scholarly journals Influence of Nozzle Geometry on Fluid Flow Parameters

2020 ◽  
Vol 25 (4) ◽  
pp. 214-222
Author(s):  
I. Penkov ◽  
D. Aleksandrov
Keyword(s):  
Radial Direction ◽  
Optimal Solution ◽  
Front Surface ◽  
Axial Direction ◽  
Air Pressure ◽  
Nozzle Geometry ◽  
Air Velocity ◽  
Flow Parameters ◽  
Nozzle Axis ◽  
Nozzle Hole

AbstractThe article discusses ways for optimization of a standard nozzle cup design to achieve a narrower paint flow. The analysis of a standard nozzle cup shows that distribution of air pressure is critically uneven both along the nozzle axis and in the radial direction. A decrease in pressure is about 45% at the distance of 2 mm from the front surface of the nozzle cup. Air pressure decreases about 40% at the distance of 2 mm from the nozzle axis in the radial direction. Air velocity decreases about 52% at the distance of 4 mm from nozzle surface but then the velocity stabilizes and decreases is about 59% at the distance of 10 mm from the nozzle surface in comparison to its magnitude on the nozzle surface.Six extra holes and a circular rim were added to the standard nozzle cup to obtain paint stream as narrow as possible. Also was modified inner surface of the nuzzle cup. Totally, four different components were analysed. The results show that with increasing the nozzle cone by fifteen or more degrees, the pressure distribution decreases. Most optimal solution has six small holes around the nozzle hole and a small rim covering all holes. In this case, pressure decreases only 3% in the axial direction and 4% in the radial direction at the distance of 2 mm from the front surface of the nozzle. Distribution of air velocity is still significant but its magnitude is about 35% … 45% less than at the standard nozzle cup.

Analysis of Vibration Caused by Electromagnetic Force on Stator End-Winding of Large Dry Submersible Motor

2013 ◽  
Vol 416-417 ◽  
pp. 428-432
Author(s):  
Li Shan ◽  
Xiao Wei Cheng ◽  
Yong Fang ◽  
Xiao Hua Bao
Keyword(s):  
Electromagnetic Field ◽  
Steady State ◽  
Transition State ◽  
Electromagnetic Force ◽  
Radial Displacement ◽  
Radial Direction ◽  
Axial Direction ◽  
Axial Displacement ◽  
Force Density ◽  
Submersible Motor

This paper investigates the vibration which caused by electromagnetic on the stator end-winding of the large dry submersible motor. Firstly, the electromagnetic field which included transition state and steady state is researched by 3-D FEM. Secondly, the electromagnetic force which lead to vibrations of end-winding is calculated by numerical method, it can be obtained that where endured the largest force density along the slant part of end-winding. Finally, the radial displacement and the axial displacement of the slant part which caused by vibrations is studied, the analysis results show that the axial displacement is larger than the amplitude of radial displacement. It indicates that the slant part of end-winding will be more easily damaged at axial direction than radial direction.

Numerical Investigation of the Influence of Flow Parameters Nonuniformity at the Diffuser Inlet on Characteristics of the GTE Annular Combustion Chamber

2015 ◽  
Author(s):  
Sergey S. Matveev ◽  
Ivan A. Zubrilin ◽  
Mikhail Yu. Orlov ◽  
Sergey G. Matveev
Keyword(s):  
Combustion Chamber ◽  
Dynamic Pressure ◽  
Air Distribution ◽  
Gas Generator ◽  
Air Velocity ◽  
Degree Polynomial ◽  
Flow Dynamic ◽  
Ansys Fluent ◽  
Flow Parameters ◽  
Mode Of Operation

Parameters at a combustion chamber’s inlet significantly vary in an aircraft engine’s transient states of operation. At the same time, there is a significant spatial heterogeneity of flow parameters at a diffuser inlet of a combustion chamber, which is defined by nature of flow in a compressor and an individual for each mode of operation of a specific gas generator. In this paper presented a study of an influence of radial and circumferential nonuniformities of flow parameters on characteristics of a combustion chamber. Multi spray for annular combustion chamber with two rows of burner is considered. Z-shaped sector, which contains two nozzles of outer and two nozzles of inner row, was selected as the calculated domain. Calculations were carried out in ANSYS Fluent 14.5 software package with an implementation of cluster analysis. Nonuniformity at a diffuser inlet was set as fifth degree polynomial, which was derived from a numerical simulation of a compressor. As a result it was established, that radial nonuniformity of flow parameters at an inlet of a combustion chamber influences on characteristics of a combustion chamber. A stretched shape of velocity profile contributes to higher air flow dynamic pressure on dome than using uniform profile air velocity. At that, local equivalents ratio excess are changing, and consequently, sizes and location NOx production zones are changing as well. The residual rotation of flow from the compressor leads to a lesser effect on total pressure drop and air distribution in flame tube. The obtained results showed that, during a design of a combustion chamber, it is necessary to take into account nonuniformity of parameters’ distribution at its inlet.

