Journal articles: 'Uneven flow distribution'

1

Cho, Hyungtae, Junghwan Kim, Chanho Park, Kwanghee Lee, Myungjun Kim, and Il Moon. "Uneven distribution of particle flow in RFCC reactor riser." Powder Technology 312 (May 2017): 113–23. http://dx.doi.org/10.1016/j.powtec.2017.01.025.

Full text

APA, Harvard, Vancouver, ISO, and other styles

2

Badriev, A. I., and S. M. Vlasov. "Estimation of the distribution of water and air flows in a laboratory cooling tower." Power engineering: research, equipment, technology 21, no. 5 (December 17, 2019): 71–78. http://dx.doi.org/10.30724/1998-9903-2019-21-5-71-78.

Full text

Abstract:

A decrease in the efficiency of the tower cooling tower of the TPP was found, especially in the summer. It has been proposed that one of the reasons for the decrease in productivity may be uneven distribution of flows. Experimental studies of the density distribution of irrigation water and air flow of a tower cooling tower have been carried out. The actual operating characteristics of the cooling device are obtained taking into account the uneven flow. Due to the influence of internal and external factors on the performance of the full- scale tower, it was decided to check the performance at its laboratory installation. An experimental analysis of the distribution of irrigation density and air velocity was performed on a laboratory model of a cooling tower. The experimental characteristics of the full-scale tower cooling tower in a laboratory installation were confirmed: the dependence of air speed, temperature drop of water and cooling power on the distribution of irrigation density. Taking into account the uneven flow of water and air is an important task in the design and operation of tower towers. The problem of rational distribution of irrigation density and air flow in a tower cooling tower is formulated.

APA, Harvard, Vancouver, ISO, and other styles

3

Ji, Shou Wen, Lin Shuai Wang, and Kai Ding. "Study on Freight Traffic Flow of Port." Applied Mechanics and Materials 178-181 (May 2012): 1773–77. http://dx.doi.org/10.4028/www.scientific.net/amm.178-181.1773.

Full text

Abstract:

There are clear industrial characteristics of freight traffic flow in port. According to the round distribution method, the uneven distribution of time, functional orientation of road network and properties of mixed flow road are analyzed with the example of Lianyungang.

APA, Harvard, Vancouver, ISO, and other styles

4

Huang, Yanchen, and Xinbo Huang. "Flow field distribution around insulator and contamination uneven characteristic of insulator." IET Science, Measurement & Technology 14, no. 10 (December 20, 2020): 1088–97. http://dx.doi.org/10.1049/iet-smt.2020.0277.

Full text

APA, Harvard, Vancouver, ISO, and other styles

5

Xia, G. L., G. H. Su, and M. J. Peng. "Analysis of flow distribution in plate-type core affected by uneven inlet temperature distribution." Annals of Nuclear Energy 92 (June 2016): 333–44. http://dx.doi.org/10.1016/j.anucene.2016.01.044.

Full text

APA, Harvard, Vancouver, ISO, and other styles

6

Qian, Dongsheng, Chengfei Ma, and Feng Wang. "The Effect of Flow Lines on the Mechanical Properties in Hot-Rolled Bearing Steel." Metals 11, no. 3 (March 10, 2021): 456. http://dx.doi.org/10.3390/met11030456.

Full text

Abstract:

Hot rolling is an essential process for the shape-forming of bearing steel. It plays a significant role in the formation and distribution of flow lines. In this work, the effect of flow lines is investigated by analyzing the microstructure and mechanical anisotropy of hot-rolled bearing steel. It was found that carbides rich with Cr and Mn elements are distributed unevenly along the flow-line direction of the hot-rolled bearing steel. Moreover, the mechanical characterization indicates that ultimate tensile strength and yield strength do not have any significant difference in two directions. Nevertheless, an ultrahigh section shrinkage of 57.51% is obtained in the 0° sample that has parallel flow lines, while 90° sample shows poor section shrinkage. The uneven distributed carbides will affect the direction and speed of crack propagation during tensile deformation. Therefore, the 0° and 90° samples exhibit great difference in plastic property. Meanwhile, after tensile deformation, a delaminated texture is observed in the flow lines, which may be caused by different degrees of deformation of grains due to the uneven distribution of carbides. The results of this work may provide guidance for controlling and optimizing flow lines in the manufacturing of bearing rings.

APA, Harvard, Vancouver, ISO, and other styles

7

Fleischer, F., C. Koerner, and J. Mann. "Flow Guiding and Distributing Devices on the Exhaust Side of Stationary Gas Turbines." Journal of Engineering for Gas Turbines and Power 112, no. 1 (January 1, 1990): 80–85. http://dx.doi.org/10.1115/1.2906481.

Full text

Abstract:

Following repeated cases of damage caused to exhaust silencers located directly beyond gas turbine diffusers, this paper reports on investigations carried out to determine possible remedies. In all instances, an uneven exhaust gas flow distribution was found. The company’s innovative approach to the problem involved constructing a scale model of a complete gas turbine exhaust system and using it for flow simulation purposes. It was established for the first time that, subject to certain conditions, the results of tests conducted on a model can be applied to the actual turbine exhaust system. It is shown that when an unfavorable duct arrangement might produce an uneven exhaust flow, scale models are useful in the development of suitable flow-distributing devices.

APA, Harvard, Vancouver, ISO, and other styles

8

Zhou, Qi, and Yong Pang. "Calculation of Water Environmental Capacity of Tidal Reaches in Estuarine Areas on the Basis of Uneven Coefficient." Applied Mechanics and Materials 507 (January 2014): 790–97. http://dx.doi.org/10.4028/www.scientific.net/amm.507.790.

Full text

Abstract:

In view of the reciprocating flow of the tidal reaches in estuarine areas and uneven horizontal distribution in the process of pollutants transferring, this thesis proposes a calculation method for the water environmental capacity on the basis of reciprocating flow model and uneven coefficient method. Taking North Channel, downstream of the Min River, as an example, a two-dimensional unstable-state model of water flow-quality is established. According to its hydrologic features and the date measured, flow field and concentration field of this river section are simulated, and meanwhile, response relation curve of the discharge capacity of those general pollutant sources in relation to length of pollution zones, at moments of maximum flood tide and maximum tide ebb, is built. Besides, North Channel is divided into two studied sections whose uneven distribution coefficients at the above mentioned two moments are calculated respectively. Considering the reliability, uneven coefficients at floodtide and tide ebb are replaced by those at the moment of maximum flood tide and maximum tide ebb, and the uneven coefficient method is adopted, on the basis of reciprocating flow model, to calculate the water environmental capacity of North Channel. The findings show that, by adopting the two-dimensional unstable-state model of water flow-quality, values of both the flow field and concentration field in this river section thus calculated, are approximate to the values measured. Chooses 90% confidence surface flow and take neap as sample, the water environmental capacity of CODMn in North Channel is 16716.8t/a.This method, together with the reciprocating flow model and uneven coefficient method, reflects the influence of reciprocating flow and complex pollution migration and diffusion, under the tidal action, on the water environmental capacity of tidal reaches in estuarine areas.

