Fluid Nozzle Research Articles

Energy-economic-environmental analysis of bifacial photovoltaic thermal (BPVT) solar air collector with jet impingement

Jet impingement cooling enhances photovoltaic (PV) system efficiency by using high-speed fluid jets to reduce panel temperatures, improving performance and longevity. The effectiveness depends on factors like fluid flow rate, nozzle placement, and distance from the panel. While it boosts energy output, it may increase energy use for fluid circulation and add complexity to the system. This research explores a groundbreaking approach to enhancing the efficiency of bifacial photovoltaic thermal (BPVT) systems by integrating jet impingement technology. A novel design featuring a jet plate reflector is introduced, offering the dual benefit of cooling the PV panels while simultaneously reflecting light to optimize energy capture. The study comprehensively analyses the system’s performance, including energy output and a detailed techno-economic and environmental-economic evaluation. The modelling in this study was validated and reasonably consistent with experimental results. The system's output air temperature and thermal efficiency are 302.07–318.75 K and 33.83–62.28 %, respectively. The temperature and electrical efficiency range for PV systems are 304.39–339.54 K and 9.39–11.22 %. Reduced mass flow rate and increased solar irradiation are the most economically advantageous operating parameters for the proposed system, resulting in lower annual pumping costs and more significant annual energy gains for the system. CBR variations range from 0.1363 to 9.3445, with an average of 2. Additionally, by using BPVT with jet impingement to generate electricity rather than fossil fuels, it is possible to reduce annual carbon dioxide emissions by approximately 1.61 tons and save RM93.51 annually. In general, the proposed method should be used to minimize environmental pollution.

Performance assessment of graphene oxide based nano-cutting fluids during sustainable hard turning through synthesis, characterization and machinability investigation

Achieving sustainability in manufacturing necessitates the implementation of eco-friendly solutions by adopting environmentally friendly coolants with cost-effective, energy-efficient and cleaner production processes without posing any risk to the operator's health. In this current work, mineral oil-based graphene oxide (GO) nano-cutting fluids of different concentration (0.05, 0.1, 0.2, 0.3, 0.4, 0.5 % wt.) are synthesized and their characteristics such as rheological, thermo-physical and tribological properties along with their stability and toxicology impact are thoroughly investigated. Further, the influence of nano-cutting fluid concentration on machinability and sustainability aspects during hard turning such as flank wear, surface integrity, power consumption, cutting temperature, carbon and noise emissions are investigated. According to the result an enhancement of 28.83 % and 29.54 % in viscosity and thermal conductivity have been recorded when concentration of nanofluid increases from 0.05 % to 0.5 %. GO nano-cutting fluids shows anti wear and friction reduction properties by providing excellent lubricious properties, as a result coefficient of friction has been reduced up to 28.36 % at 0.5 % wt. GO compared to plane mineral oil. A notable reduction in flank wear, cutting temperature, surface roughness, cutting temperature, power consumption, carbon emission and noise emission were noticed to be 25.96 %, 27.82 %, 23.86 %, 25.22 %, 11.66 % and 2.72 % respectively when the concentration of GO nanoparticles increases from 0.05 % to 0.5 % wt. Smoother surface with minimal defect has been noticed from the SEM and AFM image of machined workpiece at highest concentration (0.5 % wt.) of GO due to the synergetic effect of GO nano-cutting fluid and dual nozzle MQL system.

Characterization and in vitro bioaccessability of optimized chia oil-Capsul-sodium alginate microparticles obtained by 3 nozzle spray-drying

