Injection Mode Research Articles

High-power narrow-linewidth tunable blue laser diode array utilizing a blazed grating external cavity

High-power, narrow-linewidth blue laser sources have been in high demand for applications in laser pumping and spectral beam combining. In this paper, a blue laser source, consisting of 12 transistor-outline (TO) packaged laser diodes (LD), is established through space beam combining. An improved external cavity (EC) utilizing a blazed grating (BG), a beam splitter, and a beam expander is investigated. Through injection feedback and mode competition, a laser output, with 31.2 W power, 445.04 nm central wavelength, 0.18 nm full-width at half maximum (FWHM) linewidth, is achieved at a driving current of 3.0 A. A tunable range of 3.6 nm is observed at 2.0 A driving current. Additionally, the effect of the deformation of the aluminum-coated grating under a high-intensity blue laser is examined. The external cavity requires a moderately efficient blazed grating and prevents potential damage caused by high absorption and thermal stress concentration. The system exhibits excellent temporal stability in both output power and spectrum. Moreover, wavelength-locking experiments using both a volume Bragg grating (VBG) and a surface grating (SG) are conducted to serve as comparative tests for this study. Compared with volume Bragg gratings, blazed gratings offer spectral tunability and are insensitive to temperature perturbations and mechanical stress. Compared with surface gratings, blazed gratings offer a relatively high threshold and stable performance at high driving currents. Furthermore, blazed gratings are more cost-effective than VBGs, providing a competitive advantage. To the best of our knowledge, it’s the first blue laser source with over 30 W output and 0.18 nm FWHM linewidth utilizing a blazed grating external cavity.

Sub-volt forward-biased silicon microring modulator at 210 Gb/s.

Low-voltage and efficient optical modulators in the silicon photonic (SiPh) platform are highly desired for realizing high-speed connectivity in chip level interconnects, data center interconnects, and high-performance computing (HPC). With the modulator operating at CMOS compatible voltages, high-voltage modulator drivers are no longer needed, thus reducing driver design complexity and power consumption. We demonstrate a silicon microring modulator (MRM) operating at a driving voltage of 0.8 Vpp. We achieve high modulation efficiency by using a small forward bias of 0.2 V: the forward bias voltage allows the modulator to have an enhanced optical modulation amplitude (OMA) by operating near injection mode, modulating 180 Gb/s (180 Gbaud) non-return-to-zero (NRZ) and 210 Gb/s (105 Gbaud) 4-level pulse amplitude modulation (PAM-4) free of electrical or optical amplification. We also demonstrate the operation at zero bias and achieve up to 200 Gb/s. Error-free operation was observed at 130 Gb/s (NRZ). The absence of an external biasing voltage can further improve energy efficiency and simplifies device integration.

Supercritical fluid chromatography for milligram preparation of enantiomers.

Preparative chromatographic enantioseparation is now the preferred technique for obtaining milligram quantities of pure enantiomers in the initial phase of development of a therapeutic compound. Supercritical fluid chromatography offers several advantages over liquid chromatography and was therefore selected for the preparative enantioseparation of a new potential anti-inflammatory molecule. Approximately 10mg of each of the two enantiomers was successfully prepared using a Chiralpak AD-H (tris-3,5-dimethylphenylcarbamate of amylose) polysaccharide-based stationary phase with 40% of ethanol as a co-solvent, using a stacked injection mode. A peak distortion was observed during volume overloading, which may be due to the mixed-stream injection method.

Large eddy simulation study: The impact of fuel injection modes on the dynamic performance of low-emission tower-type coaxial-staged combustor

