Spray Mixing Research Articles

Large-Eddy Simulation of Laser-Ignited Direct Injection Gasoline Spray for Emission Control

Large-Eddy Simulations (LES) of a gasoline spray, where the mixture was ignited rapidly during or after injection, were performed in comparison to a previous experimental study with quantitative flame motion and soot formation data [SAE 2020-01-0291] and an accompanying Reynolds-Averaged Navier–Stokes (RANS) simulation at the same conditions. The present study reveals major shortcomings in common RANS combustion modeling practices that are significantly improved using LES at the conditions of the study, specifically for the phenomenon of rapid ignition in the highly turbulent, stratified mixture. At different ignition timings, benchmarks for the study include spray mixing and evaporation, flame propagation after ignition, and soot formation in rich mixtures. A comparison of the simulations and the experiments showed that the LES with Dynamic Structure turbulence were able to capture correctly the liquid penetration length, and to some extent, spray collapse demonstrated in the experiments. For early and intermediate ignition timings, the LES showed excellent agreement to the measurements in terms of flame structure, extent of flame penetration, and heat-release rate. However, RANS simulations (employing the common G-equation or well-stirred reactor) showed much too rapid flame spread and heat release, with connections to the predicted turbulent kinetic energy. With confidence in the LES for predicted mixture and flame motion, the predicted soot formation/oxidation was also compared to the experiments. The soot location was well captured in the LES, but the soot mass was largely underestimated using the empirical Hiroyasu model. An analysis of the predicted fuel–air mixture was used to explain different flame propagation speeds and soot production tendencies when varying ignition timing.

Preparation of IC21 Spherical Powders by PREP Process

The IC21 spherical powders with main content of Ni3Al were successfully manufactured by the high speed plasma rotating electrode process (HS-PREP). The powders particle size distribution fitted the mixed spraying model well. The chemical contents changes after melting were detected. The microstructure of the IC21 powders was formed by cellular crystal on the surface and dendrite inside, which was a typical PREP powder. The morphologies and properties of the irregular powders were also analyzed which indicated that the composition segregation and oxides inclusion of the electrode were the main reason for the formation. However, its proportion was less than 0.5%, which would not affect the additive manufacturing. The fundamental powder particle size distribution data for different rotating speeds was measured. The morphology and properties result show that the PREP could support qualified IC21 spherical powders with significant powder yields.

Experimental evaluation of parameters affecting the coating performance of urea seeds in a prototype bottom external mixing spray two-fluid nozzle fluidized bed granulator

A comparative study was carried out on coating and coalescence mechanisms of urea seeds by molten urea, using external mixing two-fluid nozzle fluidized bed granulator (FBG). In this regard, the variables influencing a new parameter defined as coating performance (CP) of urea granules were modeled. The variables included of spraying and atomizing air pressures, masses of loaded seeds and molten urea, and mass flow rate of fluidization air. Considering all interactions between the variables, the optimum conditions for obtaining the maximum 60% CP was determined. Furthermore, according to cumulative size distributions analyses, the conditions leading to proper size guide number (SGN) and uniformity index (UI) was characterized. The SEM observations showed that, in most cases, the porous initial urea seeds were coated by a compact molten urea layer. Considering the dimensionless Stokes numbers, the extent of fluidized particles’ velocity leading to domination of coating or coalescence was verified.

Supercontinuum-illumination for long-working-distance microscopic imaging of air–liquid mixed sprays in the near-nozzle region

We demonstrate the optical diagnosis of air–liquid mixed sprays in the near-nozzle region using the supercontinuum (SC)-illumination long-working-distance microscopic imaging method, enabling the imaging of microdroplets, ligament structures, and cavities. In addition, SC-illumination long-working-distance microscopic imaging effectively suppresses speckles and reveals the ligament structures in the sprays more accurately. Finally, analysis of the droplet size distribution of the sprays under different air and liquid flow rates indicates that SC-illumination long-working-distance microscopic imaging offers several advantages for studying spray dynamics at the small structure level.