The influence sodium alginate (SA) as an outer layer agent on bioaccessibility and matrix food release of purified chia oil (PCO) microencapsulated was investigated. PCO microparticles with Capsul were elaborated and optimized by response surface methodology (RSM), and then as an encapsulating agent and SA as an outer layer (PCO-Capsul/SA) were designed by mini spray-drying with 2 fluid nozzle (2-N) and 3 fluid nozzle (3-N). The optimal conditions obtained for PCO-Capsul system were: dryer inlet temperature of 114 °C and PCO:Capsul relation of 1:5.42. After the addition of SA out layer, PCO-Capsul/SA microparticles were subjected to in vitro static gastrointestinal digestion. PCO-Capsul/SA occurred mainly in the intestinal phase, showing the suitability of SA as an intestine-site release polymer. However, when PCO-Capsul/SA was incorporated into a yoghurt (Y), microparticles showed a significantly lower PCO matrix food release and bioaccessibility after in vitro digestion than PCO-Capsul-Y microparticles, due to their interaction between SA and Y. SA spray-dried by 3-N showed great potential for vehiculation of omega-3 rich oils in the future incorporation and develop of functional foods. Tweetable abstractThis research shows the role of the sodium alginate incorporation by 3 nozzle spray dryer when the design of an intestine-delivery food ingredient is intended.

Stagnation point heat transfer under a free-surface jet

Laminar free-surface jet impingement is a crucial configuration for heat transfer processes. Focusing on the link between stagnation-point heat transfer and near-axis radial acceleration, its dependence on jet width and profile is studied. Thus, heat transfer depends on: fluid properties, flow rate, nozzle length, nozzle-to-plate spacing, surface tension and gravity (Pr, Re, L/d, H/d, We & Fr, accordingly). As existing theory is limited to specific cases, a new general description is developed from analogy to submerged jets. Validated by two-phase flow simulations, this description captures key jet dynamics evolution (centerline velocity, profile curvature). It reveals significant property changes during jet flight due to relaxation (L dependence) and contraction (Re/Fr dependence). Unlike submerged jets, contraction raises arrival Reynolds number, leading to additional dependencies Nu ∝ L and Nu ∝ H/Fr, and further deviations at low-We and -Re. The theory successfully predicts heat transfer across diverse conditions and converges to negligible gravity (horizontal jet) as expected.

Novel methods to induce complex coacervation using dual fluid nozzle and metal membranes: Part II – Use of metal membrane technology to induce complex coacervation

In this follow up study, which is the extension of our previous work on the use of metal membranes for production of ginger oil emulsions with engineered droplet size (part I), we continue the exploration of membrane technology for production of complex coacervates. In this paper (part II) we introduced a novel method to induce multi core complex coacervation using metal membrane technology - which has been most used for drop-by-drop emulsification. Gelatin (4% and 10% w/w) and ginger oil (gelatin to ginger oil ratio 1:1) emulsions were produced using the high shear homogenization followed by injection through the metal membranes to induce complex coacervation using gum Arabic at pH 3.5 using a dispersion cell. The capsules (coacervates) produced using metal membrane (with 24 µm pore diameter) had spherical shape with diameters between 53 and 72 µm. Encapsulation efficiency ranged between 61% and 93% while the encapsulation yield varied from 15% to 90%, being significantly higher for emulsions with 4% (w/w) of gelatin. Complex coacervation by metal membrane was compared with coacervation induced by atomization and batch stirring. The methods discussed in this study can be potentially used in encapsulation of both lipophilic and hydrophilic compounds. Finally considering encapsulation properties and the possibility of engineering the capsules size, the use of membrane technology is a promising new configuration to induce complex coacervation, with real possibilities to allow scale up of the process of complex coacervation.

Development of excipients free inhalable co-spray-dried tobramycin and diclofenac formulations for cystic fibrosis using two and three fluid nozzles

