scholarly journals Numerical Simulation of Internal Flow Field in Turbo-Expander

2021 ◽  
Vol 2137 (1) ◽  
pp. 012073
Author(s):  
Chaojie Li ◽  
Yanqin Mao ◽  
Xiaoyue Wang ◽  
Zhixing Zhan ◽  
Liang Cai
Keyword(s):  
Numerical Simulation ◽  
Power Generation ◽  
Flow Direction ◽  
Internal Flow ◽  
Inlet Pipe ◽  
Centrifugal Effect ◽  
Impeller Outlet ◽  
Turbo Expander ◽  
Simulation Results ◽  
Flow Vortex

Abstract As everyone pays more attention to energy consumption, it is very meaningful to use natural gas pressure energy for power generation and turbo-expander is an important part of power generation devices. In this paper, the turbo-expander model for pressure energy generation is meshed and numerically simulated based on fluent, and the pressure distribution and velocity distribution in the turbo-expander are obtained. The volute profile is Archimedes spiral, and the impeller is modeled by cfturbo. The main conclusions are as follows: when the number of grids is more than 2.2 million, the simulation results are less affected by the number of grids. The internal basin of the turbo-expander has obvious pressure gradient and velocity gradient. Due to the negative pressure at the elbow of the inlet pipe of the centrifugal effect, the existence of the blade leads to the change of the flow direction. Different watershed planes have different pressure and velocity distributions. The velocity and pressure of the watershed plane near the impeller outlet and the volute outlet are often smaller, but the flow vortex is more intense.

Research on Characteristics of Flow Field Inside Tangential Inlet Cyclone Separator

2012 ◽  
Author(s):  
Yigang Luan ◽  
Pengfei Liu ◽  
Haiou Sun ◽  
Yulin Deng
Keyword(s):  
Numerical Simulation ◽  
Flow Field ◽  
Empirical Formula ◽  
Research Result ◽  
Internal Flow ◽  
Cyclone Separator ◽  
Resistance Characteristic ◽  
Simulation Results ◽  
Tangential Inlet ◽  
Simulation Scheme

Flow field inside tangential cyclone separator is a kind of complex three-dimensional rotation turbulent flow. To optimize the flow field structure and shorten the cycle of research and development, it is essential to find an appropriate calculation method to predict the flow field inside cyclone separators. In the article, FLUENT software is employed to obtain the internal flow field of tangential inlet cyclone separator by adopting different calculation models and different numerical simulation scheme. Also the simulation result was compared with that of existing experiment data to find a reasonable solution for the simulation of the flow field characteristics inside the cyclone. After the examination to the rationality of the different numerical simulation method, and the comparative analysis in the main flow field parameters of the simulated results which is the most reasonable combination, the flow characteristics of internal flow field of tangential inlet cyclone separator was obtained. The results show that: when the grid number of calculation domain reach 860000, it can cater to the calculation conditions of flow field, and the simulation results can agree with the experimental data better and will hardly change with the grid number; On the basis of standard k-ε model, the numerical simulation scheme was formulated by the orthogonal experiment method, through the comparison of results, the best combinations are 2 and 11; Applying the optimized combination to RNG k-ε model, Realizable k-ε model and RSM model and comparing simulation results with the existing one show that RSM was the ideal model used in simulation; With the change of the flow rate came a resistance characteristic curve of cyclone separator. The comparison between it and the predicted results of existing empirical formula of resistance characteristic drew the numerical simulation result, which is closest to Dirgo empirical formula; the first and second order upwind form have certain influence on the numerical simulation results, but the second one is more accurate in terms of simulating and predicting the parameters distribution inside flow field. This research result has certain reference value for cyclone separator design and performance optimization.

Numerical Simulation of Internal Flow Field in Mixed Flow Fan

2013 ◽  
Vol 860-863 ◽  
pp. 1589-1593
Author(s):  
Yan Zhao Zhai ◽  
Hong Ming Zhang
Keyword(s):  
Numerical Simulation ◽  
Flow Field ◽  
Velocity Distribution ◽  
Pressure Distribution ◽  
Three Dimensional ◽  
Internal Flow ◽  
Field Structure ◽  
Mixed Flow ◽  
Flow Phenomenon ◽  
Impeller Outlet

The numerical simulation of internal flow field of a mixed-flow fan was carried out on the star-CD platform. Three-dimensional steady turbulent flow is calculated using the standard k-ɛ turbulence model, and the pressure distribution, velocity distribution and other important flow phenomenon inside the fan are obtained. The number of meshes has important influence on the result, meanwhile, fan inlet, impeller, outlet interact with each other. The results of numerical simulation can accurately analyze the fan flow field. The results of numerical simulation can accurately analyze the fan flow field structure, and provide guidance for further optimization and improvement of the fan.