Large-eddy simulation of spray assisted dual-fuel ignition under reactivity-controlled dynamic conditions

Here, a large-eddy simulation and a finite-rate chemistry solver (see Kahila et al. Combustion and Flame, 2019) is utilized to investigate diesel spray assisted ignition of a lean methane-air mixture. A compression heating model is utilized to emulate the ambient temperature and pressure increase in a compression ignition (CI) system. The key parameter is the start of injection (SOI) relative to a virtual top dead center (TDC), where the peak adiabatic compression pressure/temperature would be achieved. Altogether, five different cases are investigated by advancing the SOI further away from the TDC with constant injection duration. The main findings of the paper are as follows: 1) Advancing the SOI advances the ignition timing of the spray with respect to the TDC from 0.91 to 7.08 CAD. However, beyond a critical point, the ignition time starts retarding towards the TDC to 4.46 CAD due to the excessively diluted diesel spray. 2) Advancing the SOI increases the contribution of leaner mixtures to the heat release rate (HRR). Consequently, the low-temperature combustion HRR mode becomes more pronounced (from 33.9% to 76.7%) while the total HRR is reduced by a factor of 4. 3) Ignition is observed for all investigated SOI’s. However, the numerical findings indicate that advancing the SOI decreases the ignition kernel size, resulting in weaker ignition. 4) An ignition index analysis with frozen flow assumption indicates that for the SOI’s close to the TDC the HRR mode appears as spray mixing controlled, while for advanced SOI it becomes reactivity controlled, dominated by fuel stratification.

Management of Hypsipyla robusta Moore (Pyralidae) damage in Chukrasia tabularis A. Juss (Meliaceae)

Chukrasia tabularis is a high-value tree in the mahogany family and in Vietnam is grown in home gardens and small plantations. One to 3-year old trees are susceptible to shoot tip damage from larvae of Hypsipyla robusta which feed inside the stem. With the recent expansion of C. tabularis plantations, the forestry sector is seeking management options for this pest. Therefore, the efficacy of a range of commercial insecticides and biological agents were evaluated in nursery and plantation experiments. Twenty days after application of carbaryl, carbosulfan, deltamethrin or fipronil to the shoots of 1-year old nursery seedlings, damage from inoculated H. robusta was reduced by 83–100%. Application of Bacillus thuringiensis, Beauveria bassiana or Metarhizium anisopliae were less effective, reducing damage by 58, 33 and 42%, respectively. In 2-year old trees in the field, damage from natural H. robusta infestation was reduced by >75% at 30 days after application of carbaryl, carbosulfan, deltamethrin or fipronil. Including alkyl sulfonate or trisiloxane ethoxylate as adjuvants into the spray mix reduced damage by up to 98%. Soil applied fipronil granules and foliar-applied B. thuringiensis were less effective treatments (72 and 63%, respectively). The most effective treatments can now be evaluated in more extensive trials so that management protocols can be provided to end-users.

Spray Drying of Ginger and Physical and Micro Structural Properties of Spray Dried Ginger Powder - An Advance Food Material

The objective of this work was to optimize the spray drying of ginger juice using maltodextrin and to investigate the effect of carrier agent on physical and micro-structural properties of spray dried ginger powder. A laborator ypilot scale spray dryer was employed for spray drying process and commercial maltodextrin was used as carrier agents. Ginger powder obtained under optimized condition of maltodxtrin concentration and 165oC inlet temperature was evaluated for moisture content, water activity, particle size distribution, bulk density, true density, porosity, wettability flowability, dispersibility, and powder morphology. Micro-structural analysis revealed powder particles of various sizes and shapes however properties were within the desired range. Spray dried ginger powder can be used as natural ginger flavouring. Optimized spray drying parameters and powder properties pave the way for testing high sticky food material and mixing of different spray dried powders by surface modification for more advance powder processing.

Numerical study on turbulent dispersion of diesel sprays under ultrahigh injection pressure using large eddy simulation

