Nozzle In Order Research Articles

Convergent Divergent Nozzle Design and Analysis to Increase Working Effectiveness

Abstract: Our project's major goal is to develop and examine a Convergent- Divergent rocket nozzle in order to lower nozzle costs. Here, convergent divergent nozzle uses an alternative material. The design is based on earlier designs that served as a guide for our own. A nozzle is a crucial component that merits consideration in this era of expanding rocket propulsion for a variety of uses, including the launch of satellites into space or human missions. With this in mind, a fundamental design is created utilising the understanding of compressible flow, and the resulting thrust is estimated. use the layout established by hand computations. Utilising the ANSYS Fluent programme, the work is done in, the calculations and results are validated.

Conceptions and Feasibility Study of Fiber Orientation in the Melt as Part of a Completely Circular Recycling Concept for Fiber-Reinforced Thermoplastics

Fiber-reinforced thermoplastics are an important construction material for lightweight applications. The increasing use of especially glass fiber-reinforced plastics leads to growing amounts of not recyclable composite materials, which is commonly disposed of by landfilling. Hence, there is a need for a recycling concept for glass-fiber-reinforced plastics that enables their complete reuse over many recycling cycles. In this paper, such a recycling concept is presented, which is based on the idea of melting the whole glass-fiber-reinforced component without prior size reduction. The fiber-reinforced melt will be pressed through a nozzle in order to achieve a strand with highly oriented fibers that can then be applied in new components via a tape-like laying process. The feasibility of the recycling concept is proved in this paper. Therefore, investigations on the reorientation of fibers in the melt by pressing through a rectangular nozzle have been carried out with different nozzle diameters, shear rates and melt temperatures. The investigations result in a stable process, which enables an increase in fiber orientation of about 37% up to a mean fiber orientation of 67% in the flow direction. These findings are independent of the initial fiber orientation.

Effect of nozzle shape and applied load on jet injection efficiency

In this paper we present new results on jet injection with the overall aim of providing an efficient drug delivery into the intradermal region of the skin. To advance upon previous work in this area, we studied the use of various geometries for the nozzle (ampule) tip, which is applied to the skin. The geometries included a regular (flat-top) nozzle, tapered nozzles (conical and parabolic), and one wide base nozzle in order to vary the local stress in the skin layers directly beneath the injector. In all of these geometries, we also varied both the applied load and the skin support (e.g., solid backing vs. porcine tissue). We found that the use of applied load combined with a wider contact area led to more consistent injections with dispersion characteristics that may be preferable for vaccinations utilizing skin-based electroporation.

An improved vacuum-steam pulsed blanching machine design and garlic scape blanching verified experiment

Vacuum-steam pulsed blanching (VSPB) is an emerging blanching method resulting in high efficiency and product quality. However, inconvenient loading, small loading capacity, uneven rinsing and imprecise control hinder its application in food industry. Therefore, the current work aimed to design a VSPB machine, including selection of components, building a control system and designing a steam nozzle in order to increase the load capacity and improve device control. For this purpose, a horizontal blanching chamber with internal nozzle was designed and optimized using CFD method. The vacuum chamber design required a more evenly distributed steam inlet. A water-sealing vacuum pump, a cooling device and a hardware system were developed. The distribution of steam released from the nozzle in the chamber was numerically investigated by solving the three-dimensional Reynolds-averaged Navier-Stokes equations, with a velocity uniformity index value of 0.448. The validation blanching test was conducted using garlic scape as the test material. The steam holding time and the number of cycles significantly affected (p < 0.05) the color of the garlic scapes. Peroxidase (POD) activity decreased with the increase of blanching cycles until the enzymes were completely inactivated. VSPB significantly decreased (p < 0.05) the lignin content of the garlic scapes. The findings indicate that the best results were obtained after 2 cycles of VSPB and steam holding time of 30 s. Industrial relevanceHot water and steam thermal blanching are the two most frequently used blanching methods in food processing. Generally, they are used as a pretreatment before drying, freezing or canning of different fruits and vegetables. In current work, an improved vacuum-steam pulsed blanching machine was designed and the validation blanching test with garlic scape as the material indicated that VSPB operation was effective in preventing the synthesis of lignification in garlic scapes. By considering enzyme inactivation, lignification, color, and other quality attributes, 2 cycles of VSPB and steam holding for 30 s were proposed as the optimal VSPB conditions.

