Turbulence Flow Analysis of Low Temperature Propellant Flowing through Pipes of Filling System

2011 ◽  
Vol 480-481 ◽  
pp. 585-589
Author(s):  
Jian Jun Song ◽  
Xiao Ping Du ◽  
Ji Guang Zhao ◽  
Jing Peng Chen ◽  
Qiao Wang ◽  
...  
Keyword(s):  
Flow Analysis ◽  
Simulation Method ◽  
Liquid Hydrogen ◽  
Actual Condition ◽  
Tube Length ◽  
Inlet Section ◽  
Turbulence Flow ◽  
Filling System ◽  
Launch Site ◽  
Simulation Results

With aiming at the problem of liquid hydrogen flowing through filling system in space launch site, the author set up a turbulence model and coupled with the analysis of turbulence condition of liquid hydrogen in tube. Based on the computational fluid dynamics, the flow field was studied according to the numerical simulation method. Then, the changes of flow parameters i.e. pressure and velocity at the tube were observed. Simulation results showed that, in the inlet-section, there existed boundary-layer, besides, the velocity and pressure which changed continually was not stable until the liquid hydrogen flowed through on-way. In addition, in water-carrying section of turbulence flow, the velocity distribution was even and there was no obvious delamination which explained that the mix was intense. The velocity near the surface of the tube was about zero and the pressure turned to smaller with the increase of tube length. As a result of the pressure drop, there existed the loss of on-way. The above simulation results which provided the theoretical basis for liquid hydrogen study accorded with the actual condition.

Laminar Flow Analysis of Low Temperature Propellant Flowing through Pipes of Filling System

2011 ◽  
Vol 480-481 ◽  
pp. 580-584
Author(s):  
Jian Jun Song ◽  
Xiao Ping Du ◽  
Ji Guang Zhao ◽  
Jing Peng Chen ◽  
Qiao Wang ◽  
...  
Keyword(s):  
Laminar Flow ◽  
Flow Analysis ◽  
Simulation Method ◽  
Liquid Hydrogen ◽  
Actual Condition ◽  
Tube Length ◽  
Inlet Section ◽  
Filling System ◽  
Launch Site ◽  
Simulation Results

With aiming at the problem of liquid hydrogen flowing through filling system in space launch site, the author set up a math model of laminar flow and coupled with the analysis of laminar flow condition of liquid hydrogen in tube. Based on the computational fluid dynamics, the flow field was studied according to the numerical simulation method. Then, the changes of flow parameters i.e. pressure and velocity at the tube were observed. Simulation results showed that, in the inlet-section, there existed boundary-layer, besides, the velocity and pressure which changed continually was not stable until the liquid hydrogen flowed through on-way. In addition, the velocity distributed in the form of rotary parabolic surface whose axis was the tube’s axis itself in water-carrying section of on-way. The velocity near the surface of the tube was about zero and the pressure turned to smaller with the increase of tube length. As a result of the pressure drop, there existed the loss of on-way. The above simulation results which provided the theoretical basis for liquid hydrogen study accorded with the actual condition.

The Impact of Low-Temperature Liquid Hydrogen Filling System on the Bend Pipe

2011 ◽  
Vol 480-481 ◽  
pp. 810-814
Author(s):  
Jian Jun Song ◽  
Xiao Ping Du ◽  
Ji Guang Zhao ◽  
Jing Peng Chen ◽  
Qiao Wang ◽  
...  
Keyword(s):  
Numerical Simulation ◽  
Flow Field ◽  
Simulation Method ◽  
Liquid Hydrogen ◽  
Bend Pipe ◽  
Numerical Simulation Method ◽  
Filling System ◽  
Launch Site ◽  
The Impact ◽  
Pipe Vibration

The launch site security issues have been became the focus of the world’s research for several decades. Aiming at the filling system, the pipe vibration caused by the liquid hydrogen which flowed through the bend pipe was studied. And based on the computational fluid dynamics, the flow field was simulated according to the numerical simulation method. Then, the changes of flow parameters i.e. pressure and velocity at the bend were observed. The simulation results showed that: (1) the speed and the pressure of the liquid hydrogen would have a sudden change which was caused by flow direction and it would create a vortex which could erode the pipe and lead to the pipe vibration in the region. As a result, the pipe would deteriorate caused by the vortex. (2) the flow field analysis using the numerical simulation method was feasible. And the method provided a flow field distribution directly and design basis for filling system pipes.

