This paper presents a stable numerical design method for a supersonic nozzle by the introduction of an original analytical expression for the pressure drop on the axis of the nozzle. The figures show the regularity of the change of the characteristic parameters along the nozzle. Furthermore, by introducing an analytical expres- sion for the pressure distribution it is easily possible, by selecting a coefficient b in equation (14), to design both a longer and a shorter nozzle. The research is also applica- ble to two-dimensional and annular nozzles. These re- sults agree well with the calculation using the application code FLUENT for the obtained shape of the nozzle. V kritiènem prerezu:
A chevron spout was structured by accepting the united spout as a source of perspective. The chevrons are designed as expansions to the 60mm distance across joined spout with a five-degree edge of entrance into the stream. The total length of the chevron nozzle was 214 mm. The spout leave proportional zone, created by the anticipated downstream zone, has been reduced due to infiltration. Another convergent nozzle had also been fabricated with a length of 194mm.
Hope that this study will help to discover, design, and analyze the common problem of spray nozzle application and able to propose the better nozzle especially the spiral nozzle type. This study will focus more on the external design of the nozzle rather than the internal. In the end, the main usage of the nozzle that been studied will be useful for the dish wash spray application.
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Abstract- Nozzle is a device designed that control the rate of flow, speed, direction, mass, shape and pressure of the stream that exhaust from it. Nozzles have variety of shapes and sizes depending on the mission of the rocket. Nozzles is very important for the understanding the performance characteristics of rocket. The proper geometrical design of the nozzle, the exhaust of the propellant gases will be regulated in such a way that max effective rocket velocity can be reached. Convergent divergent nozzle is the most commonly used nozzle. Objective of this work is to determine the optimum Nozzle parameters such as Divergent angle for a rocket nozzle. CFD simulation has been made using ANSYS FLUENT with appropriate Boundary condition.
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To engineer an efficient process, the parameters and the nozzle design were studied carefully. In the mid to late 1990s, Dykhuizen and Smith  quantified the increasing effect of the particle velocity on the Deposition Efficiency (DE) and used it for a nozzle optimisation calculation. DE quantifies the efficiency of the process by comparing the proportion of deposited particle mass over all injected particle mass . Dykhuizen and Smith used a one-dimensional isentropic flow assumption and a drag law to determine the particle velocity as a function of the gas properties, as well as the particle material and size. In addition, they stated that the performance is more sensitive to the nozzle length than its shape. These calculations are often referred to as the basis for numerical models of the time.
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Lecturer, Department of Mechanical Engineering, Government Polytechnic Awasari, Maharashtra, India ----------------------------------------------------------------------***--------------------------------------------------------------------- Abstract - Recently there is consistent research in machining and advancement in innovation. With increment in rivalry in advertise and to accomplish high exactness now a day the non-traditional machining is moved toward becoming help of any industry. A standout amongst the most imperative non-customary machining strategies is CNC plasma Machining. Its high precision, completing, capacity of machining any hard materials and to create mind boggling shape builds its request in showcase. In proposal work writing has been examined in setting to parametric improvement of CNC plasma Machining. With a specific end goal to achieve target and ideal outcomes, after find the optimization parameter the moved towered the optimization in size (design parameters) and minimum wear of nozzle. The fitting orthogonal cluster has been chosen according to number of components and their levels to perform least experimentation. The work bits of mile Steel materials were utilized for explore reason. While optimizing a plasma arc cutting nozzle design parameters to minimize the wear, several but selective machine process parameters and nozzle design parameters given by the various stack holders. This experimentation includes the process parameters as specifications given by manufacturer, dimensional accuracy report, roughness parameters analysis, material removal rate analysis and n addition to this, nozzle design parameters after burning the nozzle as, nozzle shell diameter, nozzle length, nozzle inner shell center pin diameter etc. Experimentation and parameters analysis comes about are given to affirm the viability of this approach.