On the possibility of flight of a single-stage rocket to the planets of the Solar system

A new concept for building a small-sized rocket engine containing a special gas ionizer in the combustion chamber to increase its conductivity to an optimal value with a corresponding improvement in the fuel combustion process is proposed. A simplified calculation for the relative velocity of gases in a conical nozzle is given when heating the supersonic flow of gases by plasma in a conical nozzle by means of a powerful, electromagnetic, high-frequency field, and the influence of some technical parameters on the efficiency of the rocket's flight is also considered. A comparison of the flight altitude of a rocket with plasma heating of the gas flow in a conical nozzle with a scale model corresponding to the well-known single-stage Zenit rocket with the same weight and geometry, taking into account air resistance for the cargo version of the rocket with one small-sized engine, is made. The result is a significant reduction in fuel consumption and an increase in the maximum flight altitude by 2 times with an increase in specific impulse by 2.7 times, other things being equal. It is established that under certain conceptual parameters, it is possible to rapidly accelerate and fly a single-stage cargo rocket with a launch weight of 17.25-20.00 tons to the planets of the solar system directly from the Earth's surface using a bunch of engines of the same type. The use of many of the same type of small-sized engines allows you to abandon the Laval nozzle in favor of a simple conical nozzle, which reduces the size of the rocket as a whole. This is determined by the need to reduce the diameter of the conical nozzle in order to achieve a greater specific heating power of the plasma compared to the specific power of the fuel burned in the combustion chamber. It is also proposed a complete rejection of the steering engines, the function of which will be performed by part of the engines located closer to the diameter of the rocket. As electric generators, it is proposed to use promising prototypes of electric generators MEG-6NS, MEG-15NS and others, the company "NaukaSoft", with good weight indicators that allow in the future to produce such a liquid rocket engine of small dimensions. The redistribution of part of the fuel used to produce electricity is compensated by a significant increase in the specific impulse of the liquid rocket engine to increase the speed and overall efficiency of the flight with an optimal ratio of the amount of fuel to the weight of the rocket before refueling.

A-Variant Design of Hypersonic Ludwieg Tube Wind Tunnel

To improve the operation efficiency of conventional Ludwieg tube tunnel, a fast-acting valve is usually deployed between the storage tube and Laval nozzle in order to separate the high- and low-pressure air. However, the disturbance produced by the fast-acting valve as well as the nonuniform heating of storage tube affects the flow quality of the hypersonic Ludwieg tube. Stimulated by the motivation of overcoming the mentioned problems, the feasibility of a novel configuration of hypersonic Ludwieg tube is explored in this research. Upon this study, we introduced an additional Laval nozzle and settling chamber to the conventional Ludwieg tube tunnel, while the cross-section area of the main Laval nozzle is smaller than that of the introduced Laval nozzle. To begin with, the flow evolution along the dual-throat Ludwieg tube was analyzed theoretically; subsequently, numerical simulations were conducted to study the starting process of the dual-throat Ludwieg tube tunnel, and emphasis was placed on the influence of different throat area ratios and settling chamber lengths upon the startup time of wind tunnel. Lastly, the flowfield of the dual-throat Ludwieg tunnel was characterized by measuring the Mach number distribution and pitot pressure fluctuation in the test section as well as the pressures along the overall tunnel. The results show that this novel configuration of Ludwieg tube is applicable and it offers the opportunity for flow quality improvement for conventional Ludwieg tubes with small penalty of reducing the tunnel’s efficient running time.

