Double Nozzle Research Articles

A four-channel air pressure cooperative control system for 3-D bio-printing device

In recent years, the research and development of 3D bioprinting device for artificial blood vessels has attracted great attention of researchers. In this paper, the research object is the control system of 3D bioprinting device for artificial blood vessel and the four-channel air pressure cooperative control technology for 3D bioprinting device double nozzles printing is mainly studied. Through the scheme design, working principle innovation, hardware selection and air pressure output calibration experiment of four-way air pressure cooperative control system, the hardware platform of 3D bioprinting device air pressure control system is built. Then, by using the embedded TwinCAT NC PTP software platform based on EtherCAT Ethernet bus protocol, the four-channel air pressure cooperative control is programmed and field experiments are carried out, which realizes the printing process of uniform liquid output and good continuity, and meets the requirements of 3D bioprinting for printing continuity and forming quality. The study of four-channel air pressure cooperative control system in this course is a worthy of application and promotion control method.

Pengaruh jumlah nozzle terhadap kinerja turbin pelton sebagai pembangkit listrik di Desa Sumber Agung Kecamatan Suoh Kabupaten Lampung Barat

A micro hydro power plant, or commonly known as a turbine is a power plant that utilizes the potential energy of water to be converted into mechanical energy which is then converted into electrical energy using a generator. The Pelton turbine is an extension of the impulse turbine with a split some blades dividing the jet into two equal beaks which are reversed sideways at the turbine wheel. This study aims to determine the effect of the number of nozzles to output power, efficiency, and electric power produced. In this study, a Pelton type water turbine was applied to a water source flowing from the mountains with a head of 26 m and 0.003167 m3/s water discharge. This study used 3 variations of the number of nozzles (single, double, and triple nozzle) with 9 mm outer diameter of nozzle and 35 mm nozzle length. The results of the research conducted, the turbine power is 419.53 watts, the turbine efficiency is 52%, and the generator power is 360 Watts for triple nozzle variation. The turbine power obtained is 388.83 Watts, the turbine efficiency is 48%, and the generator power is 234 Watts for double nozzle variation. And the power obtained is 367.47 Watts, the turbine efficiency is 45%, and the generator power is 175 Watts for single nozzle variations.

The Influence of the Spraying Pressure of an Injector Asymmetric Double Nozzle with Variable Flow on Head Fungicide Coverage, Yield, Grain Quality, and Deoxynivalenol Content in Winter Wheat

Spraying parameters are important factors when spraying wheat heads against fusarium head blight (FHB) to control the deoxynivalenol level in the grain and to obtain high and quality yields. In 2019 and 2020, field trials were conducted in order to establish the effect of the spraying pressure (2 bar, 4 bar, and 6 bar) of special nozzles with a variable flow rate Agrotop VR 1.5 on the head fungicide coverage, yield parameters, and the deoxynivalenol (DON) value in the grain. The coverage of the front and rear sides of wheat heads increased with the increase of spraying pressure from 2 to 6 bar. In 2019, when the infection with FHB was more severe, no significant differences appeared in the yield and the hectoliter weight at a lower spraying pressure, while the DON value at this pressure approached the maximum permissible level. In that year, the DON value exponentially fell with the increase of spraying pressure. In 2019, the thousand grain weight was higher at the spraying pressure of 6 bar than at the pressures of 2 and 4 bar. The results show that also a lower spraying pressure (2 bar) and a volume application rate (117 L/ha) below the recommended one suffice to retain the DON value in the grain below the maximum permissible level, even in years with more severe infection.

Tailoring Cu substituted hydroxyapatite/functionalized multiwalled carbon nanotube composite coating on 316L SS implant for enhanced corrosion resistance, antibacterial and bioactive properties.