The low-emission technology of gas turbine combustors is currently an active area of research. In light-duty lean-premixed combustors, achieving rapid and uniform fuel mixing presents significant challenges. Additionally, combustion instability issues are also likely to occur. To address these challenges, large eddy simulation and the flamelet generation manifold combustion model are used to predict the velocity field, fuel distribution, vortex structure, flame structure, and flame liftoff phenomenon in a low-emission tower-type coaxial-staged combustor. The results indicate that variations in the position of the fuel holes in the second main stage result in two types of fuel injection modes: coupling and decoupling. These variations do not significantly influence the velocity and vortex structure in a non-reacting flow. The dominant frequency of the non-reacting flow field in the combustor is 810 Hz. The position of the precessing vortex core affects the distribution of fuel. Furthermore, the uniformity of fuel distribution at the outlet of the second main stage is notably affected by different fuel injection modes. The spatial distribution of fuel is more uniform. In the reacting flow, compared to the decoupling mode, the fuel expansion angle decreases by 4.5° under the coupling mode, and the heat release at the flame front is more intense. Additionally, it is found that fuel injection modes significantly influence the dynamic characteristics at the flame root. Better flame stability is observed under the decoupling mode, while flame liftoff phenomena occur under the coupling mode. The lifted flame root shifts downstream by 12.3 mm.

Performance study of an innovative dual injection mode injector for marine low-speed dual-fuel engine

Marine low-speed dual-fuel engines typically have two sets of fuel injection system, main-injection and micro-injection. In order to make the fuel injection system of marine low-speed dual-fuel engine compact in structure and flexible in injection control, an innovative dual injection mode injector (DIMI) which can achieve both the functions of main-injection and micro-injection was proposed. The switching between main-injection and micro-injection mode of the injector is achieved through the collaborative control of dual solenoid valves. Based on the constructed AMESim model, the injection quantity characteristic and hydraulic efficiency of the DIMI were investigated under different working conditions and injection modes. The results show that, when the DIMI in main-injection mode achieves injection quantity characteristic similar to those of a traditional electronically controlled injector (TECI), the electromagnetic forces of solenoid valves of the DIMI are less required to 80% of that of the TECI, and the fuel return quantity and hydraulic efficiency of the DIMI are comparable to those of the TECI under the same working conditions. By changing the minimum limit height of the needle of the DIMI under micro-injection mode, different ranges of micro-injection quantity could be designed according to the requirements of the engine, and the control accuracy of injection pulse width (IPW) on micro-injection quantity is higher than on main-injection quantity. Both the hydraulic efficiency of the DIMI under main-injection and micro-injection mode increase with the rail pressure and IPW in the small IPW range, then gradually tend to be saturated with the increase of IPW. As the minimum limit height of the needle increases, the injection quantity and hydraulic efficiency of the DIMI under micro-injection mode increases overall, however, the saturation values of the hydraulic efficiency in micro-injection mode under different needle minimum limit heights are still smaller than those in main-injection mode.

Evaluating the potential of hydrophilic interaction liquid chromatography for collagen peptide mapping analysis

This study presents a systematic approach for developing an innovative hydrophilic interaction liquid chromatography (HILIC) method for collagen peptide mapping analysis. The predominant post-translational modification (PTM) of collagen, proline hydroxylation, introduces polar hydroxyl groups throughout the collagen sequence, making HILIC a promising alternative to classical reversed-phase liquid chromatography (RPLC) approaches. This study employs sixteen model peptides, selected from in silico predicted tryptic peptides with zero missed cleavages and representing diverse physicochemical properties and structural motifs of collagen. The peptides were used as standards to conduct detailed chromatographic evaluation. Various HILIC stationary phases and mobile phases were systematically examined to identify optimal separation conditions for collagen peptides, contributing to a better understanding of peptide behavior in HILIC. The study also explores the effects of sample diluent and injection mode, comparing classical injection with the Performance Optimizing Injection Sequence (POISe), to determine their impact on HILIC performance. Introducing a plug of weak solvent (acetonitrile) prior to sample injection, effectively mitigates the mismatch in eluent strength between the fully aqueous sample diluent (resulting from tryptic digestion) and the mobile phase, addressing issues of peak distortion. Different injection volumes (from 0.5 to 8 µL) and acetonitrile ratios (1:1, 1:2, 1:5 and 1:10) were tested to optimize sample injection and increase sensitivity of collagen tryptic peptides.Following method optimization, HILIC was coupled with mass spectrometry (MS) to evaluate its effectiveness in analyzing collagen-digested samples. This evaluation included the assessment of peptide sequence coverage and the method ability to identify hydroxylation patterns, thereby demonstrating its potential for detailed peptide analysis.

