scholarly journals Study on the Vortex in a Pump Sump and Its Influence on the Pump Unit

2022 ◽  
Vol 10 (1) ◽  
pp. 103
Author(s):  
Xijie Song ◽  
Chao Liu ◽  
Zhengwei Wang
Keyword(s):  
Numerical Simulation ◽  
Negative Pressure ◽  
Vortex Core ◽  
Vortex Tube ◽  
Simulation Method ◽  
Development Stage ◽  
Pump Unit ◽  
Pump Performance ◽  
Pump Sump ◽  
Attached Vortex

The vortex in a pump sump is a negative problem for the pump unit, which can lead to the decline of pump performance. Focusing on the internal pressure characteristics of the floor-attached vortex (FAV) and its influence on the pump unit, the FAV was analyzed adopting the previously verified numerical simulation method and experiment. The results show that the pressure in the vortex core gradually decreases with time, drops to a negative pressure at the development stage, and then reaches the lowest pressure during the continuance stage. When the negative pressure of the vortex tube is around the vaporization pressure of the continuance stage, it can cause a local cavitation at the impeller inlet. The evolution of the FAV is accompanied by a change of pressure gradient in the vortex core which is discussed in detail. This research provides theoretical guidance for a better understanding of the vortex characteristics and the optimal design for the pump.

Research on Residual Oil Distribution Regular with the Application of Facies Controlled Modeling and Reservoir Numerical Simulation

2012 ◽  
Vol 616-618 ◽  
pp. 126-132 ◽  
Author(s):  
Hua Bin Wei ◽  
Shang Ming Shi ◽  
Pan Zhao ◽  
Dong Kai Huo ◽  
Wan Zhen Zhu
Keyword(s):  
Numerical Simulation ◽  
Three Dimensional ◽  
Simulation Method ◽  
Structural Features ◽  
Development Stage ◽  
Water Flooding ◽  
Residual Oil ◽  
Distribution Law ◽  
North West ◽  
Oil Distribution

The high water cut stage on the residual oil distribution regularity in late development stage of oilfield is difficult in Daqing oilfield, North West Water Flooding fine demonstration zone development time is long, well under the complicated characteristic, adopts phase control of three-dimensional geological modeling and the method of reservoir numerical simulation in the demonstration zone, structural features and sedimentary characteristics of based on the establishment of demonstration zone, three-dimensional geological model. Through the application of fine reservoir numerical simulation method for the numerical simulation of remaining oil, and a summary of the demonstration zone of residual oil distribution law and cause of formation, provides reliable basis for the next step of oilfield development adjustment.

scholarly journals Study on Numerical Simulation of Fire Danger Area Division in Mine Roadway

2021 ◽  
Vol 2021 ◽  
pp. 1-13
Author(s):  
Hu Wen ◽  
Yin Liu ◽  
Jun Guo ◽  
Ze Zhang ◽  
Mingyang Liu ◽  
...  
Keyword(s):  
Numerical Simulation ◽  
High Temperature ◽  
Gas Flow ◽  
Concentration Field ◽  
Environmental Parameters ◽  
Simulation Method ◽  
Development Stage ◽  
Calculation Model ◽  
Mine Fire ◽  
Mine Roadway

High-temperature poisonous smoke produced by coal mine roadway fire seriously affects miners' lives and safety. Studying the development law of high-temperature smoke in the process of mine roadway fire and then exploring the danger of roadway are of great significance to personnel safety and post-disaster rescue. In order to study this problem, the CFD numerical simulation method is used to establish a fire calculation model based on ANSYS Fluent software in the development stage of mine fire. The high-temperature flue gas flow in the roadway during the development stage of mine fire is simulated, and the variation law of temperature field and gas concentration field with time and space position under different levels of roadway in the development stage of fire is revealed. The variation rules of environmental parameters, such as temperature, CO, and CO2, are obtained by numerical calculation. Based on these, the danger zones of smoke spread in fire development stage are divided by the critical values of high-temperature smoke and toxicity evaluation index, and the mathematical fitting analysis of the evolution of the dangerous area with time is carried out. The research results have certain theoretical guiding significance for reducing underground environmental pollution and ensuring the personal safety of workers and rescuers.