APA, Harvard, Vancouver, ISO, and other styles

9

Qing, L., M. R. Bilad, Guofei Sun, Juhana Jaafar, and Anthony G. Fane. "Flow uneven-distribution and its impact on performances of forward osmosis module." Journal of Water Process Engineering 33 (February 2020): 101014. http://dx.doi.org/10.1016/j.jwpe.2019.101014.

Full text

APA, Harvard, Vancouver, ISO, and other styles

10

Fu, Hai Ming, and You Jun Zhao. "Experimental Study on Flow Field Characteristic of Bag Filter." Advanced Materials Research 508 (April 2012): 254–58. http://dx.doi.org/10.4028/www.scientific.net/amr.508.254.

Full text

Abstract:

In order to select best filtration velocity of bag filters and to improve gas flow distribution, to increase collection efficiency and to reduce operation resistance, gas flow distribution was tested by using hot-wire anemometer, CFD simulation was made and basic accordant result was obtained by comparing simulation result with experimental result. Test results and analysis showed that: Uneven distribution of flow field was caused by jet flow, critical filtration velocity exited in flow field distribution. Improving measure of flow field and optimize method of bag filter structure was putted out.

APA, Harvard, Vancouver, ISO, and other styles

11

Tingaud, Florian, Sébastien Ferrouillat, Stéphane Colasson, Odin Bulliard-Sauret, and André Bontemps. "Improvement of Two-Phase Flow Distribution in Compact Heat Exchangers by Using Ultrasound." Applied Mechanics and Materials 392 (September 2013): 521–25. http://dx.doi.org/10.4028/www.scientific.net/amm.392.521.

Full text

Abstract:

In this communication we present a new active method to modify two-phase flow distribution in a heat exchanger, when it is in operation, by using ultrasound generators which can be activated when necessary. An experimental study has been carried out to validate the concept and to evaluate the effects of ultrasound on the flow distribution. An experimental test rig was built to measure the flow distribution in realistic manifold and parallel channel geometry. The test section is composed of a manifold feeding 10 channels with air-water mixture. In front of each channel a piezoelectric generator is placed to emit ultrasonic waves which can interact with liquid flows. Comparison was made between two-phase flows with and without ultrasound. It was demonstrated that, in most cases, uneven distribution was improved by using ultrasound.

APA, Harvard, Vancouver, ISO, and other styles

12

Li, Da, Zhonghua Yang, Zhaohua Sun, Wenxin Huai, and Jianhua Liu. "Theoretical Model of Suspended Sediment Concentration in a Flow with Submerged Vegetation." Water 10, no. 11 (November 14, 2018): 1656. http://dx.doi.org/10.3390/w10111656.

Full text

Abstract:

Vegetation in natural river interacts with river flow and sediment transport. This paper proposes a two-layer theoretical model based on diffusion theory for predicting the vertical distribution of suspended sediment concentration in a flow with submerged vegetation. The suspended sediment concentration distribution formula is derived based on the sediment and momentum diffusion coefficients through the inverse of turbulent Schmidt number ( S c t ) or the parameter η which is defined by the ratio of sediment diffusion coefficient to momentum diffusion coefficient. The predicted profile of suspended sediment concentration moderately agrees with the experimental data. Sensitivity analyses are performed to elucidate how the vertical distribution profile responds to different canopy densities, hydraulic conditions and turbulent Schmidt number. Dense vegetation renders the vertical distribution profile uneven and captures sediment particles into the vegetation layer. For a given canopy density, the vertical distribution profile is affected by the Rouse number, which determines the uniformity of the sediment on the vertical line. A high Rouse number corresponds to an uneven vertical distribution profile.

APA, Harvard, Vancouver, ISO, and other styles

13

Zhang, Shiwei, and Jun Liu. "Distribution of Vapor Pressure in the Vacuum Freeze-Drying Equipment." Mathematical Problems in Engineering 2012 (2012): 1–10. http://dx.doi.org/10.1155/2012/921254.

Full text

Abstract:

In the big vacuum freeze-drying equipment, the drying rate of materials is uneven at different positions. This phenomenon can be explained by the uneven distribution of vapor pressure in chamber during the freeze-drying process. In this paper, a mathematical model is developed to describe the vapor flow in the passageways either between material plates and in the channel between plate groups. The distribution of vapor pressure along flow passageway is given. Two characteristic factors of passageways are defined to express the effects of structural and process parameters on vapor pressure distribution. The affecting factors and their actions are quantitatively discussed in detail. Two examples are calculated and analyzed. The analysis method and the conclusions are useful to estimate the difference of material drying rate at different parts in equipment and to direct the choice of structural and process parameters.

APA, Harvard, Vancouver, ISO, and other styles

14

Gao, Ya Nan, Jun Nan Yi, Rui Cun Zhao, Li Fen Chen, and Xu Min Wu. "Hydraulic Performance Optimization on Inlet-Outlet of Pumped Storage Plant." Applied Mechanics and Materials 405-408 (September 2013): 491–94. http://dx.doi.org/10.4028/www.scientific.net/amm.405-408.491.

Full text

Abstract:

This paper, using 3-D numerical simulation and the hydraulic model tests, presents an analysis on hydraulic performance of pumped storage plant inlet/outlet. It discusses the uneven flow coefficient, coefficient of orifice flow distribution and head loss coefficient of inlet/outlet in different sizes. The optimized size has a uniform flow distribution, with less to produce unwanted eddies.

APA, Harvard, Vancouver, ISO, and other styles

15

Bazaras, Jonas, Janina Jablonskytė, and Eglė Jotautienė. "INTERDEPENDENCE OF NOISE AND TRAFFIC FLOW." TRANSPORT 23, no. 1 (March 31, 2008): 67–72. http://dx.doi.org/10.3846/1648-4142.2008.23.67-72.

Full text

Abstract:

Traffic flows in cities, especially in city centres, are intensive and uneven, moreover, registered noise levels exceed allowable limits. Noise levels have been measured at K. Mindaugo ave. and Birštono street crossing in Kaunas and data of automated traffic flow registration equipment have been used. A constant reduction of noise level from the beginning till the end of the green light has been identified ‐ “hot starts” generated noise dominates. To make estimates of noise and traffic flow interdependency, mathematical statistical models have been applied. Parameter distribution patterns have been analysed, prediction models have been composed.

APA, Harvard, Vancouver, ISO, and other styles

16

McGarry, M., and L. Grega. "Effects of Inlet Mass Flow Distribution and Magnitude on Reactant Distribution for PEM Fuel Cells." Journal of Fuel Cell Science and Technology 3, no. 1 (July 20, 2005): 45–50. http://dx.doi.org/10.1115/1.2134736.