The aim of the present work is to study the potential change in the antibacterial properties of Cu-hydroxyapatite/functionalized multiwall carbon nanotube (HA/f-MWCNT) composite coated heterogeneous implant surfaces against Gram positive and Gram-negative microorganism and to reveal the possible contribution of surface corrosion effects arising in stimulated body fluid. Novel spray pyrolysis instrument designed with double nozzle was used for the fabrication of Cu-hydroxyapatite/f-MWCNT film on 316L stainless steel (SS). The Cu-hydroxyapatite/MWCNT coated bioimplant was characterized by a series of techniques to identify the crystallinity, chemical bonds, surface morphology and elemental composition. The results disclose that the coated implants exhibit highly crystalline nature with the space group of P63mc and spherical shaped morphology. The corrosion current density revealed a remarkable decrease from 6.8 to 3.8 μA suggesting that the Cu substituted hydroxyapatite/f-MWCNT composite coating provided higher barrier properties which is beneficial to achieve higher corrosion protection of 316L SS implant. The hybrid Cu-hydroxyapatite-MWCNT composite revealed better antibacterial ability than HA/MWCNT for both gram positive and gram-negative bacteria with a maximum inhibition zone of 13-17mm, compared with hydroxyapatite/f-MWCNT. The antibacterial ability of the Cu-hydroxyapatite/f-MWCNT nanocomposites was effective against Escherichia coli compared with other microorganisms. The Cu-hydroxyapatite/f-MWCNT nanocomposite exhibited that the coated material is nontoxic, biocompatible and suitable for biomedical application.

Fine stripe coating and micro patterning of organic thin films using double nozzles for OLEDs

The aim of this work is to investigate the feasibility of coating and patterning of fine organic thin-film stripes using double nozzles. For fine stripe coating of an aqueous poly (3,4-ethylenedioxythiophene):poly (4-styrenesulfonate) (PEDOT:PSS), we have changed the outer surface of the needle from hydrophilic to hydrophobic in such a way that lateral capillary force is suppressed and thus the PEDOT:PSS stripe becomes narrow. Using a table coater with the hydrophobic needle (inner diameter = 51 μm), we have achieved the 54-μm-wide PEDOT:PSS stripe at a maximum coating speed of 30 mm/s. For micro patterning of PEDOT:PSS thin-film stripes, we have employed double needles; one for discharging the main solvent of the underlying thin film and the other for sucking the dissolved thin film. It is found that the pattern width decreases as the patterning speed increases and the pattern factor (the ratio of film thickness to slope length) is of the order of 10 −3 due to the isotropic patterning characteristics. Such a patterning scheme is also shown to remove non-aqueous poly (N-vinylcarbazole) (PVK) films coated in the presence of a bank structure. With the coating and patterning process, we have successfully fabricated multiple OLED stripes, an OLED device with the patterned light-emitting stripe, and OLED pixels, demonstrating its potential applicability to solution-processable OLEDs. • Suppressed lateral capillary flow by a hydrophobic needle for fine stripe coating. • Fabricated 54-μm-wide PEDOT:PSS stripe at a maximum coating speed of 30 mm/s. • Performed micro patterning of aqueous and non-aqueous thin films using double needles. • Achieved the pattern width of 260 μm and the pattern factor of 10 −3 using PEDOT:PSS. • Achieved light emission from OLED pixels and OLEDs with patterned or unpatterned stripes.

Underwater laser cutting of stainless steel up to 100 mm thick for dismantling application in nuclear power plants

For dismantling nuclear power plants, an underwater cutting study was conducted using a high power fiber laser. With a laser power of 9 kW, cutting tests were performed on stainless steel with a thickness of 50–100 mm. For this study, a waterproof cutting head consisting of a focusing element with a long focal length of 600 mm and a supersonic nozzle was used for high cutting efficiency. For thicknesses of 70 mm or less, it was possible to cut only with a single supersonic nozzle, while for a thickness of 80 mm or more, an initially pierced specimen or a double nozzle was required for successful cutting. Through these techniques, we were able to perform the cutting underwater up to a thickness of 100 mm. Furthermore, the kerf widths were as small as 1–2 mm, the amount of secondary waste will likely be small, which will reduce waste disposal costs.