This study aims to investigate the effect of physicochemical properties and aerosol performance of two (2FN) and three-fluid nozzles (3FN) on the inhalable co-formulation of tobramycin and diclofenac dry powders. Combination formulations of tobramycin and diclofenac at 2:1 and 4:1 w/w ratios were prepared at a laboratory scale using a spray dryer in conjunction with a 2FN or 3FN. Powder size, morphology, solid-state characteristics, and aerodynamic and dissolution properties were characterised. The nozzle types and the formulation composition influenced the yield, particle size, solid-state properties, aerosolization behaviour and dissolution of the co-spray dried formulations. In particular, using the 2FN the co-spray dried formulation of tobramycin and diclofenac at 2:1 w/w showed smaller particle size (D50, 3.01 ± 0.06 μm), high fine particle fractions (FPF) (61.1 ± 3.6% for tobramycin and 65.92 ± 3 for diclofenac) and faster dissolution with approx. 70% diclofenac released within 3 h and approx. 90% tobramycin was released within 45 min. However, the 3FN for the co-spray dried formulation of tobramycin and diclofenac at a 2:1 w/w ratio showed a larger particle size (D50, 3.42 ± 0.02 μm), lower FPF (40.6 ± 3.4% for tobramycin and 36.9 ± 0.84 for diclofenac) and comparative slower dissolution with approx. 60% diclofenac was released within 3 h and 80% tobramycin was released within 45 min. A similar trend was observed when the tobramycin to diclofenac ratio was increased to 4:1 w/w. Overall results suggest that spray drying with 2FN showed a superior and viable approach to producing excipients-free inhalable co-spray dried formulations of tobramycin and diclofenac. However, the formulation produced using the 3FN showed higher enrichment of hydrophobic diclofenac and an ability to control the tobramycin drug release in vitro.

Novel methods to induce complex coacervation using dual fluid nozzle and metal membranes: Part I – Use of metal membranes for emulsification

This study is part I of two parts where the use of metal membranes was evaluated to produce emulsions and to induce complex coacervation. In this work, we aimed to produce emulsion droplets using metal membranes to be used in complex coacervation in batch stirring and by a new method in which coacervation is induced using a two-fluid nozzle. Investigation on the optimum membrane morphology, dispersed phase injection rate and emulsification shear stress was carried out. Emulsions of gelatin and ginger oil (4% and 10% w/w) were produced by membrane emulsification in a dispersion cell, with droplet sizes varying from 32 to 128 µm; gelatin concentration had great influence on droplet size and size distribution. Complex coacervation between gelatin and gum Arabic without the use of crosslinking agents was carried out by atomization and batch stirring, and the size of the parent emulsion droplets, coacervation shear stress and emulsion formulation influenced the size of the capsules produced, which varied from 35 to 151 µm. Batch stirring complex coacervation produced single core capsules and atomization coacervation produced multicore capsules, both with spherical morphology. Encapsulation yield of dried capsules varied from 37% to 99% and encapsulation efficiency 5–66%. Formulation had a greater effect on the encapsulation efficiency than on the encapsulation yield.

A novel direct ink writing manufacturing system to 3D print highly concentrated silk fibroin

Silk fibroin has demonstrated high biocompatibility in contact with the human tissue and in cell culture. As a result, it has been studied to develop very promising medical devices. The medical field has initiated a trend towards customization that will prevail in the recent future. That is why, 3D printed medical devices are gaining attention and becoming more relevant. This work attempts to unify silk fibroin with 3D printing. For this purpose, a high-concentration silk fibroin extrusion system has been designed. This system consists of a novel method to concentrate the fibroin to an optimal viscosity for direct ink writing. This could be accomplished due to the shear shinning property of the silk, after being expelled the viscosity keeps the shape of the silk in the place where it was deposited. Then, the system applies temperature to the silk to create a solid structure. A modular prototype has been created. It can print on any type of surface, flat or tubular. To evaluate the accuracy of the system on a flat printing bed, fluid flow rate and nozzle speed were evaluated in the fabrication of a mesh that simulated a flat cardiovascular stent. Images of the results were captured with a stereoscopic microscope, the dimensions of the result were calculated and compared with the chosen parameters. Thus, this work characterizes these features with the print resolution of the system. Finally, it opens a new paradigm for 3D printed medical devices based on silk fibroin.

Effect of Storage Humidity on Physical Stability of Spray-Dried Naproxen Amorphous Solid Dispersions with Polyvinylpyrrolidone: Two Fluid Nozzle vs. Three Fluid Nozzle.