Full text

Abstract:

The mass flow distribution and local flow structures that lead to areas of reactant starvation are explored for a small power large active area PEM fuel cell. A numerical model was created to examine the flow distribution for three different inlet profiles; blunt, partially developed, and fully developed. The different inlet profiles represent the various distances between the blower and the inlet to the fuel cell and the state of flow development. The partially and fully developed inlet profiles were found to have the largest percentage of cells that are deficient, 20% at a flow rate of 6.05 g/s. Three different inlet mass flow rates (stoichs) were also examined for each inlet profile. The largest percent of cells deficient in reactants is 27% and occurs at the highest flow rate of 9.1 g/s (3 stoichs) for the partially and fully developed turbulent profiles. In addition to the uneven flow distribution, flow separation occurs in the front four channels for the blunt inlet profile at all flow rates examined. These areas of flow separation lead to localized reactant deficient areas within a channel.

APA, Harvard, Vancouver, ISO, and other styles

17

Li, J. H., Z. J. Yu, D. P. Jiang, and W. Chen. "Stress and Strain Characteristics of Aluminum Equal Channel Angular Pressing." Applied Mechanics and Materials 440 (October 2013): 92–96. http://dx.doi.org/10.4028/www.scientific.net/amm.440.92.

Full text

Abstract:

To investigate the stress and strain distribution characteristics of equal channel angular pressing (ECAP), rigid-plastic finite element was used to simulate the aluminum ECAP processing. The simulation results showed that equivalent stress distribution of the sample was uneven, and severe stress concentration was at the channel corner. Equivalent strain distribution of the sample was also uneven, and the deformed sample can be roughly divided as three deformation regions: the front, the middle and the end. At the region of front, the plasctic deformation was extremely uneven and the gradient value of equivalent strain was relatively large, at the region of middle, the plasctic deformation was stable and uniform, at the region of end, there existed material reverse flow the sample contacted with the plunger and bearing heavy three-dimensional compressive stress.

APA, Harvard, Vancouver, ISO, and other styles

18

Patsch, Marek, and Peter Pilát. "Simulation of Combustion Air Flow in the Gasification Biomass Boiler." MATEC Web of Conferences 168 (2018): 02015. http://dx.doi.org/10.1051/matecconf/201816802015.

Full text

Abstract:

The article deals with the optimization of biomass combustion in a small heat source by means of an optimal distribution of combustion air. The uneven distribution of combustion air has been observed in certification tests and in real operation of used heat source and it has an influence on uneven combustion of biomass in the gasification chamber, on increase emissions and combustion losses. At this stage of the research, optimization of the combustion air distribution is performed by CFD simulations, which will be later verified by PIV measuring of the velocity fields in gasification and combustion chambers of the experimental heat source. CFD simulations and subsequent PIV measurements on the experimental device are realized without real combustion, only the air flow in the empty gasification chamber and in the combustion chamber is investigated. This approach has been chosen to simplify calculations and experiments, and on the assumption that when the combustion air distribution is optimal in empty chambers, it will be optimal even during real combustion. The primary air flow in the gasification chamber is in real operation affected by the size and shape of the inserted biomass and its placement in chamber and this effect is accidental and difficult to verifiable.

APA, Harvard, Vancouver, ISO, and other styles

19

Mitrović, Darko, and Andrej Novak. "Two-Phase Nonturbulent Flow with Applications." Mathematical Problems in Engineering 2015 (2015): 1–8. http://dx.doi.org/10.1155/2015/439704.

Full text

Abstract:

We model dynamics of two almost immiscible fluids of different densities using the Stokes equations with the Dirac distribution representing the sink or source point. The equations are solved by regularizing the Dirac distribution and then using an iterative procedure based on the finite element method. Results have potential applications in water pollution problems and we present two relevant situations. In the first one, we simulate extraction of a light liquid trapped at the bottom of a pond/lake and, after being disturbed, it rises toward the surface. In the second case, we simulate heavy liquid leaking from a source and slowly dropping on an uneven bottom.

APA, Harvard, Vancouver, ISO, and other styles

20

Golovnin, Oleg, and Anastasia Stolbova. "Wavelet Analysis as a Tool for Studying the Road Traffic Characteristics in the Context of Intelligent Transport Systems with Incomplete Data." SPIIRAS Proceedings 18, no. 2 (April 12, 2019): 326–53. http://dx.doi.org/10.15622/sp.18.2.326-353.

Full text

Abstract:

A frequent problem of traffic flow characteristics acquisition is data loss, which leads to uneven time series analysis. An effective approach to uneven data analysis is the spectral analysis, which requires obtaining process with a constant sampling interval, for example, by restoring missing data, which leads to the appearance of dating error. Thus, the main purpose of this study is to develop a method and software for wavelet analysis of traffic flow characteristics without restoring the missing data. To analyze and interpret non-stationary uneven time series obtained from traffic monitoring systems, we propose the wavelet transformation method with adjustment of the sampling intervals, which results in a time-frequency domain with a constant sampling interval. Wavelet analysis is applied to the macroscopic traffic flow characteristics. We developed the software for traffic flow wavelet analysis on the "ITSGIS" intelligent transport geo-information framework using the attribute-oriented approach. Wavelet analysis of traffic flows characteristics using Morlet wavelets was accomplished for data analysis of the city of Aarhus, Denmark. Wavelet spectra and scalograms were constructed and analyzed, general dependencies in the frequency distribution of extremes, and differences in spectral power were revealed. The developed software is being experimentally tested in solving practical problems of municipalities and road agencies in Russia.

APA, Harvard, Vancouver, ISO, and other styles

21

Zhou, San Pin. "Study on Wall-Flow of a New Type of Efficient Uniform-Flow Packed Equipment." Advanced Materials Research 791-793 (September 2013): 786–89. http://dx.doi.org/10.4028/www.scientific.net/amr.791-793.786.

Full text

Abstract:

In order to deal with the wall flow effect and the scaling effect because of uneven distribution of fluid overall that commonly exist in packed tower, a new type efficient symmetrical-flow packed equipment was developed. In the same condition, the symmetrical-flow packed equipment was studied comparatively with the common packed equipment by experiments and numerical simulation, and the results such as pressure drop, wall-flow contours and velocity distribution were given. The study results show that the pressure drop of two kinds of packed tower have no significant differences , wall flow is significantly reduced by about 31%, gas-liquid velocity uniformly distribute compared with ordinary packing. The result demonstrate that the symmetrical-flow packed equipment has good effect tin improving the uniform distribution of the macroscopic flowing of fluid, the wall flow effect of the symmetrical-flow packed equipment can be effectively reduced, and the scaling effect eliminated. So the mass transfer efficiency of the packed tower is improved.