Combustion characteristics of methanol engine applying TJI-HPDI with optimized pre-chamber nozzle structure under different injection and spark strategy

Methanol fuel faces challenges in achieving mixing controlled combustion (MCC) due to its low cetane number. This study proposes utilizing turbulent jet ignition to facilitate methanol MCC under high-pressure direct injection mode, namely TJI-HPDI. Three coordination schemes were developed numerically based on the projection angles between hot jets and main methanol spray plumes axis: opposing (Base design), opposing staggered (Design 1), and circumferential staggered interference (Design 2). Varied orifice diameters was employed to regulate jet energy and velocity. The results indicated that Design 2-BSB (Big-Small-Big orifice) scheme exhibited superior combustion and emission performance. Furthermore, the impact of start of main injection timing (SOI) on ignition and combustion characteristics was investigated under this scheme. An SOI of −12 °CA after top dead center (TDC), creating a 7 °CA interval between spark and SOI timing, achieved optimal ITE by minimizing the duration of CA10-CA50 and optimization methanol mixture distribution around hot jets. Additionally, pre-chamber (PC) spark ignition timing (ST) effects were also explored, with the optimal timing at −8 °CA ATDC. ST has minimal impact on heat release rate (HRR), because high-energy jets could ensure rapid and stable combustion. Moreover, the combustion stability of TJI-HPDI was demonstrated, underscoring the importance in understanding and optimizing TJI-HPDI ignition processes.

Accumulation and Erase of Radiation-Induced Charge in MOS Structures

It is shown that when a MOS (metal–oxide–semiconductor) structure is simultaneously exposed to radiation and high-field injection of electrons, part of the radiation-induced positive charge can be erased when interacting with injected electrons, and the density of surface states can increase. These phenomena must be taken into account when operating MOS radiation sensors in high-field charge injection modes. High-field injection modes used for post-radiation erase of positive charge in MOS sensors are analyzed. It has been established that to annihilate one hole (radiation-induced positive charge), it is necessary to inject (0.5–2) × 104 electrons into the gate dielectric; the magnitude of the electric field has almost no effect on the process of erasing the radiation-induced charge.

Numerical Analysis of Reservoir Features and Injection Modes on Carbon Exchange Capacity during CO2-ECBM Processes

Numerical Analysis of Reservoir Features and Injection Modes on Carbon Exchange Capacity during CO₂-ECBM Processes

Heating characteristic of electron Bernstein wave using high-field side X-mode injection in QUEST

Abstract A comparative investigation was conducted to assess the impact of high-field side (HFS) extraordinary (X) mode (HFS X) injection and low-field side (LFS) ordinary (O) mode (LFS O) injection of 8.2 GHz radio frequency (RF) power in the Q-shu University experimental steady-state spherical tokamak. In the case of the HFS X injection, the ratio of electron plasma frequency and RF frequency f pe / f RF was 1.3, indicating an overdense plasma, whereas in the LFS O injection, this ratio was 0.9. Distinctive features emerged in the electron temperature and density profiles between the two injection scenarios. In the HFS X injection, the profiles peaked between the fundamental electron cyclotron resonance (ECR) layer and the upper hybrid resonance layer. Conversely, in the LFS O injection, the peaks were situated near the 1st ECR layer. This implies effective excitation of the electron Bernstein wave (EBW) in the case of the HFS X injection, with the wave power being absorbed through the doppler-shifted ECR of the EBW. Density and temperature oscillations were observed only in the start-up phase of the HFS X injection, which may correlate with the presence of the left-hand cutoff of the X-mode. These findings will be contributed to understand the distinctive characteristics associated with plasma heating through EBW excitation in the HFS X injection.