In theory, the only important parameter in missile nozzle design is the expansion area ratio (e), or the ratio of exit area (A exit) to throat area (A Throat).Fixing all other variables (primarily the chamber pressure), there exists only one such ratio that optimizes overall system performance for a given altitude (or ambient pressure). However, a missile typically does not travel at only one altitude. Thus, an engineer must be aware of the trajectory over which a missile is to travel so that an expansion ratio that maximizes performance over a range of ambient pressure can be selected. Nevertheless, other factors must also be considered that tend to alter the design from this expansion ratio-based optimum. Some of the issues designers must deal with area nozzle weight, length, manufacturability, cooling (heat transfer), and aerodynamic characteristics.
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1000 rpm and 18.4 respectively. In this paper, detail design of bucket and nozzle with neddle for single jet Pelton turbine is presented. Bucket dimensions must between maximum and minimum value with respect to jet diameter. The jet diameter is 0.053 m. Notch width of the bucket must be larger than the diameter of jet. If the notch width is smaller than the diameter of jet, some of the incoming water would not strike the next bucket. Besides, all of the hydraulic energy cannot be obtained in this condition and many losses can be occurred. It is important that the jet is always completely intercepted by the buckets so that the volumetric efficiency of the turbine very closes to unity. The angle made by the relative velocity with the direction of motion of vane at outlet, is less than 90 degree and the velocity of whirl is negative. In Pelton turbine, nozzle is also one of the main parts because the available fluid energy is converted into kinetic energy by the nozzle. In this study, single jet nozzle is being used because many nozzle turbine interfered by the big bend of channels to bring the collector. In nozzle design, the calculated result of nozzle outlet diameter must be within the range between 1.2d 0 and
Initially gas phase simulations have been performed to test the performance of the air amplifier under different working conditions. As far as the design of the air amplifier is concerned, two designs are tested based on the gas phase simulations. The first design has a straight rear section of the nozzle (no divergent section) and the second design has a diverging rear section of the nozzle. For each of these designs the performance was tested by varying different operational conditions like, plenum pressures, plenum gaps and a fixed Mach number boundary condition at the mass spectrometer inlet. After studying the results from the gas phase simulations, it was concluded that the diverging nozzle design performs better than the straight nozzle design. To validate the results from the simulations, pressure profiles along the centerline of the nozzle, from experiments and simulations, are compared (see Fig. 4.19). Two turbulence models, Menter SST and Menter BSL are used in these simulations. It was observed that the results from simulations where Menter BSL turbulence model has been used match well with the results from the experiments. For all subsequent simulations, Menter BSL turbulence model has been used to model the turbulence effects.
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mixed fluids blended in a nozzle specifically designed for this purpose and it shall be released into the cutting zone by air-liquid mixture (aerosols). By this technique is also achieved savings of working fluids, being able to achieve their optimization in order to use a minimal amount of the coolant . This paper aims at an analysis the way in which a fluid flows through a small dimensions convergent nozzle. That nozzle combines two working fluids, one gas (air) and another liquid (water). Nozzle type chosen is a common type with a high degree of processing and low price cost. That fluid flow study is needed to understand the occurring phenomena and ways to improve cooling by accurately directing of the fluid flow by using a minimal quantity of lubricant to achieve cooling of the processed area.
Finally, draw the indicator - factor diagram as shown in Figure 3 and Figure 4. As can be seen from Figure 3, A factor (nozzle throat diameter) has the greatest influence on the maximum arc temperature T. The smaller the nozzle throat diameter is, the lower the maximum arc temperature is. The influence of factor B (expansion chamber diameter) and factor C (cylinder diameter) on maximum arc temperature is relatively small. Therefore, considering the index of maximum arc temperature, A1B1C3 is the best combination. It can be seen from the Figure 4 that the A factor (nozzle throat diameter) has the greatest effect on the nozzle throat mass flow G at current zero time, followed by the factor B (expansion chamber diameter) and the factor C (cylinder diameter). Therefore, A1B3C3 is the best combination considering the nozzle throat mass flow.