Influence of Structure of Electrode Array on Logging. The Resistivity Logging Response through Casing of Structure of Electrode Array

2014 ◽  
Vol 1006-1007 ◽  
pp. 990-993
Author(s):  
An Ling Wang ◽  
Fu Ping Liu
Keyword(s):  
Radial Direction ◽  
Recurrence Formula ◽  
Electrode Array ◽  
Axial Direction ◽  
Formation Model ◽  
Line Equation ◽  
Metal Casing ◽  
Resistivity Logging ◽  
Important Significance ◽  
Computing Speed

Because difference of formation model affects the potential distribution on the metal casing, the resistivity logging response can be obtained through casing by measuring the potentials on the metal casing. In fact, the logging responses are the comprehension effects of complex formation and metal casing, so that in the coefficients of transmission line equation (TLE), we should consider the effects of formation model in radial-direction. In the following, for the formation taking on six-layer in axial-direction, and step in radial-direction, the resistivity logging responses through casing are researched and discussed, and given the recurrence formula to compute potential. Draw the curve of the resistivity logging response through casing of six-layer formations. The conductivity of formation is computed is very approximating to that of formation model. The computing examples also show that this method has a fast computing speed (the run time of computing example is less than 1s). For analysis the logging response of six-layers and block formations, and the design of logging instruments, the research is important significance and useful.

Mechanical Model of Non-Magnetic Particles Centrifugal Separation in Magnetic Fluid

2013 ◽  
Vol 820 ◽  
pp. 225-228
Author(s):  
Tong Li ◽  
Jing Tao Wei ◽  
Ji Li
Keyword(s):  
Centrifugal Force ◽  
Magnetic Fluid ◽  
Mechanical Model ◽  
Radial Direction ◽  
Magnetic Particles ◽  
Axial Direction ◽  
Separation Mechanism ◽  
Centrifugal Separation

It is difficult to sort fine non-magnetic particles only by the buoyancy of magnetic fluid. Therefore, based on the magneto hydrostatic separation, the centrifugal separation under the condition of centrifugal force would be an effective method to improve the efficiency. By establishing the mechanical model of centrifugal separation in magnetic fluid, this paper analyzes the kinematical equations of non-magnetic particles in three directionstangential direction, radial direction, and axial direction, and then theoretically explores the separation mechanism of this method.

scholarly journals Solid Rocket Motor Design Using Hybrid Optimization

2012 ◽  
Vol 2012 ◽  
pp. 1-9 ◽  
Author(s):  
Kevin Albarado ◽  
Roy Hartfield ◽  
Wade Hurston ◽  
Rhonald Jenkins
Keyword(s):  
Hybrid Approach ◽  
Optimal Solution ◽  
Solution Space ◽  
Axial Direction ◽  
Pattern Search ◽  
Rocket Motor ◽  
Solid Rocket Motor ◽  
Thin Sections ◽  
Solid Rocket

A particle swarm/pattern search hybrid optimizer was used to drive a solid rocket motor modeling code to an optimal solution. The solid motor code models tapered motor geometries using analytical burn back methods by slicing the grain into thin sections along the axial direction. Grains with circular perforated stars, wagon wheels, and dog bones can be considered and multiple tapered sections can be constructed. The hybrid approach to optimization is capable of exploring large areas of the solution space through particle swarming, but is also able to climb “hills” of optimality through gradient based pattern searching. A preliminary method for designing tapered internal geometry as well as tapered outer mold-line geometry is presented. A total of four optimization cases were performed. The first two case studies examines designing motors to match a given regressive-progressive-regressive burn profile. The third case study studies designing a neutrally burning right circular perforated grain (utilizing inner and external geometry tapering). The final case study studies designing a linearly regressive burning profile for right circular perforated (tapered) grains.