A-316 A quantitative gas chromatography tandem mass spectrometry method for metabolic profiling of urine organic acids and acylglycines

Abstract Background The analysis of urine organic acids (UOA) and acylglycines (UAG) are an essential investigation for the diagnosis inborn errors of metabolism (IEMs). The vast majority of methods for these analytes use gas chromatography mass spectrometry (GC-MS) and are only qualitative. Gas chromatography tandem mass spectrometry (GC-MS/MS) offers greater sensitivity and selectivity and enables the combination of qualitative screening with quantitative analysis. We describe the development and validation results of a quantitative GC-MS/MS method. Methods Urine creatinine concentrations were measured (CobasPro, Roche Diagnostics) and normalized to 1.25 mmol/L. After internal standard addition, each urine specimen, calibration standard and QC were incubated with a hydroxylamine solution followed by a liquid-liquid extraction. Further sample concentration permitted the isolated UOA and UAG to be derivatized using N,O-bis(trimethylsilyl)trifluoroacetamine (BSTFA) with 1% chlorotrimethylsilane (TMCS) prior to injection. GC-MS/MS analysis was performed using a GC-MS-TQ8050 triple quadrupole system (Shimadzu) with a 30 m DB-5MS (Agilent J&W) capillary column (0.25 mm, ID of 0.25 µm). Split injection mode was deployed with an initial column temperature of 70°C. The mass spectrometer was operated in electron ionization (EI) and multiple reaction monitoring (MRM) modes. Results The optimal temperature gradient for high-resolution UOA and UAG separations was derived and their respective retention times determined. MS/MS detection parameters were optimized to permit the identification of precursor and production ions for all (N=36) derivatized analytes. Total analysis time was 33.8 min per injection. This method permits the measurement of 11 samples in one batch and is highly linear for all analytes (R^2 >0.99 and average slope 1.04). The limit of quantification (LOQ) was established and ranged from <0.05 to 2.1 µmol/mmol creatinine. Intra- and inter-day imprecision (CV%) was determined using matrix-matched abnormal and normal QC. Intra-day imprecision (N=10) ranged from 1.3% (2-ketoglutaric acid) to 9.7% (3-hydroxybutyric acid). Inter-day imprecision (N=30 over 15 days) ranged from 2.2% (ethylmalonic acid and methylmalonic acid) to 20.5% (3-hydroxy-3-methylglutaric acid). The method had an average accuracy of 113±14% for analytes included in the ERNDiM quantitative organic acids (urine) external quality assurance program. For analytes not included in this proficiency testing, the method showed good agreement when compared to a national reference laboratory, with average Deming correlation coefficients and regression slopes being 0.9944 and 1.1, respectively. No interferences were detected when monitoring the analyte quantifier and qualifier ion ratios in patient urine. Conclusions The devised GC-MS/MS protocol permits the unbiased identification and quantification of UOA and UAG used to investigate IEMs. The method has acceptable sensitivity, specificity, precision and accuracy for clinical routine clinical testing.

Influence of elastic modulus on enhanced oil recovery ability of branched-preformed particle gel in porous media

A heterogeneous phase combined flooding system composed of polymers, surfactants, and branched-preformed particle gel (B-PPG) has been successfully applied to enhance oil recovery in mature reservoirs. However, the influence of elastic modulus on the enhanced oil recovery of B-PPG is unclear. Thus, based on the sand-pack flooding experiments and visual flooding experiments, the enhanced oil recovery ability of B-PPG with different elastic modulus and similar particle size was investigated under different injection modes. Results show that under the single-slug injection mode, the higher the elastic modulus, the higher the incremental oil recovery, and the better the ability to enhance oil recovery. With the increase in the elastic modulus from 0.7 Pa to 42.2 Pa, the incremental oil recovery increased from 12.7% to 32.6%. Under the multi-slug alternating injection mode, the incremental oil recovery of injecting low elastic modulus B-PPG slug followed by high elastic modulus B-PPG slug was 2.8% higher than that of injecting high elastic modulus B-PPG slug followed by low elastic modulus B-PPG slug. The incremental oil recovery of B-PPG under the multi-slug alternating injection mode was higher than that under the single-slug injection mode. At the microscopic level, the type of remaining oil was mainly clustered after water flooding. With the increase in the elastic modulus, the ratio of the clustered remaining oil decreased and the ratio of the multi-porous, columnar, and droplet remaining oil increased. Compared with the single-slug injection mode, it was easier to recover the clustered remaining oil by B-PPG flooding under the multi-slug alternating injection mode.