Study on the Performance Improvement of Axial Flow Pump’s Saddle Zone by Using a Double Inlet Nozzle

The operating range of axial flow pumps is often constrained by the onset of rotating stall. An improved method using a double inlet nozzle to stabilize the performance curve is presented in the current study; a single inlet nozzle and three kinds of double inlet nozzle with different rib gap widths at the inlet of axial flow pump impeller were designed. Three dimensional (3D) incompressible flow fields were simulated, and the distributions of turbulence kinetic energy and velocity at different flow rates located at the inlet section, as well as the pressure and streamline in the impeller, were obtained at the same time. The single inlet nozzle scheme and a double inlet nozzle scheme were studied; the experimental and numerical performance results show that although the cross section is partly blocked in the double inlet nozzle, the head and efficiency do not decline at stable operation flow rate. On small flow rate condition, the double inlet nozzle scheme effectively stabilized the head-flow performance, whereby the block induced by the backflow before the impeller was markedly improved by using a double inlet nozzle. It has also been found that the rib gap width impacts the efficiency curve of the axial flow pump.

Computational study on reducing flow asymmetry in over-expanded planar nozzle by incorporating double divergence

Rocket nozzles accelerate combustion products or high pressure gases to supersonic/hypersonic velocities. The planar nozzles have rectangular cross-sections. At low altitude, the ambient pressure is higher than the exiting jet pressure, which leads to flow separation from the nozzle wall. In planar nozzles, asymmetric flow separation can be observed at low Nozzle Pressure Ratios. Asymmetric flow separation can lead to undesirable side forces. In the present study, numerical analysis is performed on the flow through planar nozzles. Nozzle geometries with different divergence angles and different double divergence having same area ratio are considered for flow analysis. The flow analysis is performed using commercial software ANSYS Fluent. All geometries are studied with similar boundary conditions. The numerical analysis is done on two-dimensional planar models. Reynolds Averaged Navier-Stokes, and Unsteady Reynolds Averaged Navier-Stokes equations are solved with realizable k-ε model turbulence model. The divergence angle of the nozzle having the same area ratio had a significant effect on the side load. It is found that as divergence angle increases the magnitude of side load decreases and flow becomes symmetry at low Nozzle Pressure Ratios. The design Mach number of the inner nozzle and extension length of double divergent nozzle is crucial for reducing the asymmetry of the flow. Shock reflection inside the nozzle due to discontinuity could be controlled by changing the divergence angle of the nozzle. The performance of the nozzle was seen to be augmented by introducing double divergence. The side load was profoundly affected by double divergence. It was also observed that, some double divergent nozzle had adverse side load. It was observed that asymmetry, unsteadiness, and side load of the flow was completely absent at inner nozzle having design Mach number of 1.3 for the double divergent nozzle having smaller extension length.

Super-twisting sliding mode control for aircraft at high angle of attack based on finite-time extended state observer

This paper proposes a finite-time decoupling control strategy for aircraft with thrust vector at high angle of attack maneuver. Firstly, the nonlinear mathematical model of the aircraft is presented. Taking into account the insufficiency of the aerodynamic control surface, a thrust vector model with double nozzles is added. Subsequently, a three-channel decoupling control scheme based on finite-time extended state observer is employed to realize the high angle of attack maneuver. Strong coupling among different channels, aerodynamic uncertainties and other unmodeled dynamics are regarded as total disturbance and estimated by a finite-time extended state observer. Super-twisting (SWT) sliding mode control is utilized to obtain expected performance and finite-time stability. The daisy chain method is adopted to realize the control allocation. Finally, the numerical simulations are provided to demonstrate the effectiveness and robustness of the proposed methodology.