Дослідження перебігу допалювання в порожнині робочого простору кисневого конвертера за рахунок оцінки фізичних параметрів димових газів та полум’я

The work is devoted to the development and evaluation of the effectiveness of an available method of monitoring the state of the converter bath based on the physical parameters of the flame formed during the afterburning of the source gases. In the process of purging in the oxygen converter, conditions are created for the oxidation reaction of CO to CO2 in the cavity of the unit. Control of the specified factor can allow corrective actions to be taken to ensure a high level of technological and environmental indicators and be an indicator of the completeness of the flow of chemical transformations in the cavity of the oxygen converter. according to the luminosity of the gas torch in different spectrum; by the electrical conductivity of the gas torch. The conditions of different conditions of the high-temperature environment are taken into account: dustiness; fractions of dust emitted from the converter and their chemical composition, completeness of combustion when different fractions of the oxidizer are supplied. Simulation of the state of the environment in the upper part of the oxygen converter was performed. It was established that the most influential negative factor in the assessment of afterburning is dust, which affects all physical parameters of the flame and at high temperatures of the process itself becomes an object of radiation of both heat and light. According to the results of the research, it was concluded that it is most appropriate to measure the electrical conductivity of the flame between the torch and the blowing nozzle in order to have more complete information about the afterburning processes. When evaluating the operation of the blowing device, it was established that the dependence of the electrical conductivity of the flame on the CO content can serve as a characteristic of afterburning indicators and has a typical quadratic character.

Computational steady-thrust vector controlsupersonic secondary flow injection

This paper presents the Computational study of flow through the Rocket Nozzle in order to manoeuvre the Rocket by means of Supersonic Secondary Injection of Hot gases. Well-designed nozzles can accelerate these gases to speeds of thousands of meters per second. In addition to accelerating the gases, nozzles are often responsible for steering (or “vectoring”) the flow in order to control the rocket’s direction of flight. Due to continuous secondary injection of hot gases, the strong unsteady effects like Shear Layers, Intervention of Shockwaves with the Core fluid flow, Biased Wall Shear, etc., has to be studied precisely to appraise/evaluate the effectiveness of Nozzle contribution in role of steering the Rocket. Numerical Technique/Computational Analysis has been carried out to provide tons of insight about the meticulous behavior of Fluid particles while they interact with secondary flow. Comparative study on Supersonic Fluid Flow and the intervention of Secondary Injection of Hot gases has been carried at different angle of injection and at different injecting Pressure in order to find its optimum injection angle and optimum Injecting Pressure. It has been observed that Steering of Rocket drives well by Secondary Injection when its injecting angle becomes tangential to fluid flow direction and Injecting Pressure favors to steer the rocket when it increases its magnitude.

The Effectiveness of Microbubble Technology in The Quality Improvement of Raw Water Sample

An experimental study to observe the performance of microbubble generator (MBG) and microbubble-generating nozzle on water is carried out under laboratory conditions. The MBG is used to treat wastewater from water bodies which was impacted by domestic and industrial wastewater. The study uses MBG with a spherical body and a drilled hole, along with a dispersing nozzle placed at the bottom of microbubble reactor tank. The MBG used is considered to be more applicable for water bodies rather than other types. Two types of pressure gauges are installed around the MBG and the nozzle in order to examine and configure the inlet water pressure and the inlet gas pressure based on the best microbubble size produced from a prior experiment. Biological Oxygen Demand (BOD), Chemical Oxygen Demand (COD), Dissolved Oxygen (DO), Total Suspended Solids (TSS), and Turbidity has been analyzed in the beginning and every 10 minutes of a 60 minute detention time to examine the effectiveness of MBG. The results of study shows the MBG have a high rate of removal percentage in a 60-minute retention time with 60 to 90% for TSS, up to 90% for Turbidity, 74 to 96% for BOD, and 41 to 59% for COD.