ABSTRACT The modern diesel engines equipped with an advanced fuel injection system up to ultrahigh injection pressure of 300 MPa are under development at present. The impact of injection pressure on fuel spray characteristics such as spray penetration and spray cone angle has been widely concerned in previous studies. However, it is still lack of the detailed investigation on the turbulent dispersion of small droplets produced by a high-pressure injector due to the limited capability of optical diagnostic techniques to simultaneously measure the two phases. Droplet dispersion due to turbulence plays a major role in high-velocity fuel spray mixing and combustion processes involving group evaporation of droplets. Thus, the effect of different injection pressures on droplet dispersion in nonevaporating diesel sprays was investigated using the Euler-Lagrange framework with large eddy simulation (LES) implemented in an open-source code OpenFOAM. Size-dependent instantaneous radial motion and dispersion characteristics of droplets dominated by large-scale turbulent structures within a polydisperse downstream spray were analyzed in detail. Results show that increasing injection pressure can modestly promote the radial dispersion of most droplets with diameter of 2 ~ 12 µm further downstream at the late stage of injection. This could be the result of the increasing interaction time of droplets with larger turbulent structures due to the increase of spray penetration with increasing injection pressure. However, increasing injection pressure has no significant impact on the strength of droplet-turbulence interaction in terms of slip velocity between droplet and gas phases and this could be quantitatively explained by the droplet Stokes number (St) estimated in this study. The most droplets with 0.1 < St < 10 tend to move and concentrate further radially outward, leading to droplet clustering. Thus, the effect of injection pressure on droplet-turbulence interaction is much less than its influence on droplet size for high-velocity fuel sprays, indicating that the ultrahigh injection pressure has much less important impact on the spatial inhomogeneity of droplet distribution than its influence on the evaporation rate of individual droplets.

Optimization of microencapsulation of selenium with gum Arabian/Persian mixtures by solvent evaporation method using response surface methodology (RSM): soybean oil fortification and oxidation indices

Optimization of microencapsulation of sodium selenite 100–900 mg with a combination of Arabian gum 25–29% and Persian gum 5–1% per 20 ml mix spray solution by a solvent evaporation method using response surface methodology with central composite design (α = 2 with 6 central points and 2 repetition in axial and factorial points) were investigated. This study aimed to production of microencapsulated selenium with the highest encapsulation efficiency (EE) and the smallest particle-size for increasing soybean-oil shelf life against oxidation. The optimal-formula-1 (135 mg Na-selenite, Arabian to Persian gum ratio 9) with an actual EE of 77.35% and particle-size of 48.20 μm and the optimal-formula-2 (109 mg Na-selenite, Arabian to Persian gum ratio 14) with an actual EE of 93.74% and particle-size of 45.20 μm produced. Consequently, the un-microencapsulated sodium-selenite (8.6 ppm of sodium-selenite, equivalent to 3.93 ppm pure selenium, regarding recommended daily intake of 55 μg for Selenium and 14 g for oil), the two selected optimal formulas (containing 8.6 ppm sodium-selenite, i.e., 3.92 ppm pure selenium), the BHA (200 ppm), were added to refined antioxidant-free soybean oil (as a control treatment) and then were placed at the 55 °C for (0, 23, 46 days) equaled to 20 °C (0, 180, 360 days) by a shelf-life accelerator program. The oxidation indices including, total acid number, peroxide value, thiobarbituric acid value, para-Anisidine value, and Totox value as well as, antioxidant activity in soybean-oil over a 1-year storage-time at 20 °C showed the order of the proposed treatments were included 482 ppm optimal-formula-2 ≥ 391 ppm optimal-formula-1 ≥ 200 ppm BHA > 8.6 ppm un-microencapsulated Na-selenite > blank treatments. Optimization of selenium microencapsulation process using Arabian-Persian gum profile and different amounts of sodium slenite by RSM (Part 1) and Assessment of the oxidation indices in refined antioxidant-free soybean oil containing microencapsulated optimal formulas in 365-day storage time at 20 °C (Part 2)

Phase-selective laser–induced breakdown spectroscopy in flame spray pyrolysis for iron oxide nanoparticle synthesis

The flame spray pyrolysis of iron oxide nanoparticles using the new reference nozzle SpraySyn is a key step towards the understanding of the coupling of physicochemical steps such as precursor atomization, spray evaporation, combustion, particle formation and growth. Owing to the countless available solvents and precursors, systematic investigations are necessary to fully understand the impact of precursor formulation on the reaction route and, hence, the particle properties. In this work, the recently developed phase-selective laser-induced breakdown spectroscopy (PS-LIBS) technique is applied to an external mixing spray flame reactor in order to study iron oxide particle formation along the axial centerline of the spray under varying precursor solutions. The addition of 2-ethylhexanoic acid (EHA) to precursors is investigated and significant differences in the evolution of the atomic emission spectra are observed, enabling the differentiation between droplet-to-particle and gas-to-particle routes in situ. The observations from PS-LIBS are in good agreement with TEM images and XRD, where haematite (α-Fe2O3), maghemite (γ-Fe2O3), and magnetite (Fe3O4) were observed. Raman spectroscopy (RS) in particle-free spray-flames revealed a significant gas-phase temperature difference of about ΔT∼500 K under addition of EHA to the spray and demonstrated accurate temperature measurements up to droplet rates of 103 Hz. The experimental results allow deep insights into the spray flame combustion and particle nucleation kinetics. Moreover, they can be coupled with population balance models and be used for the validation of numerical simulations.