A new consecutive high-performance counter-current chromatography approach based on co-current and overlap mode for isolating active compounds from olive leaves

Conventional consecutive separation methods based on overlapping injection modes produce interactions between samples as the separation time increases. This will lead to a reduction in the purity of the target due to the gradual saturation of the stationary phase distribution. To enhance the purity of the sample preparation and separation efficiency, we devised a consecutive separation method under high-performance counter-current chromatography (HPCCC) utilizing co-current elution and overlapping injection. The method was used for the separation and preparation of olive leaves for their main bioactive polyphenolic constituents. Six HPCCC separations were conducted in reversed-phase mode using a two-phase solvent system consisting of petroleum ether/ethyl acetate/water (1:40:40, v/v). Finally, 302.7 mg of luteolin-4’-O-β-D-glucoside and oleuropein were isolated from 720 mg of crude sample with purities of 93.3 % and 96.2 %, respectively. The optimization strategy outlined in this study can be used to enhance the extraction of bioactive components from olive leaves.

Experimental Evaluation of Energy Enhancement and Fracturing Fluid Flowback Effect for CO2 Pre-Fracturing in Shale Reservoirs

Abstract Liquid CO2 pre-fracturing is a promising reservoir stimulation technology due to its advantages of increasing reservoir energy, low reservoir damage, and high fracturing fluid flowback rate. The on-site flowback scheme currently relies mainly on experience and requires further optimization of the energy enhancement effect and the flowback system. This paper presented a study on the changing law of liquid CO2 pre-fracturing energy-enhancing effect and fracturing fluid flowback rate in shale reservoirs was carried out by applying the experiments of drive-off and pressure-reducing flowback. The results indicate that, the injection of CO2 followed by linear gel fracturing fluid increased the energy (pressure) of the core system by approximately 322.8% compared to the injection mode of CO2 fracturing alone, and increased the energy (pressure) of the core system by approximately 24.1% compared to the injection mode of linear gel fracturing fluid. The energizing effect of the core system showed a trend of increasing and then decreasing with the increase of CO2 injection, and the best effect was achieved when the injection ratio of linear gel fracturing fluid to CO2 was 1:1. The flowback rate of the fracturing fluid and oil recovery both increased as the flowback differential pressure increased. Extending the soak time can increase the oil recovery, but the increase gradually decreases with the extension of the soak time. Additionally, the increase in soak time can improve the flowback rate of the core with relatively high permeability, but it has little effect on the flowback rate of the core with very low permeability.

Combination of high cetane diesel fuel and post injection mode in a diesel engine: A path towards lower exhaust emissions

The major objective of the presented work is to explore the effect of post injection (PI) strategy using neat diesel fuel (D100) blended with cetane number enhancer (CNE). The motive behind adding CNE in diesel fuel was to lower its self-ignition temperature and hence delay period subsequently. This can lead to more efficient combustion of post injected fuel which leads to lower incomplete combustion losses. The CNE used was Di-Tert-Butyl Peroxide (DTBP) which was blended with D100 in proportion of 1 % by volume. Initially experiments were conducted with D100 under various PI modes where variation of post injection timing (PIT) as well as post quantity (PQ) was considered. The experimental results showed that implementing PI resulted in lower smoke, unburned hydrocarbon (UHC), carbon monoxide (CO) and nitrogen oxides (NOx) emissions compared to single injection while affecting fuel consumption negatively. Then after similar experiments under various PI modes were repeated using blends of D100 and DTBP (D/DTBP) and results were compared with D100 case. It was found that addition of CNE in D100 resulted in more complete combustion of post fuel which further reduced CO and UHC emissions. The shorter delay period in case of D/DTBP blend compared to D100 case led to lower NOx emissions as well as higher smoke emissions. The obtained results revealed that PI mode with 3 mg PQ and 20° after top dead center (ATDC) PIT with D/DTBP blend offered 41.18 %, 17.55 %, 64 % and 62.5 % reduction in smoke, NOx, UHC and CO emissions respectively compared to single injection mode using D100 fuel.