Cavitation patterns in high-pressure homogenization nozzles with cylindrical orifices: Influence of mixing stream in Simultaneous Homogenization and Mixing

High-pressure homogenization is the state of the art to produce high-quality emulsions with droplet sizes in the submicron range. In simultaneous homogenization and mixing (SHM), an additional mixing stream is inserted into a modified homogenization nozzle in order to create synergies between the unit operation homogenization and mixing. In this work, the influence of the mixing stream on cavitation patterns after a cylindrical orifice is investigated. Shadow-graphic images of the cavitation patterns were taken using a high-speed camera and an optically accessible mixing chamber. Results show that adding the mixing stream can contribute to coalescence of cavitation bubbles. Choked cavitation was observed at higher cavitation numbers σ with increasing mixing stream. The influence of the mixing stream became more significant at a higher orifice to outlet ratio, where a hydraulic flip was also observed at higher σ. The decrease of cavitation intensity with increasing back-pressure was found to be identical with conventional high-pressure homogenization. In the future, the results can be taken into account in the SHM process design to improve the efficiency of droplet break-up by preventing cavitation or at least hydraulic flip.

Optimization of fused deposition modeling process using a virus-evolutionary genetic algorithm

Fused Deposition modelling (FDM) is one of the most widely used Additive Manufacturing technologies that extrude a melted plastic filament through a heated nozzle in order to build final physical models layer-by-layer. In this research, a virus-evolutionary genetic algorithm (MOVEGA) is developed and implemented to solve a multi-objective optimization problem related to fused deposition modelling. Taguchi approach was first employed for the experimental procedure design and nine test parts were built according to L9 orthogonal array. The examined process parameters were the deposition angle, layer thickness, and infill ratio each one having three levels. Infill pattern was constant to honeycomb selection. Fabrication time of ABS (Acrylonitrile-Butadiene-Styrene) 3D printed specimens was measured during experiments and analyzed by using Analysis of Means (ANOM) and Analysis of Variance (ANOVA) techniques. Shape accuracy was measured by considering the parts’ dimensions in X, Y and Z axes and expressed as the overall error for control. Regression models were developed to use them as objective functions for a group of multi-objective optimization algorithms. Multi-objective Greywolf (MOGWO), and multi-universe (MOMVO) algorithms where also selected for optimizing the FDM problem to compare results. To evaluate the algorithms and judge superiority with reference to the non-dominated solution sets obtained, the hypervolume indicator was adopted. It has been verified that MOVEGA exhibited superiority in its performance for optimizing FDM problems when compared to heuristics such as MOGWO and MOMVO algorithms whilst it has strong potentials to be coupled with “Internet of Things” (IoT) platforms to facilitate the intelligent optimization control referring to a range of resources, consumables and software.

The Effect of Hydraulic Conditions in Barbotage Reactors on Aeration Efficiency

Barbotage reactors such as airlift reactors (ALR) and bubble column reactors (BCR), due to their two-phase flow systems, were investigated in many research papers. In their basic design variants, they are typically used to lift, mix, and aerate liquids, while, when equipped with additional elements in hybrid variants, their individual properties, i.e., lifting, mixing, and aeration of liquids, can significantly change with the same reactor geometry. The object of this study was to develop a hybrid barbotage reactor in various structural design variants. The structure consisted of a barbotage column of 50 mm in diameter, used to transport a water–air mixture outside the reactor (so-called external loop). The installation was additionally equipped with a nozzle in order to improve mixture aeration and circulation efficiency. The nozzle was mounted at various heights of the column pump segment. Additionally, the reactor was equipped with s moving bed in two variants (20% and 40% reactor capacity) in order to determine its effect on the mixture aeration and circulation conditions. Based on the measurement results, aeration curves were prepared for various structural design and column packing variants of the reactor. Properties of the two-phase mixture were determined for both parts—ALR and BCR. Technological and energy parameters of the aeration process were calculated, and the results obtained for the individual structural design variants were compared. It was found that, for the most advantageous design, in terms of aeration efficiency, the aeration nozzle should be placed in the mid-length of the pump segment of the barbotage column, irrespective of the hybrid reactor packing rate with the moving bed. The reactor packing with the moving bed resulted in a decreased mean water velocity in the reactor. For most analyzed structural design variants, the respective packing with the moving bed had no significant effect on aeration efficiency. Only for one structural design variant did the lack of packing significantly improve oxygen levels by as much as approximately 41%.