A Double Nozzle Cross Flow Turbine Fluid Flow Dynamics

The dynamics of fluid flow are very important to the process of converting water energy into mechanical energy at the nozzle double runner cross flow turbine blade. Fluid dynamics of a jet of water from a nozzle release energy as the water crosses the cross flow turbine runner. This research aims to improve turbine performance and the effectiveness of fluid flow dynamics that drive cross flow turbine runner blades using double nozzles. The method of research using a cross flow turbine with double nozzle is a combination of vertical and horizontal nozzles. The turbine runner casing and blade are made of transparent acrylic material so that the flow dynamics can be observed directly. The laboratory scale double nozzle cross flow turbine is comprised of 24 blades, 3 mm thick, 40 mm long and 200 mm runner blade diameter. Test the performance of the turbine by measuring rotation, torque, and power, and by photographing the dynamics of the fluid flow that drives the turbine runner blade. The results of the study found that the visualization of the dynamics of fluid flow in turbines with double nozzles is more regular, evenly distributed, focused, and directed, moving the turbine runner blade cross flow so as to be able to increase turbine performance higher. The highest double nozzle cross flow turbine performance is 6.04 Watt power and 81.68% efficiency, at a water discharge of 0.22 liters /s.

Effects of Double Stage Venturi Scrubber Nozzle on the Liquid Injected Flow

Effects of Double Stage Venturi Scrubber Nozzle on the Liquid Injected Flow

Degradation of the cooling performance of the double wall nozzle guide vane in an engine

The overall cooling effectiveness of the original nozzle guide vanes and the vanes tested in engine operating for about one hundred hours was measured using infrared thermal imaging at a fan-shaped cascade pressure ratio of 2.378 and coolant-to-mainstream mass flow ratios of 0.0294–0.0784. Carbon dioxide was used as the coolant to provide density ratios of 3.2–4.2 and a dynamic viscous ratio of 0.8. The velocity magnitude of 57 m/s in the cascade inlet led to a Reynolds number of 624,000 based on the chord of the vane. About 5% turbulence intensity was recorded at the same location. The objective of the study was to determine the degradation of the cooling performance on the leading edge and trailing edge of the vane in an engine test. The results showed that the arc-averaged overall cooling effectiveness decreased by 0.03–0.17 depending on the various spanwise positions. The surface-averaged overall cooling effectiveness decreased by 0.08–0.13, 0.04–0.07 and 0.03–0.08 on the leading edge, impingement region and cut-back film cooling region of the trailing edge respectively. The values of the additional thermal resistance of the vane tested in the engine were determined by conducting a one-dimensional heat transfer model analysis based on the obtained experimental data of the overall cooling effectiveness.

Utilizing the inverse Marangoni convection to facilitate extremely-low-flow-rate intermittent spray cooling for large-area systems

An economical approach is required for solving the portability and maintenance problems of a spray cooling system for facilities stationed in remote areas. To reduce liquid consumption and decrease the number of nozzles required for large-area cooling, we propose the use of a self-rewetting fluid coupled with an intermittent spray that induces a surface-tension-driven flow to extend film evaporation. With an extremely low flow rate of 0.325 ml s−1, the working fluid can be effectively pulled toward a hot region through the inverse Marangoni convection, which promotes thermal uniformity and postpones dryout. Consequently, the cooling rate is considerably improved and the temperature fluctuation over time is reduced. Because of the extremely low liquid consumption, strong film evaporation and intensive nucleation, as opposed to impingement momentum, play major roles in cooling. Although multiple-nozzle configurations outperform single-nozzle configurations at high input power, the performance differentiation between double and quadruple nozzles is small, and excellent cooling can be achieved with a nozzle density as low as 0.10 cm−2. By using double or quadruple nozzles in the short-spray mode, the highest heat flux of 7.4 W cm−2 can be achieved with a temperature fluctuation of ±0.5 °C and spatial deviation smaller than 4%.