Study of HVDC System and Subsynchronous Oscillation

2015 ◽  
Vol 1092-1093 ◽  
pp. 356-361
Author(s):  
Peng Fei Zhang ◽  
Lian Guang Liu
Keyword(s):  
Power Plant ◽  
Time Domain ◽  
Simulation Method ◽  
Time Domain Simulation ◽  
Stable Convergence ◽  
Turbine Generator ◽  
Plant Model ◽  
Subsynchronous Oscillation ◽  
Hvdc System ◽  
Simulation Results

With the application and development of Power Electronics, HVDC is applied more widely China. However, HVDC system has the possibilities to cause subsynchronous torsional vibration interaction with turbine generator shaft mechanical system. This paper simply introduces the mechanism, analytical methods and suppression measures of subsynchronous oscillation. Then it establishes a power plant model in islanding model using PSCAD, and analyzes the effects of the number and output of generators to SSO, and verifies the effect of SEDC and SSDC using time-domain simulation method. Simulation results show that the more number and output of generators is detrimental to the stable convergence of subsynchronous oscillation, and SEDC、SSDC can restrain unstable SSO, avoid divergence of SSO, ensure the generators and system operate safely and stably

A Reformative Simulation Method of Motor Pole Core Vibration Characteristics

2013 ◽  
Vol 331 ◽  
pp. 118-123
Author(s):  
Tian Hui Ding ◽  
Yun Hua Chen ◽  
Lei Tian
Keyword(s):  
Reference Value ◽  
Simulation Method ◽  
Vibration Characteristics ◽  
New Method ◽  
Motor Design ◽  
Simulation Results ◽  
Vibration Performance

As to directing motor design, it is very important to make sure that the motor’s forecast of vibration performance has reference value. So, it must need motor’s parts vibration characteristics simulation results are so close to their characteristics. This paper puts forward a new simulation method of motor pole core vibration characteristics, this method includes setting anisotropy material attributes multipartite, getting attributes parameters values which are based on recommended fitting curves, modeling and equating windings, equating dipping lacquer and so on. Combining with experiments, the new method is validated its availability.

Simulation Investigation of Tangential-Feed Centerless Grinding Process Performed on Surface Grinder

2009 ◽  
Vol 626-627 ◽  
pp. 23-28
Author(s):  
Wei Xing Xu ◽  
Yong Bo Wu ◽  
Takashi Sato ◽  
Wei Min Lin
Keyword(s):  
Elastic Deformation ◽  
Process Parameters ◽  
Simulation Method ◽  
Machining Accuracy ◽  
Grinding Process ◽  
Elasticity Parameter ◽  
Grinding Method ◽  
Centerless Grinding ◽  
Simulation Results ◽  
Grinding Technique

In our previous study, a new centerless grinding method using surface grinder was proposed. This paper describes a simulation method for investigating the workpiece rounding process in which a model taking the elastic deformation of the machine into consideration is created, and revealing how the process parameters affect the machining accuracy in the new grinding technique. In addition, a practice way to determine the machining-elasticity parameter showing the elastic deformation is developed. The simulation results are compared to show the effect of process parameters on the machining accuracy.