Combustion Characteristic of Offset Orifice Nozzle under Multi Pulse Ultrahigh Pressure Injection and PCCI Combustion Conditions

&lt;div class="section abstract"&gt;&lt;div class="htmlview paragraph"&gt;CI engines provide higher thermal efficiency compared to other internal combustion engines. On the other hand large amounts of smoke and NO&lt;sub&gt;x&lt;/sub&gt; are produced during combustion. Smoke and NO&lt;sub&gt;x&lt;/sub&gt; can be reduced by applying Premixed Charge Compression Ignition (PCCI) combustion. Unfortunately, the problems of PCCI combustion include unstable start of combustion and limited operating range. The multi-pulse ultrahigh pressure injection allows fuel to control PCCI combustion. The objective of offset orifice nozzle is to improve mixture formation and shorten spray penetration in order to increase thermal efficiency and control PCCI combustion. The offset orifice nozzle was designed by shift orifice aliment from into the sac center to edge of sac follow swirl direction. Counter bore design was applied to offset orifice nozzle in order to keep the constant orifice length as standard nozzle. This paper investigates the effect of nozzle orifice design on combustion characteristics under multi pulse ultra high pressure injection and PCCI combustion conditions. The experiments were carried out on a single cylinder engine at 0.55 MPa gross IMEP at 1,750 rpm. The injection pulses were 3 pulses equally mass main injection at 150, 200, 250, 300 and 350 MPa injection pressure. In case of standard nozzle orifice, 1&lt;sup&gt;st&lt;/sup&gt;, 2&lt;sup&gt;nd&lt;/sup&gt; pulse are PCCI followed by diffusive combustion in every injection pressure. For offset orifice nozzle orifice at 150 and 200 MPa 1&lt;sup&gt;st&lt;/sup&gt;, 2&lt;sup&gt;nd&lt;/sup&gt; pulse are also PCCI combustion. However when injection pressure is over 200 MPa, the 2nd pulse of rate of heat release become diffusive combustion. The offset orifice nozzle resulted in increased thermal efficiency, NO&lt;sub&gt;x&lt;/sub&gt; and smoke. However significant differences between the smoke of offset orifice nozzle and standard nozzle were not found under injection pressure 300 and 350 MPa. The offset orifice nozzle also resulted in decrease CO and THC.&lt;/div&gt;&lt;/div&gt;

Speciation of VOCs in the cooking fumes from five edible oils and their corresponding health risk assessments

Cooking fumes are important volatile organic compounds (VOCs) sources of indoor air, however, emission characteristics of the commonly used oils (canola, soybean, peanut, corn and lard) in Chinese cooking and health risks of the corresponding VOCs are still not clear. In this study, we sprayed the oil droplets uniformly on a pre-heated wall via a nozzle in order to obtain the cooking fumes with constant VOC compositions. Our results show that emission profiles of VOCs are similar among the five oils. The vegetable oils rich in unsaturated fatty acids emit more VOCs than the lard oil rich in saturated fatty acids, and the VOCs emitted from the soybean oil increase with increasing cooking temperatures. Water in oils always enhances VOC emissions by steam stripping at high temperatures. Moreover, oxidative radicals generated in the water-oil system facilitate oxidation of unsaturated fatty acids, producing carcinogenic aldehydes, benzenes and furans in the emitted VOCs. The carcinogenic risk order of furan > nonanal > hexanal > heptanal > octanal> 2-nonenal > benzene indicates that furan and various aldehydes are more carcinogenic than benzene compounds. The comprehensive health risk factor further reveals that the carcinogenic risks of the emitted VOCs from the five oils follow the order of peanut > canola > soybean > corn >> lard.