Concurrent multi-scale optimization of hybrid composite plates and shells for vibration

In this paper, a concurrent multi-scale optimization framework is established for hybrid composite plates and shells, where fiber volume, fiber orientation and stacking sequence can be optimized simultaneously. Firstly, a finite element model of shell structure that contains patches is established. Then, the candidate material set of hybrid composites is calculated and assembled by different combinations of fiber volume, fiber orientation and stacking sequence at the material and laminate scales. Furthermore, the Discrete Material Optimization (DMO) method is employed to perform the concurrent multi-scale optimization. Two illustrative examples are used to verify the effectiveness of the proposed optimization framework, including a simple example of a hybrid composite plate and a complex engineering example of a double serpentine nozzle. In comparison to optimal results by the traditional constant-stiffness design method, the optimal results of the proposed framework achieve significant 19.8% and 14.0% improvements in the fundamental frequency under the constraint of material cost, respectively. It can be concluded that the proposed concurrent multi-scale optimization framework has huge potential in adaptive stiffness tailoring for hybrid composite plates and shells with complex multi-scale design variables, which can make full use of hybrid composite materials to improve the structural performance against vibration while maintaining the low material cost.

Optimization of Nozzle Number, Nozzle Diameter and Number of Bucket of Pelton Turbine using Computational Fluid Dynamics and Taguchi Methods

Along with the depletion of fossil fuel reserves in Indonesia, water resources can be used as an alternative source of energy. Pelton turbines are one type of water turbine that can be used. However, Pelton turbines still have weaknesses in terms of determining the optimal number of buckets and nozzles. This study aims to optimize the experimental variations in the number of buckets (Nb), the diameter of the nozzle (Dj), and the number of nozzles (Nj) on the efficiency of the Pelton Turbine. The number of buckets was varied namely 24 and 27 pieces, nozzle diameter 5.5 mm and 7 mm, and number of nozzles using a single nozzle and double nozzle with horizontal direction. The research design began with Design of Experiment (DoE) using Taguchi method in Minitab 18.0. The next step was to calculate and then designed turbine using Autodesk Inventor 2016. The turbine design was then simulated using ANSYS Fluent 17.0 Workbench. The calculation of the largest efficiency using the number of 27 buckets double nozzle 5.5 mm producing an efficiency of 64, 69%. Based on Taguchi optimization delta result, the most influential variable on the efficiency was the nozzle diameter (M=0.1943).

Size-selected synthesis of metal nanoparticles by using electrospray in a liquid medium

Size selected synthesis of gold nanoparticle (AuNP) was carried out by use of an ultra-fine liquid droplet as a reaction field. The ultra-fine liquid droplets were generated by electrospraying in a liquid medium. The electrospraying in the liquid medium had a great advantage over the conventional electrospraying in the air. The size of electrosprayed liquid droplets can be varied with the supplied electric voltage beyond the range of the electrospraying in the air. When the AuNPs synthesis through the chemical reduction of Au3+ was carried out by use of this electrospraying in the liquid medium for the mixing of Au3+ solution and the reducing agent solution, the size of AuNPs was controlled by the supplied electric voltage. Two types of reaction field equipped with a single and double electrospray nozzles were designed to be demonstrated.

Bubble Size Distribution Characteristics of a Jet-Stirring Coupling Flotation Device

In this study, a new jet-stirring coupling flotation device that incorporates the advantages of three conventional flotation machines (specifically, Jameson cell, mechanical flotation cell, flotation column) was designed based on jet suction. The suction capacity of a double cosine self-aspirated nozzle utilized by the device was analyzed under different feeding pressures, and the effects of frother concentration, feeding pressure, suction capacity, and height of sampling location on the bubble size distribution (BSD) were investigated using a high-speed video system. It was found that a large amount of air was sucked into the flotation cell by the self-aspirated nozzle arranged in a non-submerged manner, which met the requirements of flotation in terms of the suction amount of air. The suction capacity showed a positive linear correlation with negative pressure inside the nozzle. When the Methyl isobutyl carbinol (MIBC) concentration reached the critical coalescence concentration (CCC), the bubble size stabilized at approximately 0.31 mm, which was smaller than the bubble size produced by the conventional flotation machine. This indicated that bubbles suitable for flotation were generated. D32 linearly decreased with increasing of feeding pressures and conversely increased with increasing suction capacities and sampling location heights, independent of the frother concentration.