Modeling and Simulation of a Stand-Alone Hydrogen Photovoltaic Fuel Cell Hybrid System

2014 ◽  
pp. 829-859
Author(s):  
M.T. Benmessaoud ◽  
A. Boudghene Stambouli ◽  
M. Tioursi
Keyword(s):  
Numerical Simulation ◽  
Mathematical Model ◽  
Power Generation ◽  
High Temperature ◽  
Fuel Cell ◽  
Hydrogen Generation ◽  
Storage System ◽  
Storage Unit ◽  
Pv Array ◽  
Simulation Results

In this Chapter, a hybrid Photovoltaic-Fuel Cell (PV-FC) generation system employing an electrolyser for hydrogen generation is designed and simulated. The system is applicable for remote areas or isolated loads. This system has been simulated via a developed general dynamic mathematical model which analytically describes the electric subsystems. Some interesting simulation results are presented in this chapter. Specific attention is paid to the investigation of the dynamic analysis of the photovoltaic, fuel cell, and electrolyser system at the connection. The objective of this study is to evaluate the performance of an autonomous stationary power generation and thermal coupling a PV array and a storage system for hydrogen, consisting of an electrolyser, a storage unit of gas, and a fuel cell of high temperature. Hydrogen is the only means that stores electricity. Stationary applications of a few kilowatts are evaluated by numerical simulation in MATLAB/SIMULINK.

A High-Loaded Supersonic Axial Compressor Aerodynamic Design Principle

2012 ◽  
Author(s):  
Yingjiao Hu ◽  
Songtao Wang
Keyword(s):  
Numerical Simulation ◽  
Design Principle ◽  
High Efficiency ◽  
Pressure Ratio ◽  
Flow Characteristics ◽  
Axial Compressor ◽  
Axial Flow ◽  
Internal Flow ◽  
Aerodynamic Design ◽  
Simulation Results

Reviewed the historical development of the supersonic axial flow compressor, and gave an outlook for its future developments and research orientations. According to the internal flow characteristics of the conventional supersonic axial flow compressors, put forward a high load of supersonic axial compressor aerodynamic design principle. A preliminary design verification of the principle has been carried. The 3D viscous numerical simulation results show that, under the tip tangential speed 360m / s, has achieved a stage pressure ratio 2.3 with efficiency 86.5%. In addition, considering the rotor under impulse condition can get the maximum rotor total pressure ratio with high efficiency, a design principle has also been put forward to solve the high entrance Mach number problem of the downstream stator. But the numerical simulation results show that the multi-shock structure does not have any advantages to reduce the stator losses.

Simulation and Analysis the Internal Flow Field of Control Valve Bonnet Leakage

2013 ◽  
Vol 423-426 ◽  
pp. 2078-2081 ◽  
Author(s):  
Yan Tao An ◽  
Ru Jian Ma ◽  
Yong Wang
Keyword(s):  
Numerical Simulation ◽  
Flow Field ◽  
Flow Direction ◽  
Control Valve ◽  
Internal Flow ◽  
Surrounding Area ◽  
Valve Body ◽  
Outlet Flow ◽  
Cfd Numerical Simulation

Apply the CFD numerical simulation the internal flow field and noise when the control valve is bonnet leakage and trouble-free. Research shows that bonnet leaking has almost no effect on valve inlet and outlet flow field. It is an impact on valve body flow field and the greatest impact on balance cavity. It changes the flow direction of the balance cavity and produces right vortex, in balance cavity where originally without noise, the tremendous noise appeares and improves the noise of the surrounding area.

Modeling and Simulation of a Stand-Alone Hydrogen Photovoltaic Fuel Cell Hybrid System

2017 ◽  
pp. 545-580 ◽  
Author(s):  
M.T. Benmessaoud ◽  
A. Boudghene Stambouli ◽  
M. Tioursi
Keyword(s):  
Numerical Simulation ◽  
Mathematical Model ◽  
Power Generation ◽  
High Temperature ◽  
Fuel Cell ◽  
Hydrogen Generation ◽  
Storage System ◽  
Storage Unit ◽  
Pv Array ◽  
Simulation Results

In this Chapter, a hybrid Photovoltaic-Fuel Cell (PV-FC) generation system employing an electrolyser for hydrogen generation is designed and simulated. The system is applicable for remote areas or isolated loads. This system has been simulated via a developed general dynamic mathematical model which analytically describes the electric subsystems. Some interesting simulation results are presented in this chapter. Specific attention is paid to the investigation of the dynamic analysis of the photovoltaic, fuel cell, and electrolyser system at the connection. The objective of this study is to evaluate the performance of an autonomous stationary power generation and thermal coupling a PV array and a storage system for hydrogen, consisting of an electrolyser, a storage unit of gas, and a fuel cell of high temperature. Hydrogen is the only means that stores electricity. Stationary applications of a few kilowatts are evaluated by numerical simulation in MATLAB/SIMULINK.