Installation aerodynamics of civil aero-engine exhaust systems

Without careful consideration of aerodynamic installation effects on exhaust system performance the projected benefits of high bypass ratio engines may not be achievable. This work presents a computational study of propulsion system integration in order to quantify the effect that aircraft installation has on the aerodynamic performance of separate-jet aero-engine exhaust systems. Within this study the sensitivity of exhaust nozzle performance metrics to aircraft incidence and under wing position were investigated for two engines of different specific thrust. Upon installation, thrust generation was found to be beneficial or detrimental relative to an isolated engine depending on the position of the engine relative to the wing leading edge. The dominant installation effect was observed on the exhaust afterbodies and, over the range of engine positions investigated at cruise conditions, the installed modified velocity coefficient was shown to vary up to 1% relative to an isolated engine. Furthermore, due to variations in the core nozzle mass flow rate by up to 10% relative to an isolated engine, it is concluded that aerodynamic installation effects need to be taken into consideration when sizing the core nozzle in order to ensure engine operability.

Experimental evaluation of nozzles to mitigate liquid loading in gas wells

An optimally designed nozzle can be used as an efficient artificial lift system to deliquify gas wells. The objective of this work is to determine the most optimum nozzle parameters and geometry that would maximize critical pressure ratio while minimizing pressure drop across the nozzle under two-phase flow conditions. Six optimum nozzle geometries, evaluated under single-phase flow conditions in a previous study, are evaluated in this work. Two separate facilities were used to conduct the two-phase (air and water) experiments: a horizontal facility with 1.5 in. inner diameter (ID) PVC pipelines and a 30 ft long lateral pipeline section, and a vertical facility with 1.5 in. ID PVC pipelines and a 30 ft long vertical pipeline section. The horizontal facility was used to study the effect of introducing water into the system as a second phase, and the vertical facility was used to simulate conditions of a gas well with a nozzle installed as an artificial lift system. Horizontal flow experimental results showed that critical pressure ratio decreases for two-phase flow relative to single-phase flow. The distance of the annular churn flow pattern observed downstream the nozzle may be related to the nozzle performance; significantly lower performance was observed for the LJ nozzle in two phase horizontal testing relative to other nozzles – one characteristic this might be attributed to is the peculiarly longer distance of downstream annular churn flow pattern observed for this particular nozzle compared to other nozzles. Based on data analysis, the ASTAR nozzle group showed the most improved performance, similar to results obtained in single-phase horizontal testing. Based on vertical experimental results, the most optimum nozzle geometry to deliquify a loaded gas well was identified as the ASTAR nozzle 2, a parabolic nozzle geometry. A significant temperature drop downstream the nozzle was observed during these experiments. It is important to account for temperature change while designing a nozzle in order to avoid flow assurance problems, such as gas hydrate formation. The trends observed in relative performance between different nozzle geometries (rankings based on critical pressure ratio and pressure drop) for two-phase vertical experiments were similar to those observed for single-phase horizontal experiments. Therefore, single-phase experiments could be sufficient to evaluate relative nozzle geometry performance based on critical pressure ratio, for the conditions used in this study.

The study of ultrasonic vibration assisted polishing optical glass lens with ultrasonic atomizing liquid

In this paper, our study is ultrasonic vibration assisted polishing optical glass lens with ultrasonic atomizing liquid. The ultrasonic vibration is applied to the axial direction of the main shaft, which can make abundant grains to impact the workpiece with the high-frequency reciprocating style. And the ultrasonic atomizing liquid is applied to the nozzle in order to make grains more homogeneous and decrease clustering phenomenon, which can improve the surface quality. The material removal rate model of single and multiple grains in the holes and micro-peaks of the polishing head are established by analyzing the removal mechanism of ultrasonic vibration assisted polishing for optical glass lens with ultrasonic atomizing liquid. Several sets of experiments were designed and the optical glass lenses were polished through contrast experiment. The contrast experiment results show that the material removal rate of ultrasonic assisted polishing of optical glass lens with ultrasonic atomizing liquid is better than that of one-dimensional ultrasonic assisted polishing and common polishing. And the surface roughness of ultrasonic vibration assisted polishing with ultrasonic atomizing liquid can reach 2 nm. And the results of experiments can be seen that the removal rate of the material is related to the abrasive grain diameter, the rotational speed and the feed rate of polishing head, and the ultrasonic amplitude. The experimental results are basically consistent with the prediction model.