APA, Harvard, Vancouver, ISO, and other styles

22

Bytčanková, Lucia, Ján Rumann, and Peter Dušička. "Analyzing the impact of intake structure on the flow at low pressure SHPP." Pollack Periodica 16, no. 1 (March 25, 2021): 114–19. http://dx.doi.org/10.1556/606.2020.00149.

Full text

Abstract:

AbstractThe structural parts of intake structures directly affect the flow velocity distribution in the turbine intake of small hydropower plants, where inhomogeneous flow leads to uneven load of the turbine units causing operational problems. A 2D numerical flow modeling was used for investigations of the flow in an intake structure of a low-head small hydropower plant. The effects of shape changes of the intake structure on the flow velocity distribution in the turbine intakes were investigated and assessed proving significant effect of the shapes of the intake structure on the flow homogeneity in turbine intakes.

APA, Harvard, Vancouver, ISO, and other styles

23

Ramasamy, Govindarasu, R. Kavitha, M. Nambiraj, R. Praveen Kumaar, and N. N. Harish Kumar. "Analysis on Geometry of Fluid Flow Manifold in Direct Methanol Fuel Cell." European Journal of Engineering Research and Science 5, no. 8 (August 5, 2020): 822–27. http://dx.doi.org/10.24018/ejers.2020.5.8.1851.

Full text

Abstract:

Fuel cells are the devices that convert chemical energy into electrical energy through an electrochemical reaction. Direct Methanol Fuel cell (DMFC) is a proton exchange membrane fuel cells in which methanol is used as fuel. Its high energy density makes it suitable for fuel cells. Even though carbon dioxide is produced, there is no production of sulfur or nitrogen oxides. The problems usually occurred while working with DMFC are methanol crossover, condensation of methanol, water management and carbon dioxide release. In that the uneven flow distribution, accumulation of carbon dioxide bubbles in the fuel cell are the major issues in DMFC. To prevent these issues, this work focuses on the theoretical and experimental studies on development of fuel cells with special importance to geometry of the manifold. This paper provides the optimal solution for preventing uneven flow distribution that is the usage of squoval shaped manifold which is the combination of both square and circle. Performance of DMFC with squoval shape manifold is evaluated experimentally and is compared with square shape manifold and rectangle shape manifold geometry design.

APA, Harvard, Vancouver, ISO, and other styles

24

HAYASHI, Daisuke, Hiroshi IWAI, Motohiro SAITO, and Hideo YOSHIDA. "G101 Uneven flow distribution in a stack of planer SOFC caused by temperature non-uniformity." Proceedings of the National Symposium on Power and Energy Systems 2011.16 (2011): 155–56. http://dx.doi.org/10.1299/jsmepes.2011.16.155.

Full text

APA, Harvard, Vancouver, ISO, and other styles

25

Li, Ting, Yongsheng Tan, Faraj A. Ahmad, and Jun Zhao. "Experimental Study of Sand Distribution among Perforation Clusters in Horizontal Wellbore of Shale Gas Reservoir." Journal of Chemistry 2020 (July 25, 2020): 1–7. http://dx.doi.org/10.1155/2020/2704685.

Full text

Abstract:

Multistage horizontal fracturing is the key technique in developing shale gas reservoirs. In each stage, several perforation clusters will be placed to create complex fractures, and the parameters of perforation clusters are almost the same, so the production from each perforation cluster should be similar. However, in fact, production from each perforation cluster is different vastly. If the characteristics of the shale gas reservoir where the horizontal wellbore oriented through are similar, the cause that resulted in production difference may be uneven proppant distribution among perforation clusters. In order to investigate proppant distribution through perforation clusters, the theory about proppant settling along horizontal lateral is analyzed, which can provide a proper pumping rate for future experiments. Then, an experimental model to simulate horizontal lateral and perforated clusters is designed. Fresh water was pumped to transport proppant flowing into different clusters, the volume of water and proppant through each cluster was qualified. Some parameters, such as proppant concentration, sizes, flow rate, and perforation parameters, are changed in lab tests; the simulation results will be helpful in understanding the phenomenon of uneven proppant distribution in perforation clusters. There are some conclusions from the experimental results. First, proppant settling at different positions along horizontal lateral is different when the slurry is mixed by proppant and water is pumped at different rates. Meanwhile, proppants concentration also has an influence on proppants settling. The settling of proppants will impact proppants distribution among perforation clusters. Second, at a low pumping rate, uneven proppants distribution was observed mostly. When the pumping rate was increased, the phenomenon of uneven proppants distribution was decreasing. Thus, the pumping rate is the main influential factor. Third, uneven proppants distribution can be improved or even avoided by adjusting perforation parameters, such as perforation numbers and diameter.

APA, Harvard, Vancouver, ISO, and other styles

26

Yang, Zhi Qiang, and C. J. Wu. "The Influence of Non-Uniform Impeller on the Cross Flow Fan Noise." Key Engineering Materials 693 (May 2016): 251–56. http://dx.doi.org/10.4028/www.scientific.net/kem.693.251.

Full text

Abstract:

The aerodynamic noise of a cross flow fan with uneven blade spacing in room air-conditioner was simulated by computational aerodynamic acoustics (CAA) method. It is detailed to analyze the vorticity distribution of the flow field and the power spectral density of measured points’ pressure fluctuations, and the results demonstrate the non-uniform impeller used in this paper can significantly improve internal flow characteristics. Thus the broadband noise got reduced.

APA, Harvard, Vancouver, ISO, and other styles

27

Hopmann, Christian, Nafi Yesildag, and Malte Schön. "Thermal influences in the star-pre-distributor of a spiral mandrel die." Journal of Polymer Engineering 37, no. 8 (October 26, 2017): 837–44. http://dx.doi.org/10.1515/polyeng-2016-0405.

Full text

Abstract:

AbstractThe main criterion in the design of extrusion dies is to ensure a uniform velocity distribution of the plastics melt at the die outlet. In the case of spiral mandrel dies, the flow balance can be influenced negatively by thermal effects which are especially dominant in the pre-distributor. In previous works, it was shown that thermal inhomogeneity in a 2n-pre-distributor leads to an uneven melt distribution at the end of the pre-distributor. In the present study, the temperature influence on the melt distribution in a star-pre-distributor is investigated for three different polyethylenes with the help of flow simulations in Polyflow (Ansys). The simulation model depicts the whole pre-distributor and takes both the shear heating in the melt and the heat conduction in the pre-distributor into account. The simulative analysis shows that the dissipative shear heating leads to an uneven throughput distribution in the star-pre-distributor. In order to compensate this effect, in the next step of the simulations, heating cartridges are applied to the pre-distributor. In this way a significant homogenization of the pre-distribution can be achieved.