Numerical Simulation of the Stress Field of Thick 7B04 Aluminum Alloy Board during Continuous Manufacture Procedure

2007 ◽  
Vol 127 ◽  
pp. 259-264
Author(s):  
Hong Yuan Fang ◽  
Cheng Iei Fan
Keyword(s):  
Numerical Simulation ◽  
Aluminum Alloy ◽  
Stress Concentration ◽  
Stress Field ◽  
Solution Treatment ◽  
Simulation Method ◽  
The Core ◽  
Manufacturing Procedure ◽  
Continuous Manufacture ◽  
Simulation Results

Numerical simulation method is employed in the article to analyze the stress field of thick 7B04 aluminum alloy board during manufacturing procedure of solution treatment, calendaring and stretching. The simulation results show that the surface of the board endures compressive stress while the core segment endures tensile stress, and the distribution of the stress is very inhomogeneous. The calendaring procedure helps to decrease the stress and redistribute the stress uniformly, but it also leads to stress concentration at the two ends of the board, which engenders bad influence on the subsequent processing. The board deforms plastically when being stretched, thus the stress decreases greatly and is redistributed uniformly.

scholarly journals Numerical Simulation Study on the Front Shape and Thermal Stresses in Growing Multicrystalline Silicon Ingot: Process and Structural Design

Crystals ◽  
2020 ◽  
Vol 10 (11) ◽  
pp. 1053
Author(s):  
Chengmin Chen ◽  
Guangxia Liu ◽  
Lei Zhang ◽  
Guodong Wang ◽  
Yanjin Hou ◽  
...  
Keyword(s):  
Numerical Simulation ◽  
Thermal Stress ◽  
Thermal Stresses ◽  
Simulation Method ◽  
Power Ratio ◽  
Radial Temperature ◽  
Front Shape ◽  
Simulation Results ◽  
Insulation Block ◽  
Transient Numerical Simulation

In this paper, a transient numerical simulation method is used to investigate the effects of the two furnace configurations on the thermal field: the shape of the melt–crystal (M/C) interface and the thermal stress in the growing multicrystalline ingot. First, four different power ratios (top power to side power) are investigated, and then three positions (i.e., the vertical, angled, and horizontal positions) of the insulation block are compared with the conventional setup. The power ratio simulation results show that with a descending power ratio, the M/C interface becomes flatter and the thermal stress in the solidified ingot is lower. In our cases, a power ratio of 1:3–1:4 is more feasible for high-quality ingot. The block’s position simulation results indicate that the horizontal block can more effectively reduce the radial temperature gradient, resulting in a flatter M/C interface and lower thermal stress.

Flow Analysis of Spray Jet and Direct Jet Nozzle for Fire Water Monitor

2010 ◽  
Vol 139-141 ◽  
pp. 913-916 ◽  
Author(s):  
Guo Liang Hu ◽  
Wei Gang Chen ◽  
Zhi Gang Gao
Keyword(s):  
Flow Analysis ◽  
Flow Characteristics ◽  
Flow Simulation ◽  
Jet Flow ◽  
Extended Length ◽  
Jet Nozzle ◽  
Simulation Results ◽  
Steady Velocity ◽  
Nozzle Structure

In order to investigate the influence rules between the jet nozzle of fire water monitor and the jet performances, two typical jet nozzle, the spray jet and direct jet nozzle was designed to analysis the jet flow characteristics. Flow simulation of the jet nozzle was completed using fluent kits. The outlet velocity of the spray jet nozzle and direct jet nozzle were investigated in detail, and the influence rules of the nozzle structure on the outlet velocity was also discussed. The simulation results show that the steady velocity of the jet nozzle is about 34m/s that coinciding the contour magnitude, and the better extended length of the direct jet nozzle is about 50mm length that can improve the jet performances. The results can verify the reasonableness of the designed nozzle, it also can optimize the nozzle structure and increase the jet performance of the fire water monitor.