Numerical Modeling and Heat Transfer Analysis of Minimum Quantity Lubrication Grinding of Inconel 751

Sustainable Manufacturing has gained a widespread acceptance in today's manufacturing industry. This paper accentuates the need for environment-friendly lubrication with the help of Minimum Quantity Lubrication or Near Dry Machining. Minimum Quantity Lubrication (MQL) uses an atomizing nozzle in order to create fine droplets which on hitting the hot machining zone dissipates the heat and provides lubrication. In contrast to the flood coolant, MQL technology increases the surface area of contact with each droplet hence optimizing the coolant to the maximum extent by reducing harmful fumes, improving cutting performance and favorably reducing coolant consumption. Due to the rotating grinding wheel, a hydrodynamic boundary layer is formed around it, producing a back air flow which possesses enough momentum to oppose the incoming cutting fluid, restricting it to reach the machining zone. Thus, it is of prime importance to penetrate this air cushion forming the boundary layer to effectively cool and lubricate the grinding region. This could be only achieved when the oil droplet velocity is significantly greater than the grinding wheel's tangential velocity. In this work, various parameters including droplet size & velocity have been determined for improving the spray on the basis of flow rate and inlet air pressure in MQL nozzle using commercially available CFD solver Ansys Fluent. Further, Heat Transfer Modeling is also carried out both computationally and analytically in order to find the heat taken away by the MQL oil. The computational results validated the experimental analysis carried out for the droplet diameter and analytical model for the heat flux. Multiphase model DPM was preferred over VOF since it tracks each and every parcel coming out from the injection surface within the computational domain. The oil droplet size if found to be a function of air pressure and flow rate of the atomizer and the Heat flux on workpiece decreased with increase in oil flow rate.

A study of the cooling systems and fluid flow simulation in metal cutting processing

This paper analyzes several types of cooling agents, their properties and how they can be chosen for a better heat dispersion resulting from the cutting process. An excessive heat in the cutting zone leads to excessive wear of the cutting tools, that leading finally to additional costs of their acquisition and due to wear is reached in cutting process more irregular surfaces. The coolant chosen can be a combination of different cooling fluids from the most simple and inexpensive to more complex, the difference between them being more appropriately cool the processing area. The fluid flow parameters of coolant can be influenced by the nature of the fluid or fluids used, the geometry of the nozzle in order to achieve a better dispersion of the lubricant on the area to be processed. A smaller amount of fluid is important in terms of the economy lubricant, because some of these lubricants are quite expensive. A minimal quantity of lubricant (MQL) may have a better impact on the environment and the health of the operator because the coolants in contact with overheated machined surface may develop a substantial amount of these gases that are not always beneficial to health.

Water monitoring by optofluidic Raman spectroscopy for in situ applications

The feasibility of water monitoring by Raman spectroscopy with a portable optofluidic system for in-situ applications has been successfully demonstrated. In the proposed approach, the sample under analysis is injected into a capillary nozzle in order to produce a liquid jet that acts as an optical waveguide. This jet waveguide provides an effective strategy to excite and collect the Raman signals arising from water contaminants due to the high refractive index difference between air and water. The proposed approach avoids any necessity of liquid container or flow cell and removes any background signal coming from the sample container commonly affects Raman measurements. Furthermore, this absence is a significant advantage for in situ measurements where fouling problems can be relevant and cleaning procedures are troublesome. The extreme simplicity and efficiency of the optical scheme adopted in our approach result in highly sensitive and rapid measurements that have been performed on different representative water pollutants. The experimental results demonstrate the high potentiality of our device in water quality monitoring and analysis. In particular, nitrate and sulfate are detected below the maximum contamination level allowed for drinking water, whereas a limit of detection of 40mg/l has been found for benzene.