APA, Harvard, Vancouver, ISO, and other styles

28

Li, Ling Ling, Guang Pu Xu, Zhen Dong Su, and Yong Ling Kang. "Flow Field Analysis of Valve Plate for Hot Blast Valve." Advanced Materials Research 628 (December 2012): 523–27. http://dx.doi.org/10.4028/www.scientific.net/amr.628.523.

Full text

Abstract:

The valve plate of the hot blast valve is to rely on itself spiral waterway to cool. In the course of actual use, there is uneven actuality that it is cold and hot for the Valve plate of the hot blast valve. In this article, by means of COSMOSFloworks software, based on classic formula for convective heat transfer of heat transfer, we do flow field analysis for the waterway of the valve plate of DN1800 hot blast valve for certain Heavy Industry Group of our country. And analytical result indicates: Uneven distribution of water velocity in the valve plate is an important reason for causing unequal heat exchange of the valve plate and local thermal shock. In order to improve cooling uniformity, the central flow state of the type valve Plate should be altered and water cooling structure of inner water ring edge should be widen, finally the increase of the life of the valve plate can be reached.

APA, Harvard, Vancouver, ISO, and other styles

29

Ignatenko, Evgenii, and Yuliya Bryanskaya. "Velocity distribution in a turbulent flow." E3S Web of Conferences 263 (2021): 04047. http://dx.doi.org/10.1051/e3sconf/202126304047.

Full text

Abstract:

The article considers the issue of velocity distribution in a turbulent flow. The logarithmic velocity profile obtained on the basis of semiempirical theory of turbulence by L. Prandtl is given. A comparison of the calculations of the velocity distribution for various dependencies with the measurement data is performed. It is shown that the calculated dependencies show discrepancy with each other and experimental data. The study of the hydraulic characteristics of water flows is required to solve problems of water supply and water disposal, engineering problems of hydraulic construction, regulation of riverbed processes and environmental monitoring of water bodies. The characteristics of the turbulence of a uniform and uneven flow need to be clarified, that will be possible due to the study of the theoretical background of hydraulics and hydrodynamics. Despite the usage of modern computer technologies, the creation of an actual theory of turbulence is still not complete. The separation of the fluid motion into molar and basic motion led to a non-closed system of equations of turbulent motion, that slowed down further progress in the search for a solution for turbulent flow. The most widely used theory is the semi-empirical theory of turbulence by L. Prandtl, based on a phenomenological approach that links turbulence with the characteristics of the averaged flow. The use of modern technology has allowed us to obtain new experimental data that require analysis and generalization. The calculated dependences for the velocity distribution developed on the basis of various phenomenological models, including the well-known logarithmic profiles of L. Prandtl, are compared with the measurement data. The calculations of the velocity distribution for various dependencies are compared with the measurement data. A significant quantitative, and sometimes qualitative, discrepancy of the calculated dependences with each other and with the experimental data was revealed. The discrepancy between the results of calculating the velocity distribution for different dependencies requires an additional critical analysis of the accuracy and reliability of the experimental data of other authors and performing experimental studies under different conditions using a mutually agreed method. The low effectiveness of the considered statistical approaches leads to the need to develop new approaches that represent a combination of some theoretical concepts and experimental data.

APA, Harvard, Vancouver, ISO, and other styles

30

Okabe, Tomonaga, and Kei Urabe. "Monitoring of Filler Distribution in Resin with an Electromagnetic Wave Transmission Line." Advanced Composites Letters 12, no. 2 (March 2003): 096369350301200. http://dx.doi.org/10.1177/096369350301200203.

Full text

Abstract:

The authors previously presented a new method for monitoring resin flow and curing with a high-frequency electromagnetic wave transmission line constructed inside a structure. This method can provide information on discontinuities or distributions by using frequency characteristics or the time-domain response. In this paper, we applied our method for monitoring the defects in resin, such as uneven distribution of reinforcement or filler, voids or contamination, in the manufacturing process. The experimental results demonstrated the possibility of a transmission line as a monitoring tool and showed that the area with defects can be characterized by comparing with results of theoretical calculations.

APA, Harvard, Vancouver, ISO, and other styles

31

Santic, Danica. "Challenges in a population policy toward migrations under the conditions of uneven distribution of population potentials in Serbia." Zbornik Matice srpske za drustvene nauke, no. 167 (2018): 651–62. http://dx.doi.org/10.2298/zmsdn1867651s.

Full text

Abstract:

Population distribution, as one of the key topics in geographical research, reflects the integrity of physical, social, economic and historical factors of certain area. This paper provides an overview of the spatial concentration of population in Serbia at the beginning of XXI century (Censuses 2002 and 2011). The analysis of population distribution and redistribution was performed at different levels of territorial structure of Serbia. The results indicate uneven distribution of population potentials (both in quantitative and qualitative ways) by expanding the area of extremely low and extremely high concentration. However, there remains a need for a broader scientific consideration of migration flows in order to create migration policies. Those policies are of interest to geographers because they represent attempts to manage the flow of people and to alter the geographical pattern of population distribution and characteristics.

APA, Harvard, Vancouver, ISO, and other styles

32

Homer, L. D., P. K. Weathersby, and S. Survanshi. "How countercurrent blood flow and uneven perfusion affect the motion of inert gas." Journal of Applied Physiology 69, no. 1 (July 1, 1990): 162–70. http://dx.doi.org/10.1152/jappl.1990.69.1.162.

Full text

Abstract:

Monte Carlo simulations of the passage of inert gas through muscle tissue reveal that countercurrent gas exchange is more important than heterogeneity of flow in determination of the shape of inert gas washout curves. Semilog plots of inert gas washout are usually curved rather than straight. Two explanations often offered are that countercurrent flow may distort the shape and that uneven perfusion of the tissue gives rise to nonuniform washout. The curvature of the semilog plot may be summarized by the relative dispersion (RD), which is the ratio of the standard deviation of transit times to the mean transit time. For straight semilog plots, RD is 1. Semilog plots of data showing xenon washout from dog tissues are curved and have and RD of approximately 2. We have simulated the transit of gas particles through a vascular bed composed of repeating units of 100 mg of tissue perfused by three small vessels 80 microns in diameter and several levels of branching that direct flow through 190,000 capillaries. Geometric distribution of flow is important. Similar degrees of flow heterogeneity affect the curvature of the washout curve more if regions of heterogeneous flow are widely spaced than if they are close together. Diffusion blunts the effects of heterogeneous flow by mixing particles in high-flow regions with particles in low-flow regions. Because of this mixing, alternating regions of high flow and low flow spaced at intervals of less than 0.5 cm are unlikely explanations for the curved semilog plots.(ABSTRACT TRUNCATED AT 250 WORDS)

APA, Harvard, Vancouver, ISO, and other styles

33

Adari, Matha Prasad, P. Lavanya, P. Hara Gopal, T. Praveen Sagar, and S. Pavani. "Experimental Investigation of Proton Exchange Membrane (PEM) Fuel Cell Using Different Serpentine Flow Channels." Materials Science Forum 969 (August 2019): 461–65. http://dx.doi.org/10.4028/www.scientific.net/msf.969.461.