EVALUATION OF EFFICIENCY OF OIL DISPLACEMENT BY WATER AND GAS AT VARIOUS MODES

The purpose of the work is to analyze in detail the efficiency of oil displacement by various agents, such as water and gas, at different modes. During the study, various methods and technologies aimed at increasing oil recovery were considered, and the effect of various parameters on the efficiency of the process was studied.Particular attention was paid to the method of water-gas impact (HBV) using pump-ejector systems (PES), which provides a triple impact on oil formations by simultaneous or alternate injection of water and gas.Theoretical and experimental methods were used to conduct the study. The beginning of the work was the study and analysis of scientific sources on the issue of assessing the effectiveness of oil displacement. Further, laboratory tests were carried out to assess the effectiveness of oil displacement by various agents. Experimental studies were carried out on a two-phase and three-phase filtration unit. The main parameter measured was the coefficient of oil displacement by water and separation gas. The effectiveness of the impact of various modes of water and gas exposure was studied: alternating (cyclic) injection of water and gas with different cyclicity, simultaneous injection of water and gas, as well as injection of a fine water and gas mixture.Based on the results of the work, it was concluded that the degree of influence of wetting processes on the final displacement result is a critical factor. The following main points can be distinguished:- final value of oil displacement coefficient depends on selection of displacement agent;- in case of water and gas impact, the sequence of water and gas injection is of great importance;- the efficiency of oil displacement is highly dependent on the absolute permeability of the reservoir, as well as on the injection mode (sequential, simultaneous, cyclic).The results of the experiments can be useful for predicting the development of oil fields and choosing optimal methods for increasing oil recovery.The uniqueness of this article lies in the study of the possibilities of using multithreaded ejectors to increase the efficiency of hydrocarbon production.

Comparative experimental study on the co-firing characteristics of water electrolysis gas (HHO) and lean coal/lignite with different injection modes in a one-dimensional furnace

Zero-carbon fuels (H2/NH3) replacing coal co-firing is a promising way to address carbon emissions. Hydrogen co-firing helps improve combustion stability at low loads and control pollutant emissions. This study used a safer water electrolysis gas (HHO) for the multi-coal co-firing adaptability test. The effects of HHO injection mode and flow rate on combustion intensity, flue gas emissions, and fly ash characteristics were investigated. The results showed that HHO and lean coal/lignite co-firing could significantly increase the combustion temperature. The maximum temperature increases after co-firing were 108 °C and 95 °C. As the HHO increased, the CO2 in lignite co-firing increased, and CO and unburnt carbon decreased, while the opposite results were observed for lean coal (LC). At the 2200L/h HHO co-firing, CO2 decreases by 14.46 % and 27.22 % for LC premixed co-firing (PC) and staged co-firing (SC). Compared to SC, PC is more conducive to promoting the complete combustion of coke. The NOX emissions of HHO/LC co-firing are lower than those of pure coal, reaching the lowest value of ∼ 9 ppm under SC. As the HHO increases, the NOX of Lignite-PC first increases and then slowly decreases, while Lignite-SC has the opposite effect. Although various NOX emission trends are observed under different conditions, the results are dominated by a common mechanism − the competition between NOX reduction caused by HHO gas and the increase in co-firing temperature on NOX generation. The NOX of SC is all lower than that of PC. The SO2 emission from the LC co-firing decreases with the increase of HHO, while the SO2 from lignite increases. The SO2 of LC-SC can be reduced from ∼ 142 ppm to 0 ppm. HHO gas injection inhibits the release and oxidation of sulfur in lean coal. The differences in coal types lead to different changes in SO2 of co-firing. HHO gas reduced the SO3 content of lignite fly ash by 38.01 %. The high-temperature reduction atmosphere promotes the decomposition of sulfates and increases SO2 emissions. HHO co-firing refines the particle size of fly ash. The ultra-fine and micron particle matter (PM) increases, and the content of PM>100μm in Lignite-SC decreased by 10.32 %.