An Analysis on the Effects of the Fuel Injection Rate Shape of the Diesel Spray Mixing Process Using a Numerical Simulation

In diesel engines, fuel mixing is an important process in determining the combustion efficiency and emissions level. One of the measures used to achieve fuel mixing is controlling the nature and behavior of the fuel spray by shaping the injection rate. The mechanism underlying the behavior of the spray with varying injection rates before the start of combustion is not fully understood. Therefore, in this research, the fuel injection rate shape is investigated to assess the spraying and mixing behavior. Diesel sprays with different ambient temperatures and injection pressures are modeled using the CONVERGE-CFD software. The validation is performed based on experimental data from an Engine Combustion Network (ECN). The verified models are then used to analyze the characteristics of the diesel spray before and after the end-of-injection (EOI) with four fuel injection rate shapes, including a rectangular injection rate shape (RECT), a quick increase gradual decrease injection rate shape (QIGD), a gradual increase gradual decrease injection rate shape (GIGD), and a gradual increase quick decrease injection rate shape (GIQD). The spray vapor penetrations, liquid lengths, evaporation ratios, Sauter mean diameter (SMDs), distributions of turbulence kinetic energy, temperatures, and equivalence ratios were compared under different injection rate shapes. The results show that the QIGD injection rate shape can enhance mixing during injection, while the GIQD injection rate shape can achieve better mixing after the EOI.

Nozzle rate of injection estimation from hole to hole momentum flux data with different fossil and renewable fuels

Due to environmental problems, research on fuel economy and pollutant emissions in internal combustion engines has drawn the attention of automobile manufacturers and researchers. The diesel engine is one of the most efficient alternatives and one of the main areas of the study in these engines is spray mixing, recognized as a critical factor in combustion control and the reduction of its related contaminants.The studies about fuel sprays rely on experimental data of the rate of injection, which can only be obtained with high-cost equipment. The aim of this paper is to validate for different fuels a method for the determination of the rate of injection based on spray momentum measurements and the total injected mass. After a proper tuning of the test momentum flux device, the injection rate results were validated using the Bosch tube method. The technique was validated for four different fuels, diesel, biodiesel, GTL (Gas-to-liquid) and Farnesane, in order to identify the consequences of the fuel properties on the injection performance characteristics and the estimation method.The results of rate of injection following the procedures presented showed good accuracy when compared to experimental values. These methods can be employed to estimate this parameter when experimental facilities for this purpose are not available.

Simulation and experimental investigation of swirl-loop scavenging in two-stroke diesel engine with two poppet valves

Scavenging is becoming one of the determinants of two-stroke engine performance. Efficiency of U-type loop scavenging of two-stroke diesel engine with two poppet valves is generally unsatisfactory due to scavenging short-circuiting and large amount of residual burned gas in cylinder, and it is hard to generate the swirl that facilitates fuel spray mixing and combustion. In order to deal with the above issues, a swirl-loop scavenging configuration is proposed to involve swirl and depress short-circuiting. To investigate swirl-loop scavenging performance, this article simulates the scavenging process by numerical method, optimizes the tracer gas method to measure and evaluate the scavenging performance, as well as analyzes the influence factors. The results demonstrate that, compared with U-type loop scavenging, the trapping efficiency and scavenging efficiency of swirl-loop scavenging respectively increase by 8% and 10%. Change of engine speed has an impact on the delivery ratio and trapping efficiency but load does not. Both intake and exhaust valve timings affect scavenging performance and short-circuiting to a large extent. In addition, the accuracy of tracer gas method in measurement of scavenging performance parameters is improved, and the scavenging efficiency deviation between simulation and experiment is decreased from 6% to 2%.