In a spray drying operation, a two-fluid nozzle (2FN) with a single channel is commonly used for atomizing the feed solution. However, the less commonly used three-fluid nozzle (3FN) has two separate channels, which allow spray drying of materials in two incompatible solution systems. Although amorphous solid dispersions (ASDs) prepared using a 3FN have been reported to deliver comparable drug dissolution performance relative to those prepared using a 2FN, few studies have systematically examined the effect of 3FN on the physical stability. Therefore, the goal of this work is to systematically study the physical stability of ASDs that are spray-dried using a 3FN compared to those prepared using the traditional 2FN. For the 2FN, a single solution of naproxen and polyvinylpyrrolidone (PVP) was prepared in a mixture of acetone and water at a 1:1 volume ratio because 2FN allows for only one solution inlet. For the 3FN, naproxen and PVP were dissolved individually in acetone and water, respectively, because 3FN allows simultaneous entry of two solutions. Upon storage of the formulated ASDs at different humidity levels (25%, 55% and 75% RH), naproxen crystallized more quickly from the 3FN ASDs as compared with the 2FN ASDs. 3FN ASDs crystallized after 5 days of storage at all conditions, whereas 2FN ASDs did not crystallize even at 55% RH for two months. This relatively higher crystallization tendency of 3FN ASDs was attributed to the inhomogeneity of drug and polymers as identified by the solid-state Nuclear Magnetic Resonance findings, specifically due to poor mixing of water- and acetone-based solutions at the 3FN nozzle. When only acetone was used as a solvent to prepare drug-polymer solutions for 3FN, the formulated ASD was found to be stable for >3 months of storage (at 75% RH), which suggests that instability of the 3FN ASD was due to the insufficient mixing of water and acetone solutions. This study provides insights into the effects of solvent and nozzle choices on the physical stability of spray-dried ASDs.

Three fluid nozzle spray drying for co-encapsulation and controlled release of curcumin and resveratrol

This study reports the first time development of sodium alginate and carboxy methyl cellulose microparticles for co-delivery of curcumin and resveratrol through conventional two fluid nozzle (2FN) and three fluid nozzle (3FN) spray drying. More than 9% increase in loading capacity and encapsulation efficiency of bioactives was observed in microparticles formed through 3FN than from 2FN spray drying. Florescence imaging proved the formation of core-shell microparticles from 3FN spray drying. DSC and XRD pattern confirmed that encapsulation changes the crystallinity of bioactives to amorphous form. Controlled release of resveratrol encapsulated in the core of the microparticles produced from 3FN was evident in comparison with 2FN microparticles. Release kinetics of both bioactives best fit the Korsmeyer-Peppas model, explaining pseudo-Fickian diffusion mechanism for resveratrol from core and anomalous diffusion for curcumin from shell. Overall, results confirmed that the 3FN spray drying is a prospective commercially scalable approach for effective co-delivery of bioactive molecules.

Cross-linked chitosan microparticles preparation by modified three fluid nozzle spray drying approach

Owing to chitosan’s incredible biocompatibility and biodegradability, bioactive molecules loaded delivery systems based on this polymer have been widely studied for improved health benefits. In the present work, quercetin and ferulic acid encapsulated core-shell structure chitosan microparticles crosslinked with tripolyphosphate and sodium alginate have been fabricated using unique three fluid nozzle (3-FN) spray drying technique. Fluorescent molecules incorporated into the microparticles aided observation of core-shell structure formation. Compatibility studies, physicochemical properties, and free radical scavenging activity of microparticles were assessed. Microscopic analysis revealed core-shell structured, spherical shaped microparticles. Thermal and non-thermal method of evaluation confirmed the crosslinking, compatibility and encapsulation of bioactive molecules with the carrier materials. The dual bioactive molecules-loaded microparticles exhibited sustained release pattern (85–88%) for 24 h and had better free radical scavenging potency. Such cross-linked core-shell structured microparticle is a promising dual delivery system for encapsulating bioactive molecules with synergistic antioxidant activity.

Analysis of turbulence in convergent-divergent nozzles with fluid insert noise reduction technology

The noise generated by tactical fighter aircraft engines is harmful to personnel working in the vicinity of the aircraft and can cause annoyance to communities in the vicinity of air bases. The primary noise sources in supersonic jets are related to the supersonic convection of large-scale turbulent structures, which generate intense noise in the jet downstream direction, and the interaction of the turbulence with the jet’s shock cell structure that results in broadband shock-associated noise, which radiates predominantly in the sideline and upstream directions. The use of fluid inserts in the divergent section of variable area exhaust nozzles has been shown experimentally, at small and moderate scale, to reduce noise radiation from both noise sources. To understand the fluid insert noise reduction mechanisms, a Large Eddy Simulation database is developed and analyzed. The focus is on differences between turbulence properties in a baseline and a fluid insert nozzle. The flow database is analyzed using Spectral Proper Orthogonal Decomposition and Doak’s Momentum Potential Theory. The latter theory permits the decomposition of the flow into hydrodynamic, thermal and acoustic components. The changes in the acoustic component are related to the observed changes in the radiated noise.