The Influence of Injection Mode and Spray Distance on Wear Resistance of Al2O3+13 wt.% TiO2 coatings

Abstract Atmospheric plasma spraying (APS) allows deposition of ceramic coatings on metallic substrate, significantly increasing the wear resistance of the component. Coating’s microstructure and consequently its properties, depend on heat treatment of the feedstock particles. This property can be controlled by process parameters, especially electric power and spray distance. On the other hand, some plasma torches allow introducing another variable, an injection mode, which could be realized in external or in internal way. In the presented research, wear resistance of Al2O3+13 wt.% TiO2 coatings deposited under various values of spray distance and different injection modes were examined using ASTM G-99 procedure. The impact of spraying parameters on the coating’s microstructure was established and connected to the functional properties of the manufactured deposits. Observed differences indicated influence of injection mode and spray distance value. Coatings deposited with internal feedstock injection exhibit lower porosity and slightly higher hardness than these made with external injection mode. In terms of wear resistance for both spray distance the wear factor was lower for internal injection system. Obtained results confirmed assumed thesis, that internal injection mode improves heat treatment and consequently ameliorate wear performance of plasma sprayed alumina-titania coatings.

Numerical simulation of the dynamic interaction characteristics between Wood’s metal and water under coolant injection mode

The accident of the steam generator tube rupture in the lead-bismuth-cooled fast reactor or the core meltdown in the light water reactor may cause violent heat and mass transfer between the melt and the coolant, potentially further damaging the reactor. Therefore, it is essential to study the corresponding mechanisms. In this study, numerical simulations are utilized to investigate the dynamic interactions between Wood’s metal and subcooled water in the coolant injection (CI) mode, focusing on jet behavior and critical cavity parameter changes. By analyzing these factors, this research aims to clarify the interfacial evolution and interaction mechanisms between the melt, water, and air, thereby tackling the problem of inadequate observation in experiments. A user-defined function (UDF) was employed to simulate the flow characteristics of the melt during the solidification process. This approach effectively addressed the limitation of Fluent’s inherent solidification model, where the fluid no longer participates in turbulent velocity calculations after solidification. In addition, an equivalence method was proposed according to the characteristics of two-dimensional simulations in Fluent. Comparisons with Cheng’s experimental results show that the equivalent model can accurately predict jet penetration characteristics while significantly reducing the demand for computational resources. According to this equivalence method, this research developed a new correlation for predicting the maximum jet penetration depth in the CI mode. The above results provide new perspectives for understanding the dynamic interactions between metals and coolants, which is significant for the application and optimization of technologies in the nuclear field.

Comparative study on combustion and emission of ternary-fuel combined supply SI engine with oxyhydrogen/ethanol/gasoline by different injection modes of fuel

The combination of renewable energy and multifuel combined supply is an efficient way to deal with the energetic crisis and the pollution of environment. Ethanol, gasoline and oxyhydrogen participate in combustion by means of three independent supply paths, which can improve engine power and reduce gasoline consumption and gaseous pollutant emission at the same time. However, the optimization of ternary-fuel combined supply mode is a problem that must be clarified. In this study, the engine performance at four direct injection pressure (DIP), six direct injection timing (DIT), five intake manifold absolute pressures (MAP) and four speeds is studied under the condition of equal ethanol injection ratio and gasoline injection ratio. The experimental results show that ethanol direct injection forms a mixture with a better stratified combustion state than gasoline direct injection. Moreover, oxyhydrogen negatory pressure inhalation (ONPI) can effectually increase Pmax and IMEP, reduce APmax, CA 10–90, CA 0–10, CO emission, HC emission and particulate emission, but increase NOx emission. However, ethanol direct injection (EDI) can reduce NOx emission produced by ONPI, and oxyhydrogen can attenuate the negatory effect on mixture combustion due to the excessive latent heat of vaporization of ethanol. NO emission in EDI mode is reduced by an average of 28.39 % compared to gasoline direct injection (GDI) mode under different MAPs. In conclusion, the combustion and emission characteristics of the engine in EDI + gasoline port injection (GPI) + ONPI mode are better than those in ethanol port injection (EPI) + GDI + ONPI mode. And the control strategy of "9–11 MPa DIP+250–300°CA BTDC DIT +16 L/min oxyhydrogen negative pressure inhalation volume (ONPIv)" can improve the performance of EDI + GPI + ONPI engine while reducing emission.