An experimental study of a very high-pressure diesel injector (up to 5000 bar) by means of optical diagnostics

The aim of this work is to investigate a novel very high-pressure diesel injector under different working conditions. Furthermore, the aim of this work is also to analyse the behaviour of the evaporation, mixing and combustion of a diesel spray in a quiescent environment at very high injection pressures. In order to achieve this, the injector was first characterized from 2500 bar to 4000 bar of injection pressure. Then, an experimental matrix was designed to study the high-pressure spray under (i) cold non-evaporating, (ii) evaporating non-reactive and (iii) reactive conditions under different injection pressures up to 5000 bar. The experiments were carried out in a constant volume cell equipped with optical accesses. This allowed the application of the schlieren, mie-scattering and OH* chemiluminescence techniques at high speed to quantify the propagation of the spray through the ambient gases. The injector used was a prototype single-hole axial injector working with reference diesel as the injection fluid. The results showed a strong dependency of the spray tip penetration on the injection pressure. In some conditions creating shock waves inside the chamber that would disrupt the spray flow, causing it to mix better. Although the higher exit velocities made the fuel travel faster, resulting in longer penetrations of both phases, it also caused the fuel to evaporate faster due to slightly better mixing, resulting in similar liquid length values. This increased momentum enhanced mixing, resulting also in shorter ignition delay times. The higher velocities caused the flame base to stabilise further from the nozzle, which led to longer lift-off lengths.

Diagnosis of liquid-gas mixed sprays in the near-field region using femtosecond laser induced supercontinuum imaging method.

Direct femtosecond shadowgraphy and supercontinuum (SC)-illumination imaging methods for diagnosing liquid-gas mixed sprays in the near-field region of spray nozzles were compared. Some big spray structures can be captured using femtosecond shadowgraphy which can freeze the motion of the sprays. But the speckles caused by the interference of multi-scattered photons erode the edges of ligaments and conceal many fine droplets. SC-illumination imaging can not only freeze the motion of the sprays but also significantly suppressing the speckles, presenting a more realistic spray pattern. Based on the SC imaging technology, the effects of various factors such as flow ratio of gas to liquid (GLR), total flow and nozzle size on the spray were studied.

Quantifying Spray Deposition from a UAV Configured for Spot Spray Applications to Individual Plants

HighlightsSpot spraying is a method for applying pesticides to individual tree crowns.A new method is presented to quantify and analyze the two-dimensional spot spray deposit pattern produced by a UAV.A bivariate normal distribution provided a good fit to the observed deposition data for all treatments.Model parameters effectively described the shape of the ground deposits.Abstract. The purpose of this study was to develop a method for quantifying and analyzing the two-dimensional spray deposit pattern produced from a UAV spot spraying system for applying pesticides to individual plants with crown diameters in the range of 1 to 2 m. An XAG P20 UAV was flown over the center of a sampling grid, and spray deposits from three droplet size treatments, with nominal volume median diameters (VMDs) of 335, 430, and 1150 µm, were measured using horizontal steel plate collectors placed on blocks on the ground. A colorimetric tracer in the spray mix was used to quantify spray deposition. The positioning accuracy of the UAV was excellent, but the droplet sizes produced were much larger than expected. A bivariate normal distribution provided a good fit to the observed deposition data for all treatments. Model parameters effectively described the shape of the ground deposits. Displacement of the deposit distribution center was in a downwind direction. While there were no statistically significant effects of wind speed on the shape or degree of displacement of the center of mass of the observed ground deposit pattern, this was probably a result of the low wind speeds during the study, which were often close to or below the lower sensitivity threshold of the anemometer used. The actual spray coverage on a 2 m tall artificial tree target of 1 or 2 m diameter placed in the center of the plot was consistent across the range of droplet sizes and operating conditions tested. Nevertheless, it is hypothesized that targeting could be further improved if the UAV was slightly offset in an upwind direction and, conceptually, the degree of this displacement would increase as wind speed increased. A sampling grid spacing of 1.0 m would have produced results similar to the 0.5 m spacing actually used. Keywords: Aerial spraying, Pesticides, Spot spraying, Spray deposition, UAV, Unmanned aerial vehicle.