Numerical Study on Injection Characteristics of Bio-oil using Twin Fluid Nozzle for Bio-oil Gasification Reactor

Numerical Study on Injection Characteristics of Bio-oil using Twin Fluid Nozzle for Bio-oil Gasification Reactor

일유체 노즐을 이용한 실내 수분무가습 방식 클린룸의 에너지소비량에 관한 실험적 연구

일유체 노즐을 이용한 실내 수분무가습 방식 클린룸의 에너지소비량에 관한 실험적 연구

EFECTO DE BOQUILLAS NEUMÁTICAS DE DOS FLUIDOS EN LAS CARACTERÍSTICAS DE ESTABILIDAD DE LAS EMULSIONES ELABORADAS CON MÉTODO DE ALTA ENERGÍA (MICROFLUIDIZACIÓN)

The atomization of oil in water emulsions is used in the food industry such as in the preparation of capsules, films and coatings among others. However, the passage through the atomization devices could have an influence on the properties of the emulsion and, consequently of the final product. In the present work, it was evaluated the influence of two fluid nozzles of different dimensions on stability parameters of oil in water emulsion produced by microfluidization and using gum Arabic as wall material. Results indicated that the droplet size, the polydispersity index and the Turbiscan stability index of atomized emulsions were affected by and Oswald ripening mechanism as compared with those of the original emulsion. The confocal laser scanning microscopy images confirmed that the passage of the emulsion through the atomization devices decreased the thickness of wall material of the droplets with respect to the original emulsion. It was concluded that, in the proper design of the final products prepared by atomization it must be considered its effect on the stability of the atomized emulsions by including during the processing, a suitable sampling-characterization on-line scheme.

Near-field dynamics of high-speed spray dryer coannular two fluid nozzle: Effects of operational conditions and formulations

The scaling-up of spray drying processes is an important and challenging step in commercializing specialty products with an ensured quality because it mandates a comprehensive understanding of several steps in the process such as atomization, efficient solvent removal, and particle segregation. The formation of needed particle sizes and shapes is impossible without appropriate atomization through spray dryer nozzles. Hence, research is discussed that investigates the atomization mechanism for a pilot scale externally-mixed, two-fluid nozzle spray dryer by using time resolved particle-image velocimetry to study the behavior of droplets in the near-field of the nozzle tip. Important near-field dynamics of droplets emanating from the nozzle are described, and particle formation characteristics are discussed for several formulations which are widely used in the pharmaceutical industry. Spray angle, droplet breakup length, and droplet sizes and velocity distributions are characterized. Understanding these parameters assists the interpretation of particle formation and enables the modeling of the spray drying process.

Experimental Study on Suppression Effect of Inert Gas Two Fluid Water Mist System on Methane Explosion

Abstract At present, there have been large numbers of methane transport pipelines in coal mine in china. Explosion accident is most likely to be triggered if affected by leakage or external fire. In order to improve the suppression effect of single fluid water spray technology, this paper studied the suppression performance of two fluid water mist system on methane/air explosion. A transparent organic glass pipeline was designed for gas explosion, with the dimensions of 0.84 × 0.12 × 0.12 m. A two fluid nozzle was used to suppress methane/air explosion. Then testing was performed on the explosion suppression properties of two fluid water mist system by adjusting the spray time and N2 and CO2 pressure. The explosion suppression effect of the inert gas two fluid water mist was examined by analyzing the methane explosion overpressure and flame propagation speed. The experimental results showed that: when using N2 or CO2 for the driving force, the explosion suppression effect of the inert gas two fluid water mist was significant, and the peak explosion overpressure, average rise rate of pressure rise and peak speed value of the explosion flame were all gradually decreased by extending the spray time. Such as when the spray time was 3 s and the CO2 pressure was 0.4 MPa, the average velocity of the flame decreased by 81.32%, peak explosion overpressure decreased by 51.44%, and average pressure rise rate decreased by 72%.