Electrospun nanofibrous filter media have attracted considerable attention in the last decade. The present study aimed to develop the electrospun PAN (polyacrylonitrile) filter media through experimental investigations for application in high-performance air filters. For this purpose, an experimental design was proposed to assess the effect of electrospinning process conditions including solution concentration, electric voltage and nozzle- collector distance on the structural properties of filter media including the fiber diameter, percent of porosity and bead number. Optimization of electrospinning parameters was conducted through the response surface methodology (RSM) to obtain the desired values for fibrous media variables. The morphology of the mats (including bead number and fiber diameter) were studied using SEM images through, Microstructure Measurement image analyzer. The porosity was determined using image analysis algorithms by MATLAB. The findings indicated that the concentration is the most influencing factor on fiber diameter (r= 0.73, P<0.05) and bead number (r=-0.51, P>0.05), so that the lower concentrations led to lower fiber diameter and more bead number. Among the electrospinning parameters, the highest correlation coefficient was achieved between porosity of PAN media and applied voltage (r=0.39, P>0.05). There was a negative relationship between fiber diameter and both percent of porosity (r=-23; P>0.05) and bead number(r=-0.53; P<0.05). Thus, media with the lower fiber diameter had the higher porosity and more bead number. Since the fibers diameter, bead number and porosity can have different effects on the quality factor of filters, the well-considered selection of electrospinning conditions can be of great importance for obtaining the arbitrary values of filter characteristics.
These atomisers operated at a number of liquid and air injection pressure. Table 3.2 shows result for three different types of two-fluid fine nozzle. It also shows that the experiment with different atomiser on two fluids needs different input pressure from compressed air. Therefore, the bigger pressure input the smaller drop size distribution will atomised. Table 3.3 shows the effect varying three different parameters: atomiser design, liquid injection and flow rate. The lower flow rate for water and gas can only run under low pressure. Low flow rate with low pressure produced big droplet size. Different atomiser design with different flow rate and pressure give different drop size distribution.
Bogdan-Alexandru Belega et-al  said that the Nozzle is a device designed to control the rate of flow, speed, direction, mass, shape, and/or the pressure of the stream that exhaust from them. Nozzles come in a variety of shapes and sizes depending on the mission of the rocket, this is very important for the understanding of the performance characteristics of rocket. By the proper geometrical design of the nozzle, the exhaust of the propellant gases will be regulated in such a way that maximum effective rocket velocity can be reached. Convergent divergent nozzle is the most commonly used nozzle since in using it the propellant can be heated in combustion chamber. After getting heated the propellant first converges at the throat of the nozzle and then expands under constant temperature in the divergent part. In the present paper, flow through the convergent divergent nozzle study is carried out by using a finite volume rewarding code, FLUENT 6.3. The nozzle geometry modeling and mesh generation has been done using GAMBIT 2.4 Software. Computational results are in good acceptance with the experimental results taken from the literature.
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The gas in the analysis is considered to be an ideal gas, which obeys the ideal gas law P = ρRT. The relation suggests that static pressure is directly proportional to the static temperature. As the static pressure decreases along the nozzle exit, so should the static temperature do, being a directly proportional quantity. This can be clearly seen in the above figure. The static temperature change is more sensitive to the change in Mach number than the velocity. It decreases along the downstream of nozzle; however, the total temperature remains constant as the process is adiabatic.
3.3 Effect of Layer Height on mechanical properties The layer height was varied from 0.08 to 0.4 keeping other parameters constant and it was found that tensile strength decreases with increase in layer height while impact and flexural strength along with surface roughness increases with increase in layer height. The tensile strength of the fabricated part decreases with increase in layer height. Less number of layers means less adhesion and less accuracy of the printed part resulting in decrease in tensile strength. There is a considerable increase in impact and flexural strength since the thickness of the layers will be more and hence these layers will act as a whole rather than providing adhesion. Hence the impaci strength and flexural strength will increase. The material is extruded from the nozzle in a cylindrical manner and hence higher layer height means that two cylindrical shaped materials having higher radius are stacked up one above the other and increases the step like effect, eventually increasing the surface roughness.