Study on the selection of vegetation for ecological restoration of residual soil slopes in South China

Vegetation selection is one of the key contents of slope ecological restoration, based on the characteristics of climate and soil in South China and the principle of local conditions, this paper studies the selection of vegetation in the ecological restoration project of the residual soil slope. The typical herbs, shrubs and trees suitable for the area are determined by theoretical analysis. At the same time, through field tests, the growth and development of vegetation after the spraying are monitored for a long time, and the interaction relationship between vegetation community after multiple vegetation mix-ups is analyzed. The results show that plant selection should avoid the choice of a single plant, and should try to achieve complementary coordination between species. At the same time, when taking a variety of plant mixing spray, the configuration ratio of different plants should be determined according to the growth cycle of different plants and the results of indoor ratio test, so as to avoid mutual interference.

Adjuvants plus phytosanitary products and the effects on the physical-chemical properties of the spray liquids

The frequent tank mixing of phytosanitary products, adjuvants, and foliar fertilizers highlights the lack of information which sustains decisions about what products can be mixed for spray application. Thus, the aim of this study was to evaluate the physical and chemical characteristics of fungicides, herbicides, and insecticides in combination with some adjuvants on the Brazilian market. The experimental design was completely randomized and spray mixes of the phytosanitary products: fungicide (azoxystrobin+benzovindiflupir), herbicide (diamônio salt of N-(phosponomethyl)) or insecticide (fenpropathrin) were evaluated in combination with adjuvants (mineral oil base, foliar fertilizer or lecithin + propionic acid), and in two application rates (95 and 52 L ha-1); all with four replications. Surface tension, electrical conductivity, pH, dynamic viscosity and density of spray mixes were evaluated. The adjuvants presented characteristics capable of significantly altering the physicochemical properties of the phytosanitary spray mixes, and thus, alter the biological effectiveness and efficiency of the spray applications. However, its effects are also dependent on the phytosanitary product added to the spray mix, which makes general recommendations a difficult task. The greatest pH reduction, as well as the greatest increase in electrical conductivity, were caused by the adjuvant lecithin + propionic acid. All phytosanitary products and adjuvants studied, associated or not, resulted in a reduction in the surface tension of the spray mix in relation to water. The magnitude of change of density and dynamic viscosity promoted by adjuvants was lower than the other characteristics evaluated.

The association of self-reported respiratory system diseases with farming activity among farmers of greenhouse vegetables.

ObjectivesSeveral studies have investigated the link between agricultural activities of open-field farmers and the prevalence of respiratory diseases, but the relationship with greenhouse vegetable farmers remains unclear.MethodsA total of 1,366 participants from four villages in China provided information about their agricultural activities and symptoms of diagnosed respiratory system diseases. The Poisson regression model and zero-inflated Poisson regression model were used to assess the association between diseases, symptoms, and agricultural activities.ResultsThe prevalence of respiratory diseases was 3.59%, and the rates of four main symptoms (cough, tachypnea, chest distress, and hemoptysis) were 17.21%, 8.56%, 10.25%, and 1.61%, respectively. Mix spray of pesticides associated with cough, tachypnea and chest distress, 1.740-, 3.385- and 2.882-fold likelihood were found than hand spray, and the significant association were detected in empty, general information, life-style information adjusted models.ConclusionsThe relationship between agricultural activities and respiratory diseases is unclear. However, use of the mix spray method of pesticide application may increase the risk of cough, tachypnea, and chest distress.

Simulation of Liquid and Gas Phase Characteristics of Aerated-Liquid Jets in Quiescent and Cross Flow Conditions

The simulation of the liquid- and gas-phase properties of aerated-liquid jets in various quiescent and cross flow conditions are presented in the study. For simplicity, water is used as the liquid for all test conditions. The effect of various air-to-liquid ratios under super-sonic cross flow conditions are simulated and compared to experimental conditions, which is taken in the supersonic wind tunnel with a dimension of 762 × 152 × 127 mm. An injector with an orifice diameter of 0.5 mm is used both in a non-aerated and aerated injection into a supersonic cross flow prescribed by the momentum flux ratio of the liquid jet to free stream air, q0. The initial conditions of the spray calculation were estimated from internal flow simulation using VOF and X-ray data. The conservation-element and solution-element (CE/SE) method, a novel numerical framework for general conservation law, is applied to simulate the compressible flow. The effect of degree of aeration, breakup, and mixing of the liquid spray are demonstrated. The spray penetration height and average droplet size along with a spray penetration axis are quantitatively compared with data. The shock train flow structures induced by the presence of a liquid jet are further discussed.