Full text

Abstract:

Proton exchange membrane fuel cell (PEMFC) system is an advanced power system for the future that is sustainable, clean and environmental friendly. The flow channels present in bipolar plates of a PEMFC are responsible for the effective distribution of the reactant gases. Uneven distribution of the reactants can cause variations in current density, temperature, and water content over the area of a PEMFC, thus reducing the performance of PEMFC. By using Serpentine flow field channel, the performance is increased. Two types of serpentine flow field channels are implemented such as curved serpentine flow field channel and normal serpentine flow field channels. The result shows that curved serpentine flow field channel gives better current density and power density, thus increasing the performance of PEMFC.

APA, Harvard, Vancouver, ISO, and other styles

34

Zhao, Jiu Zhou, and Hong Xiang Jiang. "Solidification of Immiscible Alloys and Convective Effect." Materials Science Forum 783-786 (May 2014): 2231–36. http://dx.doi.org/10.4028/www.scientific.net/msf.783-786.2231.

Full text

Abstract:

A model describing the microstructure formation in a directionally solidified immiscible alloy under the convective effect is presented. The microstructure evolution in a directionally solidified Al-Pb alloy is investigated. It is demonstrated that convective flows have great effects on the solidification of immiscible alloys. A convective flow against the solidification direction causes an increase in the nucleation rate while a convective flow along the solidification direction causes a decrease in the nucleation rate. The convective flows lead to a more uneven distribution of the minority phase droplets in the melt. It causes an increase in the size of the largest minority phase droplets and is against the obtaining of the immiscible alloys with a well dispersed microstructure.

APA, Harvard, Vancouver, ISO, and other styles

35

Guo, Hao, Song Zhou, Majed Shreka, and Yongming Feng. "A Numerical Investigation on the Optimization of Uneven Flow in a Marine De-SOx Scrubber." Processes 8, no. 7 (July 17, 2020): 862. http://dx.doi.org/10.3390/pr8070862.

Full text

Abstract:

According to regulations from the International Maritime Organization (IMO), the sulfur content of vessels must not exceed 0.5% outside the Emission Control Areas (ECAs) starting from 2020. The marine exhaust gas desulfurization (De-SOx) system is the most feasible technology to meet the increasing regulations, but there is always a large swirl at the bottom of the scrubber causing uneven flow past the sprays. Solving this problem by adjusting the spray is a feasible method. The exhaust gas at 485 K and injection liquid at 305 K are simulated to optimize the flow field in a De-SOx scrubber. The results indicated that the flue gas was easily concentrated in the left side area of the scrubber and this part of hot gas could escape from the scrubber. By controlling the nozzles distribution and the nozzles angle, it was possible to reduce the droplets to hit the wall and improve the utilization rate of the washing liquid. The nozzles were arranged up and down in different positions, which reduced the escape amount of exhaust gas in the strong offset area. The new arrangement of nozzles made the flow field distribution inside the scrubber more uniform and increased the gas–liquid reaction time Although the pressure drop under outermost nozzles 45° injection was smaller than the vertical injection, the flow field under 45° injection became more complex and the outlet gas velocity became larger.

APA, Harvard, Vancouver, ISO, and other styles

36

Zong, Quan Li, and Tie Gand Zheng. "Numerical Simulation on Flow Field of Screen Filter for Drip Irrigation in Field." Applied Mechanics and Materials 212-213 (October 2012): 1197–200. http://dx.doi.org/10.4028/www.scientific.net/amm.212-213.1197.

Full text

Abstract:

Based on CFD software Fluent, the flow field of screen filter was simulated numerically，and the results of calculation were analyzed in detailed. The results show that the velocity distribution declines along the radial direction of tank. The flow can be rotated and mixed in tank, and the screen of outlet can be clogged quickly resulting in uneven clogging. The turbulent pressure distribution of filter is not uniformity. In the inlet, the turbulent energy is larger than the second tank. In the inlet of second screen, there is a high turbulence region resulting in the larger head loss. The pressure distribution of the second tank is uniformity in the course of filter work. However, the pressure of the first tank is significantly higher than the second one.

APA, Harvard, Vancouver, ISO, and other styles

37

KOŁODZIEJ, Szymon, Grzegorz LIGUS, Jarosław MAMALA, and Andrzej AUGUSTYNOWICZ. "Analysis of air flow velocity distribution in the intake system of an SI engine." Combustion Engines 169, no. 2 (May 1, 2017): 152–57. http://dx.doi.org/10.19206/ce-2017-227.

Full text

Abstract:

The conditions of air flow in the intake determine power generated by the engine to a large extent. The biggest resistances in flow of the air sucked or pumped into the engine are generated by the throttle, which is at the same time the main component which allows for regulation of engine power. For the purpose of research conducted in this work, time density of engine work points in analyzed velocity profiles was determined with the use of Engine Road Load Simulator. Thanks to the knowledge of time velocity, it was possible to determine throttle positions at which the engine operates most frequently. With the use of image analysis methods, obtained parameters were experimentally researched, considering flow disturbances which are the effect of air flow through the throttle and uneven air distribution in the intake manifold of a four-cylinder engine.

APA, Harvard, Vancouver, ISO, and other styles

38

Shi, Yun Qiu, and Chuan Sheng Wu. "Research on Access Network Flow Control Management Process." Applied Mechanics and Materials 687-691 (November 2014): 2552–56. http://dx.doi.org/10.4028/www.scientific.net/amm.687-691.2552.

Full text

Abstract:

The urban area of the server can be a central control node switch and server node, the node switches and a server node can know the porttraffic information in real time. When the connection existed over between 2 of these devices, a connection can be selected according to the real-time traffic, real-time routing function to avoid network congestion and flow of the uneven distribution of resources. Similarly, node server can central control node switch can know the real-time node switch port flow information, therefore, the node switches can obtain the terminal flow control information from the server to the terminal node data transmission flow control.

APA, Harvard, Vancouver, ISO, and other styles

39

Pak, E. T., and J. C. Lee. "Performance and pressure distribution changes in a centrifugal pump under two-phase flow." Proceedings of the Institution of Mechanical Engineers, Part A: Journal of Power and Energy 212, no. 3 (May 1, 1998): 165–71. http://dx.doi.org/10.1243/0957650981536835.