Avalanche Features in Silicon Schottky-FETs in Accordance with Numerical Simulation Results

2006 ◽  
Vol 65 (16) ◽  
pp. 1533-1546
Author(s):  
Yu. Ye. Gordienko ◽  
S. A. Zuev ◽  
V. V. Starostenko ◽  
V. Yu. Tereshchenko ◽  
A. A. Shadrin
Keyword(s):  
Numerical Simulation ◽  
Simulation Results

Tail shapes lead to different propulsive mechanisms in the body/caudal fin undulation of fish

2020 ◽  
pp. 095440622096768
Author(s):  
Jialei Song ◽  
Yong Zhong ◽  
Ruxu Du ◽  
Ling Yin ◽  
Yang Ding
Keyword(s):  
Numerical Simulation ◽  
Aspect Ratio ◽  
High Efficiency ◽  
The Body ◽  
Caudal Fin ◽  
Fish Model ◽  
Swimming Efficiency ◽  
Simulation Results ◽  
Propulsive Mechanism ◽  
High Depth

In this paper, we investigate the hydrodynamics of swimmers with three caudal fins: a round one corresponding to snakehead fish ( Channidae), an indented one corresponding to saithe ( Pollachius virens), and a lunate one corresponding to tuna ( Thunnus thynnus). A direct numerical simulation (DNS) approach with a self-propelled fish model was adopted. The simulation results show that the caudal fin transitions from a pushing/suction combined propulsive mechanism to a suction-dominated propulsive mechanism with increasing aspect ratio ( AR). Interestingly, different from a previous finding that suction-based propulsion leads to high efficiency in animal swimming, this study shows that the utilization of suction-based propulsion by a high- AR caudal fin reduces swimming efficiency. Therefore, the suction-based propulsive mechanism does not necessarily lead to high efficiency, while other factors might play a role. Further analysis shows that the large lateral momentum transferred to the flow due to the high depth of the high- AR caudal fin leads to the lowest efficiency despite the most significant suction.

scholarly journals Increasing the efficiency of using the natural gas potential energy in turbo-expander units for power generation

2021 ◽  
Author(s):  
Sergey Osipov ◽  
Olga Zlyvko ◽  
Nikolay Bychkov ◽  
Daria Kharlamova ◽  
Arkadiy Zaryankin
Keyword(s):  
Power Generation ◽  
Natural Gas ◽  
Potential Energy ◽  
Turbo Expander ◽  
Gas Potential

scholarly journals Experiment and simulation about the effect of wear-ring abrasion on the performance of a marine centrifugal pump

2021 ◽  
Vol 13 (2) ◽  
pp. 168781402199811
Author(s):  
Wu Xianfang ◽  
Du Xinlai ◽  
Tan Minggao ◽  
Liu Houlin
Keyword(s):  
Numerical Simulation ◽  
Centrifugal Pump ◽  
Pressure Pulsation ◽  
Vibration Velocity ◽  
Test Results ◽  
Obvious Effect ◽  
Performance Change ◽  
Pump Test ◽  
Simulation Results ◽  
Axis Passing

The wear-ring abrasion can cause performance degradation of the marine centrifugal pump. In order to study the effect of front and back wear-ring clearance on a pump, test and numerical simulation were used to investigate the performance change of a pump. The test results show that the head and efficiency of pump decrease by 3.56% and 9.62% respectively at 1.0 Qd due to the wear-ring abrasion. Under 1.0 Qd, with the increase of the front wear-ring the vibration velocity at pump foot increases from 0.4 mm/s to 1.0 mm/s. The axis passing frequency (APF) at the measuring points increases significantly and there appears new characteristic frequency of 3APF and 4APF. The numerical simulation results show that the front wear-ring abrasion affects the flow at the inlet of the front chamber of the pump and impeller passage. And the back wear-ring abrasion has obvious effect on the flow in the back chamber of the pump and impeller passage, while the multi-malfunction of the front wear-ring abrasion and back wear-ring abrasion has the most obvious effect on the flow velocity and flow stability inside pump. The pressure pulsation at Blade Passing Frequency (BPF) of the three schemes all decrease with the increase of the clearance.

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