The paper describes a Diesel fuel injection process. Computer simulation was carried out together with measurement of the Common Rail accumulator fuel-injection system. The computer simula- tion enables the observation of the phenomena from rail pressure, being the input data for injec- tion parameters calculations, to the injection rate. By means of computer simulation, the pressure values in specific sections of the injection nozzle may be computed, the needle lift, injection rate, total injected fuel, time lag from injector current to first evidence of injection process and other time-lags between various phases of the injection process. The injection rate provides input data for spray computer simulation. Measurements of injection and combustion were carried out within a transparent research engine. This engine is a single-cylinder transparent engine based on the AUDI V6 engine, equipped with a Bosch Common Rail Injection System. The comparison between the computed and measured injection parameters showed good matching.
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efficiencies, TEG still avoid additional complex thermodynamic cycles, corresponding installations and their handling for the jet engine system. This principally corresponds to an easier implementation and lower maintenance effort compared to other emerging heat engine technologies (e.g. Organic Rankine Cycle). However, an increased areal coverage by TEG to maximize the efficiency and power output is still difficult especially on hot engines sections (high and low pressure turbine, combustion chamber) due to the typical configuration of jet engines, which offers only a limited installation space. Thus, the installation of the TEG between the hot core stream and the cool bypass flow was investigated in detail for an application at the engine nozzle. While this implementation is certainly subjected to less design constrains it poses the drawback of lower temperature differentials applicable for the TEG.
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CNC-drilling machine X6 is better than that machined by pneumatic bench drilling machine or high frequency and speed bench drilling machine, the flow coefficient can reach about 0.6. The size of the flow value and flow coefficient of the injector nozzle are directly influence the key performance indicators of the diesel engine, such as the power, specific fuel consumption, emission, and so on. Applying liquid extrusion grinding technique can decrease the surface roughness, reduce the fuel injection resistance and increase the flow coefficient of the nozzle spray holes. At present, the high-level engine requires the flow coefficient of the injector nozzle to reach above 0.8 [18, 19], in order to improve the flow coefficient further more, the liquid extrusion grinding in spray hole of the nozzle is conducted in KYM-2 liquid extrusion grinder, and detected the flow value of the nozzle by using an automatic detecting machine LDM-5 for high-press liquid flow. The images of the nozzle spray holes before and after extrusion grinding are shown in Figure 11, the flow values of the nozzle before and after extrusion grinding are shown in Table 4.
m = Σ : average amount of water (mm, ml).n: the number of water accumulation containers. In practice, it‘s not possible to obtain 100% of uniformity on the irrigated area because nozzles distribute water on a circular area, with overlaps between areas of water distribution. It‘s impossible to have equal water distribution on the areas that are being irrigated (Zoldoske et al., 1994). Kara et al. (2008) reported that by decrease of sprinklers spacing and by increasing of nozzle-working pressure, CUC increased. Sahoo et al. (2008) reported that with decreasing of sprinklers spacing and with increasing of nozzles working pressure, the negative effect of wind speed on CUC decreased. Maroufpoor et al. (2010) reported that the application of various coefficients of uniformity depends on the field conditions and as any specific coefficient of uniformity is suitable only for specific field conditions. Makki et al. (2011) reported that the twin nozzle brass sprinkler gave significantly better efficiency in comparison with twin nozzle plastic sprinkler and single nozzle plastic sprinkler. Stambouli et al. (2014) reported that sprinkler model has an important effect on the radial water distribution, even under similar operational conditions. Farzad-Manesh et al. (2011) reported that with increasing of riser height from 90 cm to 15 cm, CUC increased. Younesi et al. (2015) reported that using from many sprinklers on the laterals, caused decrease in CUC and is not economical in permanent sprinkler irrigation system. Yacoubi et al. (2012) reported that wind speed and relative humidity were the most important factor in wind and evaporation losses. The main objective in this research was evaluation of Christiansen’s uniformity coefficient in different conditions of wind speed, nozzle diameters, nozzle-working pressure, layout and sprinklers spacing.