Full text

Abstract:

Pump performance characteristics change drastically under two-phase flow conditions from those of single-phase flow. This is due to a change in flow characteristics in the impeller. Owing to a positive pressure gradient the air bubble moves more slowly than the water in the impeller channel, but in the suction surface region of the impeller inlet, where a negative pressure gradient prevails, the bubbles move more quickly than the water. Thus, in the space just after this region the distributions of the void fraction obtained are considerably higher and uneven. The change in the pressure distribution owing to air admission is also particularly evident in the inlet region of the impeller. These changes bring about an alteration of the whole flow pattern in the impeller and also cause a drop in pump performance. The Reynolds-averaged Navier-Stokes equations for two-phase flow in a centrifugal pump impeller are solved using a finite volume method to obtain the pressure, velocities and void fraction respectively. Good agreement is achieved when the predicted results are compared with those measured experimentally within the range of bubbly flow conditions.

APA, Harvard, Vancouver, ISO, and other styles

40

Piven, Mykhailo. "Experimental Studies Of The Specific Load Distribution Of The Mixture Over The Area Of The Inclined Tray." National Interagency Scientific and Technical Collection of Works. Design, Production and Exploitation of Agricultural Machines, no. 50 (2020): 78–87. http://dx.doi.org/10.32515/2414-3820.2020.50.78-87.

Full text

Abstract:

The regularities of specific loading distribution of loose mixture on the area of a working surface of the inclined tray are established in the work. The studies were performed on the experimental setup consisting of a storage hopper and inclined flat trays of different lengths. The material of the study was a grain mixture of winter wheat variety "Myronivska 30". The magnitude of the load was determined using a receiving device, which allowed to obtain the specific load distribution on the width and length of the tray and over time. The specific loading of the tray is uneven in the area of the working surface: the central section is overloaded, and the wall is underloaded. The largest deviations of the specific load at the inlet of the tray, but with length they decrease, approaching a uniform distribution. The specific load profile across the width of the tray is asymmetric and has a local extremum. As the tray length increases, at the certain initial speed and angle, the specific load decreases and the mixture flow slows down. With a constant supply of material from the hopper, there is a gradual accumulation of the mixture in the tray, compaction and growth of the layer, which leads to complete cessation of flow. Uneven loading of the tray occurs due to uneven supply of material from the storage hopper, in which the movement begins. The initial feed varies across the width of the tray and over time, and the nature of the specific load profile formed at the entrance to the tray is preserved for almost its entire length. The movement of the mixture flow in the inclined tray is non-stationary, the specific load varies significantly over the entire surface area and largely depends on the initial conditions of movement. The obtained regularities of specific loading on the working surface area of the tray can be used in the calculation of the modes of loose mixtures movement and substantiation of the equipment parameters for loading the working bodies of machines.

APA, Harvard, Vancouver, ISO, and other styles

41

Walker, B. R. "Evidence for uneven distribution of L-type calcium channels in rat pulmonary circulation." American Journal of Physiology-Heart and Circulatory Physiology 269, no. 6 (December 1, 1995): H2051—H2056. http://dx.doi.org/10.1152/ajpheart.1995.269.6.h2051.

Full text

Abstract:

Experiments were performed on isolated, perfused rat lungs to determine the segmental sites of vasoconstriction in response to factors that open voltage-sensitive, L-type calcium channels on vascular smooth muscle cells. Lungs from male Sprague-Dawley rats were perfused at constant flow with a physiological saline solution (PSS) containing albumin. Measurements were made of pulmonary arterial and venous pressure, whereas capillary pressure was estimated by the double-occlusion technique. After equilibration, lungs were constricted with depolarizing PSS containing high K+ (35 or 45 mM). With both stimuli, approximately 80% of the observed increase in vascular resistance occurred on the arterial side of the circulation. Both nifedipine and verapamil reversed this response; however, reversal was more consistent in the arterial segment. In additional experiments, the L-type channel activator (-)BAY K 8644 caused increased resistance in the arterial but not the venous segment. Another group of lungs constricted with the thromboxane mimetic U-46619 demonstrated equal arterial and venous vasoconstriction. In U-46619-constricted lungs, nifedipine caused a 28% reversal of the agonist-induced increase in arterial resistance but was without effect on the venous circulation. These data suggest that a greater density of L-type calcium channels may exist within the arterial segment of the pulmonary circulation than in the veins.

APA, Harvard, Vancouver, ISO, and other styles

42

FUJITA, Hisashi, Sadao TOMIIE, Kanji SAKAI, and Motoyasu KAMATA. "IMPROVEMENT OF UNEVEN DISTRIBUTION OF OUTLET AIR FLOW RATES FROM SHALLOW AIR PLENUM : Studies on underfloor air distribution system Part 2." Journal of Architecture and Planning (Transactions of AIJ) 64, no. 515 (1999): 89–95. http://dx.doi.org/10.3130/aija.64.89_1.

Full text

APA, Harvard, Vancouver, ISO, and other styles

43

Sun, Tao, Yi Zhang, Hai Ou Sun, and Zhong Yi Wang. "Velocity Field in 90°Curved Duct of Cycle Section." Key Engineering Materials 474-476 (April 2011): 1233–37. http://dx.doi.org/10.4028/www.scientific.net/kem.474-476.1233.

Full text

Abstract:

Flow in curved duct is different from that happens in straight pipeline. Affected by the curved duct curvature, the flow field in a curved duct is uneven. The flow in the curved duct suffers serious loss. Considering the flow field characteristic and engineering applications, the characteristic of the flow field in curved duct without guide plate and the curved duct with different guide plates have been studied based on the numerical results. The velocity distribution and unevenness on the outlet of the curved duct have been analyzed too. Then the best conditions for guide plates installed in curved duct are achieved.

APA, Harvard, Vancouver, ISO, and other styles

44

Liu, Li, Yi Ping Lu, Jia De Han, and Xue Mei Sun. "Numerical Simulation on Air Volume Flow Rate Distribution of Stator Ducts for Salient Pole Synchronous Motor." Applied Mechanics and Materials 644-650 (September 2014): 373–76. http://dx.doi.org/10.4028/www.scientific.net/amm.644-650.373.

Full text

Abstract:

Air volume flow rate distribution of stator ducts along axial and circumferential for salient pole synchronous motor is strongly influenced by the air flow field in the air gap and rotor poles, which is completely different from the flow characteristics of non-salient pole motor and it directly relates to the peak temperature of stator bars and core and axial temperature difference which can affect the safety of the operation. A three-dimensional physical model of 1/8 motor was established and corresponding solution domain boundary conditions were given in this article. The air volume flow rate distribution of stator ducts along axial and circumferential was analyzed based on CFD. The study show that at the same position of the axial stator, the cooling air flow into stator ducts along the circumferential direction is uneven, the air volume flow rate distribution is largely influenced by rotor pole pieces, geometry and position of pole support block and rotor rotation direction.