Performance Predication and Axial Force Study on Deep-Well Centrifugal Pump

2011 ◽  
Vol 130-134 ◽  
pp. 711-714
Author(s):  
Ling Zhou ◽  
Wei Dong Shi ◽  
Wei Gang Lu ◽  
Hui Li
Keyword(s):  
Numerical Simulation ◽  
Centrifugal Pump ◽  
Axial Force ◽  
Simulation Method ◽  
Experimental Measurements ◽  
Centrifugal Pumps ◽  
Pump Performance ◽  
Deep Well ◽  
Multi Stage ◽  
Safety And Reliability

Axial force is one of the main factors which affect the pump safety and reliability during the operation of pumps, especially in multi-stage centrifugal pumps. 150QJ20 type deep-well centrifugal pump (DCP) is selected as an example to research the pump performance and axial force with the numerical simulation and experiment method. The numerical simulation results were compared with experimental measurements, and such result was analyzed. The results show that the change trend of the pump performance and axial force acquired by numerical and experiment is similar. At rated operating point, the error of axial force between the numerical simulation and experimental measurements is less than 3%. This confirmed the feasibility of predict the pump performance by numerical simulation method.

scholarly journals An Approach to Determine Optimal Bow Configuration of Polar Ships under Combined Ice and Calm-Water Conditions

2021 ◽  
Vol 9 (6) ◽  
pp. 680
Author(s):  
Hui Li ◽  
Yan Feng ◽  
Muk Chen Ong ◽  
Xin Zhao ◽  
Li Zhou
Keyword(s):  
Numerical Simulation ◽  
Water Resistance ◽  
Numerical Technique ◽  
Experimental Studies ◽  
Resistance Index ◽  
Simulation Method ◽  
Present Approach ◽  
Calm Water ◽  
Level Ice ◽  
Ice Resistance

Selecting an optimal bow configuration is critical to the preliminary design of polar ships. This paper proposes an approach to determine the optimal bow of polar ships based on present numerical simulation and available published experimental studies. Unlike conventional methods, the present approach integrates both ice resistance and calm-water resistance with the navigating time. A numerical simulation method of an icebreaking vessel going straight ahead in level ice is developed using SPH (smoothed particle hydrodynamics) numerical technique of LS-DYNA. The present numerical results for the ice resistance in level ice are in satisfactory agreement with the available published experimental data. The bow configurations with superior icebreaking capability are obtained by analyzing the sensitivities due to the buttock angle γ, the frame angle β and the waterline angle α. The calm-water resistance is calculated using FVM (finite volume method). Finally, an overall resistance index devised from the ship resistance in ice/water weighted by their corresponding weighted navigation time is proposed. The present approach can be used for evaluating the integrated resistance performance of the polar ships operating in both a water route and ice route.

A numerical simulation method for molten material behavior in nuclear reactors

2017 ◽  
Vol 322 ◽  
pp. 301-312 ◽  
Author(s):  
Susumu Yamashita ◽  
Takuya Ina ◽  
Yasuhiro Idomura ◽  
Hiroyuki Yoshida
Keyword(s):  
Numerical Simulation ◽  
Nuclear Reactors ◽  
Simulation Method ◽  
Material Behavior ◽  
Molten Material ◽  
Numerical Simulation Method

scholarly journals Strata behavior and control strategy of backfilling collaborate with caving fully-mechanized mining

2020 ◽  
Vol 12 (1) ◽  
pp. 703-717
Author(s):  
Yin Wei ◽  
Wang Jiaqi ◽  
Bai Xiaomin ◽  
Sun Wenjie ◽  
Zhou Zheyuan
Keyword(s):  
Numerical Simulation ◽  
Control Strategy ◽  
Three Dimensional ◽  
Simulation Method ◽  
Mine Pressure ◽  
Hydraulic Support ◽  
Transition Area ◽  
Pressure Concentration ◽  
Strata Behavior ◽  
And Control

AbstractThis article analyzes the technical difficulties in full-section backfill mining and briefly introduces the technical principle and advantages of backfilling combined with caving fully mechanized mining (BCCFM). To reveal the strata behavior law of the BCCFM workface, this work establishes a three-dimensional numerical model and designs a simulation method by dynamically updating the modulus parameter of the filling body. By the analysis of numerical simulation, the following conclusions about strata behavior of the BCCFM workface were drawn. (1) The strata behavior of the BCCFM workface shows significant nonsymmetrical characteristics, and the pressure in the caving section is higher than that in the backfilling section. φ has the greatest influence on the backfilling section and the least influence on the caving section. C has a significant influence on the range of abutment pressure in the backfilling section. (2) There exits the transition area with strong mine pressure of the BCCFM workface. φ and C have significant effect on the degree of pressure concentration but little effect on the influence range of strong mine pressure in the transition area. (3) Under different conditions, the influence range of strong mine pressure is all less than 6 m. This article puts forward a control strategy of mine pressure in the transition area, which is appropriately improving the strength of the transition hydraulic support within the influence range (6 m) in the transition area according to the pressure concentration coefficient. The field measurement value of Ji15-31010 workface was consistent with numerical simulation, which verifies the reliability of control strategy of the BCCFM workface.

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