Grinding Fluid Jet Characteristics and Their Effect on a Gear Profile Grinding Process

Profile gear grinding is characterized by a high level of achievable process performance and workpiece quality. However, the wide contact length between the workpiece and the grinding wheel is disadvantageous for the fluid supply to the contact zone and leads to the risk of locally burning the workpiece surface. For the reduction of both the thermal load and the risk of thermo-mechanical damage, the usage of a grinding fluid needs to be investigated and optimized. For this purpose, different kinds of grinding fluid nozzles were tested, which provide different grinding fluid jet characteristics. Through a specific design of the nozzles, it is possible to control the fluid flow inside the nozzle. It was found that this internal fluid flow directly influences the breakup of the coolant fluid jet. There are three groups of jet breakup (“droplet”, “wave & droplet”, and “atomization”). The first experimental results show that the influence of the jet breakup on the process performance is significant. The “wave & droplet” jet breakup can achieve a high process performance, in contrast to the “atomization” jet breakup. It can therefore be assumed that the wetting of the grinding wheel by the grinding fluid jet is significantly influenced by the jet breakup.

Structural and oxidative stabilization of spray dried fish oil microencapsulates with gum arabic and sage polyphenols: Characterization and release kinetics.

The synergistic efficacy of gum arabic and sage polyphenols in stabilising capsule wall and protecting fish oil encapsulates from heat induced disruption and oxidative deterioration during spray drying was assessed. The emulsions prepared with sodium caseinate as wall polymer, gum arabic as wall co-polymer and sage extract as wall stabiliser was spray dried using a single fluid nozzle. Fish oil encapsulates stabilised with gum arabic and sage extract (SOE) exhibited significantly higher encapsulation efficiency compared to encapsulates containing gum arabic alone (FOE). Scanning electron microscopic and atomic force microscopic images revealed uniform encapsulates with good sphericity and smooth surface for SOE, compared to FOE powder. In vitro oil release of microencapsulates indicated negligible oil release in buffered saline whereas more than 80% of the oil loaded in encapsulates were released in simulated GI fluids. The encapsulates containing sage extract showed a lower rate of lipid oxidation during storage.

Simulation of the primary breakup of a high-viscosity liquid jet by a coaxial annular gas flow

The conversion of low-grade fossil and biogenic energy resources (petcoke, biomass) to a synthesis gas in a high pressure entrained flow gasification process opens a wide spectrum for high efficient energy conversion processes. The synthesis gas can be used for production of methane (SNG), liquid fuels (BtL, CtL) or as fuel for operation of a gas turbine in a combined cycle power plant (IGCC). The production of a tar free high quality syngas is a challenging objective especially due to the fact that typical liquid or suspension fuels for entrained flow gasifiers feature viscosities up to 1000 mPas. Fuel droplet conversion at typical entrained flow gasification conditions is characterized by heat up, evaporation and subsequent degradation of the vapour phase. To guarantee a high fuel conversion rate in the gasifier an efficient atomization of the fuel is required. Mainly twin-fluid burner nozzles are used for atomization of those typically high viscous fuels. The present study is focused on the assessment of the accuracy of CFD computations for the primary breakup of high-viscosity liquids using an external mixing twin fluid nozzle. In a first step experiments were performed with a Newtonian glycerol-water-mixture featuring a liquid viscosity of 400 mPas. Jet breakup was investigated using a high speed camera as well as PIV and LDA-System for a detailed investigation of the flow field. In a second step the experimental results serve as reference data to assess the accuracy of CFD computations. Compressible large eddy simulations (LES) were performed to capture the morphology of the primary breakup as well as the important flow field characteristics. A Volume of Fluid (VOF) approach was used to track the unsteady evolution and breakup of the liquid jet. Comparison of experimental and numerical results showed good agreement with respect to breakup frequency, velocity fields and morphology.