APA, Harvard, Vancouver, ISO, and other styles

45

Tian, Shu-Ling, Ying-Ying Shen, Yao Li, Hai-Bo Wang, Sheryar Muhammad, and Hai-Qing Si. "Numerical simulation of flow distribution in the header of plate-fin heat exchanger." International Journal of Modern Physics B 34, no. 14n16 (April 20, 2020): 2040111. http://dx.doi.org/10.1142/s0217979220401116.

Full text

Abstract:

Plate-fin heat exchangers are widely used in industry at present due to their compact structure and high efficiency. However, there is a problem of flow maldistribution, resulting in poor performance of heat exchangers. The influence of the header configuration on fluid flow distribution is studied by using CFD software FLUENT. The numerical results show that the fluid flow inside the header is seriously uneven. The reliability of the numerical simulation is validated against the published results. They are found to be basically consistent within considerable error. The optimal number of the punch baffle is investigated. Various header configuration with different opening ratios have been studied under the same boundary conditions. The gross flow maldistribution parameter (S) is used to evaluate flow nonuniformity, and the flow maldistribution parameters of different schemes under different Reynolds numbers are listed and compared. The optimal header with minimum flow maldistribution parameter is obtained through the performance analysis of headers. It is found that the flow maldistribution of the improved header is significantly smaller compared with the conventional header. Hence, the efficiency of the heat exchanger is effectively enhanced. The conclusion provides a reference for the optimization design of plate-fin heat exchanger.

APA, Harvard, Vancouver, ISO, and other styles

46

Lichtzinder, Boris Ya, Igor A. Blatov, and Elena V. Kitaeva. "ON ESTIMATES OF THE AVERAGE QUEUE LENGTH FOR MASS SERVICE SYSTEMS IN CASE OF CORRELATED INPUT FLOW." T-Comm 14, no. 8 (2020): 13–20. http://dx.doi.org/10.36724/2072-8735-2020-14-8-13-20.

Full text

Abstract:

In multiservice packet-switched networks, the packet flow differs significantly from the Poisson flow, since these flows are generated by many sources of requests for services that are significantly different from each other. All this leads to the fact that the flows in multiservice networks are characterized by uneven arrival of requests and packets. Packages are grouped into "bundles" at some time intervals and are practically absent at other intervals. The random process of claims (packets) entering the system is characterized by a distribution law that establishes a relationship between the values ??of a random variable and the probabilities of occurrence of the indicated values. In most cases, such a flow is characterized by a distribution function of time intervals between neighboring claims, and the process of their processing is characterized by a probability distribution function of service time intervals. The mathematical model of the simplest single-channel queuing systems (QS) in case of incoming flow with arbitrary correlation. For this QS, various generalizations of the Khinchin-Pollachek formula of the average queue length. An interval model of the incoming flow is proposed, within which an expression of the average queue length through unconditional moments is obtained second order. All results were obtained with very general assumptions of ergodicity and stationarity. Are given results of numerical experiments confirming theoretical conclusions.

APA, Harvard, Vancouver, ISO, and other styles

47

Fukuda, Ryosuke, Tomokazu Sato, and Masakazu Kato. "Study on Frequency Control Method to Suppress Power Flow Fluctuation with Uneven Distribution of Wind Power Generation." IEEJ Transactions on Power and Energy 133, no. 7 (2013): 616–22. http://dx.doi.org/10.1541/ieejpes.133.616.

Full text

APA, Harvard, Vancouver, ISO, and other styles

48

Cui, Li Kun, Yong Zhi Zhang, and Zhuo Li. "Numerical Simulation of 3-D Chemical Non-Equilibrium Flow in the Afterburning Chamber of Solid Ducked Rocket." Applied Mechanics and Materials 130-134 (October 2011): 3151–54. http://dx.doi.org/10.4028/www.scientific.net/amm.130-134.3151.

Full text

Abstract:

In order to reveal the complex turbulent combustion processes in the afterburning chamber of Solid Ducked Rocket (SDR), Based on the fundamental equations of hydrokinetics and elementary principles of radical reaction kinetics, using multi-component chemical reaction equation of containing Mg and Al components, the numerical simulation of chemical non-equilibrium flow in the afterburning chamber of SDR is processed and effects of the air inlet angle on the afterburning chamber is studied by using Fluent software. The results show that pressure distribution is more balanced, temperature distribution is very uneven and flow is extremely complicated in the afterburning chamber. Combustion efficiency can be increased by improving the air inlet angle.

APA, Harvard, Vancouver, ISO, and other styles

49

Lü, Wen Long, Zhan Zhan, Xiao Hui Du, Ru Hai Zhou, Hao Er Zhang, Ling Yun Wang, and Dao Heng Sun. "Study of PSG Thickness Uniformity Influencing Factors in LPCVD." Key Engineering Materials 645-646 (May 2015): 3–8. http://dx.doi.org/10.4028/www.scientific.net/kem.645-646.3.

Full text

Abstract:

In the fabrication of SiC high-temperature sensors, the phosphosilicate glass film (PSG) is deposited on the SiC wafer as the intermediate layer, achieving the bonding of two SiC wafers. The ease of bonding is affected by the PSG film thickness uniformity. In this paper, the flow field distribution in the LPCVD tube is simulated under different deposition conditions,obtaining the wafer surface uniformity of gas flow distribution, which was verified by the experiment, The aim of this work is to study the impact of several deposition conditions such as the location of SiC wafers, wafer inclination and wafer spacing on the thickness uniformity of PSG film. Experimental results show that SiC wafer position in the tube and its own inclination and wafer spacing affect gas flow field on the SiC wafer surface,leading to uneven distribution of gas flow, thus affect the thickness uniformity of PSG.

APA, Harvard, Vancouver, ISO, and other styles

50

Dai, Nai Chang, and Sheng Dong Yu. "Research on Particle Flow Erosion Precision Electroforming Technology." Advanced Materials Research 771 (September 2013): 75–81. http://dx.doi.org/10.4028/www.scientific.net/amr.771.75.

Full text

Abstract:

t is possible to get electroforming deposit with numerous special functions by adoption of traditional electroforming technique, but in which there are defects such as uneven electroforming deposit and unstable performance, etc. In order to enhance the quality and speed of electroforming deposit, this article has proposed the particle flow erosion precision electroforming technology, particle flows such as huge amount of micro glass bead is used in the process of electro-deposit for erosion of electroforming deposit surface, so that micro glass beads continuously abrade and impact cathode surface. As indicated in electroforming test of metallic nickel, in comparison with traditional electroforming technology, particle flow erosion precision electroforming technology can effectively change the microscopic structure of electroforming deposit, refine grain and realize evener distribution of grains, so as to reduce the diffracted intensity of all crystal faces and enhance mechanical property of electroforming deposit.

APA, Harvard, Vancouver, ISO, and other styles

Journal articles on the topic 'Uneven flow distribution'

Create a spot-on reference in APA, MLA, Chicago, Harvard, and other styles