Qualitative simulation of organization quality specific immune decision-making of manufacturing enterprises based on QSIM algorithm simulation

2021 ◽  
pp. 1-18
Author(s):  
Qiang Liu ◽  
Xiaoli Qu ◽  
Danyu Zhao ◽  
Yu Guo
Keyword(s):  
Decision Making ◽  
Simulation Method ◽  
Engineering Management ◽  
Decision Variable ◽  
Science And Engineering ◽  
Qualitative Simulation ◽  
Manufacturing Enterprises ◽  
Decision Variables ◽  
Organization Quality ◽  
Simulation Results

Quality is the core of the enterprise, strengthening organization quality specific immune is the key channel. Organization quality specific immune belongs to science and engineering management field, QSIM qualitative simulation method that refer to computational simulation algorithm is widely used in the science and engineering management field, QSIM qualitative simulation method can solve science and engineering management issues effectively. In this study, qualitative simulation QSIM theory is used to analyze and reason the organization quality specific immune decision of manufacturing enterprises. Combined with the pressure-state-response framework, the management mechanism of organization quality specific immune is analyzed according to state variables, decision variables, system variables and environment variables, and further the qualitative simulation rules for organization quality specific immune decision-making are set according to the causal relationships among variables of organization quality specific immune. This study sets organization quality monitor, organization quality defense and organization quality memory as the decision variables, uses QSIM algorithm for simulating organization quality specific immune decision-making reasoning, compares with the influences of single decision variable and multi-decision variables on organization quality specific immune system through simulation results. Simulation results indicate that QSIM algorithm simulation can be used to simulate and reason organization quality specific immune decision-making in order to help manufacturing enterprises reasonably enhance organization quality specific immune performance and quality performance through three decision variables of organization quality monitor, organization quality defense and organization quality memory. The simulation results will provide new revelation for organization quality specific immune decision-making of manufacturing enterprises.

scholarly journals Hybrid Method of Modal Analysis and Laser Shock Scanning to Visualize the Pyroshock Propagation in a Tension Joint

2019 ◽  
Vol 2019 ◽  
pp. 1-13
Author(s):  
Yong-Woon Kim ◽  
Jae-Kyeong Jang ◽  
Jung-Ryul Lee ◽  
Hak-Seong Gim
Keyword(s):  
Modal Analysis ◽  
Hybrid Method ◽  
Response Spectrum ◽  
Near Field ◽  
Low Frequency ◽  
Simulation Method ◽  
Experimental Simulation ◽  
Laser Shock ◽  
Simulation Results ◽  
Tension Joint

The use of pyrodevices in the aerospace industry has been increasing because of their ability to implement separation missions with a small weight, for example, space launchers, spacecrafts, and missiles. During operation, pyrodevices generate pyroshock, which causes failures of electronic devices. Recently, a pyroshock simulation method using laser shock has been developed to evaluate the risk of pyroshock before flight mission. However, depending on the structure, the laser shock showed some difficulty simulating pyroshock in the low-frequency regime accompanying vibration. Therefore, in this study, we developed a hybrid method of numerical modal analysis and laser shock-based experimental simulation to visualize the pyroshock propagation in all the relevant frequency regimes. For the proof of concept of the proposed method, we performed experiments of explosive bolt-induced shock and pyrolock-induced shock in the open-box-type tension joint and compared the hybrid simulation results with actual pyroshock. From the results, we obtained the simulated time-domain signal with an averaged peak-to-peak acceleration difference (PAD) of 11.2% and the shock response spectrum (SRS) with an averaged mean acceleration difference (MAD) of 28.5%. In addition, we were able to visualize the simulation results in the temporal and spectral domains to compare the pyroshock induced by each pyrodevice. A comparison of the simulations showed that the pyrolock had an impulse level of 1/12 compared to the explosion bolt. In particular, it was confirmed that the pyrolock-induced shock at the near field can cause damage to the electronic equipment despite a smaller impulse than that of the explosive bolt-induced shock. The hybrid method developed in this paper demonstrates that it is possible to simulate pyroshock for all the frequency regimes in complex specimens and to evaluate the risk in the time and frequency domain.

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