USE OF SOLID STATE NUCLEAR TRACK DETECTORS CR-39 TO STUDY CHARGED PARTICLES EMISSION FROM A 3 kJ PLASMA FOCUS

1995 ◽  
Vol 09 (16) ◽  
pp. 1033-1037
Author(s):  
M. ZAKAULLAH ◽  
IMTIAZ AHMAD ◽  
KHAIRUR REHMAN ◽  
G. MURTAZA
Keyword(s):  
Charged Particle ◽  
Solid State ◽  
Plasma Focus ◽  
Radial Direction ◽  
Particle Flux ◽  
Charged Particles ◽  
Axial Direction ◽  
Low Energy ◽  
Nuclear Track Detectors

The CR-39 solid state nuclear track detectors are employed to investigate the fluence anisotropy of charged particles (protons, deuterons and tritons) emitted from the focus region of a low energy Mather-type plasma focus energized by a single 32 μF, 15 kV (3.6 kJ) capacitor. The charged particle flux is the highest in the axial direction, and decreases towards the radial direction. The radial charged particles flux is six times smaller than the flux in the axial direction.

scholarly journals Experimental Study on Atomization of Plain Jet Injector Under High Pressure Co-Axial Air Flow

1987 ◽  
Author(s):  
Gui Xiang Yang ◽  
J. S. Chin
Keyword(s):  
Experimental Study ◽  
High Velocity ◽  
Drop Size ◽  
Air Flow ◽  
Test Chamber ◽  
Back Pressure ◽  
Air Pressure ◽  
Working Fluid ◽  
Air Velocity ◽  
Pressure Drops

An experimental study has been conducted on the effect of high back pressure on the spray characteristics of a plain jet injector under coaxial high velocity air flow. The air pressures tested range from 1 to 16 atm, the range of air velocity is 60–120 m/s, the pressure drops of injector tested are 200–2000 kpa. Working fluid is water. Injector hole diameter is 0.5 mm. The key feature of the experiment is using a convergent-divergent nozzle to maintain a high air pressure inthe test chamber and at the same time to maintain a high velocity air flow in the atomization zone. Such an experimental arrangement totally eliminates air and droplets recirculation in the test chamber and problem related to slow droplet settling in a commonly used pressurized vessel for high back pressure atomization research. The results show that SMD decreases monotonicly with the increase of back pressure or air velocity, at different air velocities, the effect of air pressure is different. The drop size distribution parameter N in Rosin-Rammler distribution decreases slightly with increase of back pressure or air velocity.

scholarly journals Mathematical modeling of spatial gas flow in nozzles of nontrivial geometry

2021 ◽  
Vol 2094 (4) ◽  
pp. 042002
Author(s):  
S A Bitkin ◽  
M A Korepanov ◽  
M R Koroleva ◽  
A I Karpov ◽  
S S Makarov
Keyword(s):  
Gas Flow ◽  
Three Dimensional ◽  
Critical Section ◽  
Nozzle Geometry ◽  
Outlet Section ◽  
Flow Area ◽  
Flow Parameters ◽  
Inviscid Gas ◽  
Three Dimensional Models ◽  
The Mathematical Model

Abstract Numerical modeling of the spatial gas flow in an adjustable nozzle with an asymmetric critical section caused by the overlap of a part of the flow area by a gas flow regulator has been carried out. The mathematical model is based on three-dimensional models of gas dynamics, the method of large particles is used for calculation. When describing the unsteady flow of an inviscid gas, the system of Euler equations is used, written for a computational rectangular plane, taking into account the function of nozzle geometry. The results of calculations of flow parameters along a nozzle path with a uniform outlet section and with an obliquely cut outlet nozzle are presented. Calculations were carried out for completely open critical sections and for half overlapped. For oblique cut nozzles, the overlap of the critical section from the side of the short part and from the side of the long part of the oblique nozzle is considered.

Pitting Corrosion Diagnosis of Bearing Based on Power Cepstrum and Histogram

2012 ◽  
Vol 512-515 ◽  
pp. 1672-1676 ◽  
Author(s):  
Shu Fang ◽  
De Liang Li ◽  
Li Tao Liu ◽  
Zhen Wei Zhang
Keyword(s):  
Pitting Corrosion ◽  
Vibration Amplitude ◽  
Radial Direction ◽  
Impact Force ◽  
Axial Direction ◽  
High Impact ◽  
New Method ◽  
Outer Ring ◽  
Heavy Load ◽  
Bearing Race

The axle assembly of fire robot need endure both heavy load and high impact force, and the pitting corrosion in the bearing race become a commom fault. In this paper, the vibration of bearing both in the inner ring and outer ring was analyzed, the characteristics of bearing with pitting corrosion were also analyzed, and based on those characteristics a new method for pitting corrosion diagnosis were proposed, in this method the power cepstrum in the axial direction and histogram of the vibration amplitude in the radial direction were used for detecting the pitting corrosion of bearing, and experiments results proved the practicability and effectiveness of this method.

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