Design and evaluation of an embedded double jet nozzle for MQL delivery intending machinability improvement in turning operation

Minimum quantity lubrication (MQL) is a promising solution as an alternative to conventional flood cooling and dry machining. It is a bridging technology between the dry and conventional flood cooling. In this work, an embedded double jet nozzle has been designed and developed for enhancing the effectiveness of MQL. Grey based Taguchi multi-response optimization was applied to find out the MQL parameters (i.e. nozzle size, nozzle angle, air pressure and oil flow rate) for reducing cutting temperature, surface roughness, chip reduction coefficient and main cutting force. Consequently, the MQL and nozzle parameters were ranked. In this regard, Taguchi's orthogonal array (L18) was used for experimental design. GRA (Grey relational analysis) was employed to convert the multiple objectives (responses) into a single objective and finally, Taguchi's S/N ratios were used for optimization. The analysis results demonstrated that the most influential factor for an optimum response was nozzle diameter followed by air pressure, secondary nozzle angle, oil flow rate and primary nozzle angle and their optimum values are 1 mm, 19 bar, 15°, 80 ml/h and 20° respectively. A confirmation test was conducted to verify the feasibility of using a grey-based Taguchi optimization method. In the final part of this work, the performance of double jet MQL micro nozzle was compared against dry machining and single jet MQL machining and found most effective among three machining condition regarding cutting temperature, surface roughness, chip reduction coefficient, main cutting force and tool wears in turning medium carbon steel by coated carbide insert. A supplementary benefit of this simple embedded double jet nozzle is set up time minimization and consistent cooling without extra supervision.

Study on Pressure Coefficient in Process of Double Slot Nozzle Jet Impingement on Sinusoidal Colliding Strip

Air cushion furnace is widely used in the heat treatment process of aluminum strip, copper strip and silicon steel, and the double slot nozzle is the core part of the air cushion furnace device. Studying the distribution characteristics of the surface pressure coefficient of the strip during the suspension process could provide important theoretical references for the high-efficiency and high-value production of the air-cushion furnace. In this paper, the distribution of pressure coefficients is studied under the conditions of Re=48 194~12 048, high H/D=1~3, spacing L/D=17.2 and sinusoidal amplitude A=0~30 mm. The results show that with the decrease of L/D, the position of the main stop point moves to the center line of the nozzle, and the value of the second stop point increases gradually, and with the increase of the sinusoidal amplitude A, the position of the main stop point moves gradually to x/D=0. The pressure coefficient Cp decreases with the increase of sinusoidal amplitude A, the pressure coefficient Cp decreases with the increase of H/D, and the difference between the pressure coefficient at the stationary point of the double-slot nozzle and the pressure coefficient at the non-stationary point increases with the increase of H/D. This study provides an important theoretical basis for the design of double slot nozzles in air cushion furnace.

Parametric Design Method and Performance Analysis of Double S-Shaped Nozzles

A parametric design method, which was based on super-elliptical transition and self-adaption infrared radiation shield for the double S-shaped nozzle, was introduced. The complete shielding of high-temperature components in the S-shaped nozzle was realized. Model experiments and numerical simulations were performed to investigate the effects of offset ratioS/D, the ratio of length to diameterL/D, and the aspect ratioW/Hon the aerodynamics and infrared radiation. The results showed that the total pressure recovery and thrust coefficients were improved initially, but dropped rapidly with the increase in offset ratios with the range of investigated parameters. There existed an optimal offset ratio for the aerodynamic performances. Considering the weight penalty, the length of nozzles should only be increased properly to achieve better aerodynamic performances. Both friction and viscous losses caused by large streamwise vortices dominated the aerodynamic performances of nozzles. The nozzle with the aspect ratio ofW/H=5.0was recommended for achieving optimal aerodynamics. The increase in aspect and offset ratios could effectively suppress plume radiation, which was, however, not sensitive to overall radiation. Compared to circular nozzles, double S-shaped nozzles reduced overall infrared radiation by over 50%, which proves significant stealth ability. A balance between aerodynamic performances and infrared radiation suppression could be reached for double S-shaped nozzles.