume index may result in inaccurate spray characterization of the MH injector. The penetration length of the MH injector was shorter than that of the SH injector under the same operating conditions, indicating that a spray model calibrated on SH injector data may not accurately predict the transient spray behavior of the MH injector in practical engine simulations. A square-root correlation of the spray penetration length was applied for both the SH and MH injectors. The spray penetration length and dispersion angles of the ISB SH injector were also compared with those of the heavy-duty Cummins ISX SH injector. While the ISX SH injector showed a faster penetration than the ISB SH injector, the dispersion angle was similar. The differences in spray penetration between ISB and ISX injectors followed the expected trend based on their nozzle hole diameters.

Influence of Jet on Aerosol Retention by Pool Scrubbing Under Multihole Injector

In severe nuclear power plant accidents, when the containment is in a serious challenging state, the gas mixture in the containment can be injected into the spent fuel pool through the multihole injector by the containment depressurization measure, to reduce the risk of containment overpressure failure and the release of radioactivity to the environment. The pool scrubbing efficiency of aerosol under the jet regime is studied on the small-scale aerosol pool scrubbing facility, focusing on the influence of mass flux, steam fraction, submergence, particle diameter, and pool initial temperature on the aerosol decontamination factor (DF). The results show that under the jet regime, the DF value is significantly greater than that in the bubble regime and the effect of jet flow on the mechanism of steam condensation and aerosol removal of the rising zone is weak under the conditions explored. DF increases with the increase of mass flux owing to the droplet interception and inertial collision aerosol removal mechanisms. Because the high pool temperature weakens the aerosol removal by steam condensation, DF decreases with the increase of initial pool temperature under the conditions explored. Based on the experimental data and the analysis of the removal mechanism under the jet regime, an empirical model of aerosol DF considering mass flux, steam fraction, pool temperature, submergence, and particle size is established and verified by the international experiments. The proposed model can be used to calculate DF in the process of containment overpressure discharge.

Distribution of Liquid Mass in Transient Sprays Measured Using Laser-Plasma-Driven X-Ray Tomography

We report, the use of laser-plasma-driven x rays to reveal the three-dimensional (3D) structure of a highly atomizing water spray. Soft x rays approximately 5 keV are generated by means of a laser-plasma accelerator. Transmission radiography measurements are performed at different angles, by rotating a multihole injector. Using computer tomography, the local liquid volume distribution and its spatial variation are retrieved in 3D, showing up to 55% liquid fraction at the nozzle outlet, which decreases to below 7% within only 1 mm. The resolution of the liquid volume fraction is 0.5% while the spatial resolution of the radiographic images is $11.5\phantom{\rule{0.2em}{0ex}}\ensuremath{\mu}\mathrm{m}$. The x-ray source used here provides successful measurements of liquid mass distribution over a relatively large volume and is very promising for the analysis of a variety of challenging transient spray systems, e.g., the injection of liquid synthetic and biofuels used for future clean-combustion applications.