scholarly journals Numerical Simulation and Experimental Study on Flow Field in a Swirl Nozzle

2021 ◽  
Vol 2021 ◽  
pp. 1-9
Author(s):  
Yicheng Sun ◽  
Yufan Fu ◽  
Baohui Chen ◽  
Jiaxing Lu ◽  
Wanquan Deng
Keyword(s):  
Flow Field ◽  
Velocity Distribution ◽  
Flow Characteristics ◽  
Internal Flow ◽  
Low Pressure ◽  
External Flow ◽  
Droplet Velocity ◽  
Inlet Pressure ◽  
Outlet Section ◽  
Local Pressure

In order to study the internal flow characteristics and external droplet velocity distribution characteristics of the swirl nozzle, the following methods were used: numerical simulations were used to study the internal flow characteristics of a swirl nozzle and phase Doppler particle velocimetry was used to determine the corresponding external droplet velocity distribution under medium and low pressure conditions. The distributions of pressure and water velocity inside the nozzle were obtained. Meanwhile, the velocities of droplets outside the nozzle in different sections were discussed. The results show that the flow rate in the swirl nozzle increases with the increase in inlet pressure, and the local pressure in the region decreases because of the excessive velocity at the internal outlet section of the swirl nozzle, resulting in cavitation. The experimental results show that under an external flow field, the minimum droplet velocity occurs in the axial direction; starting from the axis, the velocity first increases and then decreases along the radial direction. Swirling motion inside the nozzle and velocity variations in the external flow field occur under medium and low pressure conditions. The relationship between the inlet pressure and the distributions of water droplets’ velocities was established, which provides a reference for the research and development of the swirl nozzle.

Numerical Simulation of Condenser Throat Combining with Low-Pressure Exhaust Hood for 600MW Thermal Power Unit

2012 ◽  
Vol 614-615 ◽  
pp. 77-82
Author(s):  
Jian Li ◽  
Li Zhang ◽  
Si Ping Wang
Keyword(s):  
Numerical Simulation ◽  
Flow Field ◽  
Velocity Distribution ◽  
Calculation Result ◽  
Thermal Power ◽  
Low Pressure ◽  
Exhaust Hood ◽  
Combined Model ◽  
Real Condition ◽  
Reasonable Result

In order to obtain the more real condition of the flow field at condenser throat the flow field of condenser throat is numerical simulated by the FLUENT commercial software, alone or coupling with the low-pressure exhaust hood. The results show that the flow field of condenser throat is strongly influenced by low-pressure exhaust hood, the frustum’s diffuse-angle, the low-pressure heater and the injection of the exhaust steam from the small turbine. The velocity distribution at the outlet of the throat isn’t uniform. The calculation result of combined model is also different from the single calculation result of condenser throat. Combined numerical simulation obtains more reasonable result.

Characteristic Analysis for the Internal Flow Field of CVT Torque Converter Based on FLUENT

2013 ◽  
Vol 427-429 ◽  
pp. 29-32
Author(s):  
Jin Gang Liu ◽  
Le Xiong ◽  
Yuan Qiang Tan
Keyword(s):  
Flow Field ◽  
Velocity Distribution ◽  
Channel Model ◽  
Internal Flow ◽  
Torque Converter ◽  
Characteristic Analysis ◽  
Design And Optimization ◽  
Distribution Of Flow

According to the issue of CVT torque converter internal flow field such as the complexity and not easy to calculate, the channel model of torque converter is established by UG, the grid of channel model is generated by GAMBIT, the internal flow field of torque converter is simulated based on FLUENT while the pressure and velocity distribution of flow field are calculated under three different conditions. The results show that analyzing the flow field of torque converter by FLUENT has certain guiding significance for the design and optimization of torque converter.

scholarly journals Experimental and numerical studies on the influence of inlet guide vanes of centrifugal compressor on the flow field characteristics of inlet chamber

2020 ◽  
Vol 12 (11) ◽  
pp. 168781402097490
Author(s):  
Fenghui Han ◽  
Zhe Wang ◽  
Yijun Mao ◽  
Jiajian Tan ◽  
Wenhua Li
Keyword(s):  
Centrifugal Compressor ◽  
Flow Characteristics ◽  
Internal Flow ◽  
Outlet Section ◽  
Guide Vanes ◽  
Aerodynamic Loss ◽  
Inlet Guide Vanes ◽  
Flow Parameters ◽  
Flow Field Characteristics ◽  
Flow Loss

Inlet chambers (IC) are the typical upstream component of centrifugal compressors, and inlet guide vanes in the IC have a great impact on its internal flow and aerodynamic loss, which will significantly influence the performance of the downstream compressor stages. In this paper, an experimental study was carried out on the flow characteristics inside a radial IC of an industrial centrifugal compressor, including five testing sections and 968 measuring points for two schemes with and without guide vanes. Detailed distributions of flow parameters on each section were obtained as well as the overall performance of the radial IC, and the causes of the flow loss inside the IC and the non-uniformity of flow parameters at the outlet section were investigated. Besides, numerical simulations were performed to further analyze the flow characteristics inside the radial IC. The experimental and numerical results indicate that, in the scheme without guide vanes, sudden expansions in the spiral channel and flow separations in the annular convergence channel are the major sources of flow loss and distortions generated in the radial IC; while in the scheme with guide vanes, the flow impacts, separations and wakes caused by the inappropriate design of guide vanes are the main reasons for the flow loss of the IC itself and the uneven flow distributions at the IC outlet.

Aerodynamic Simulation of Road Vehicle in Steady Crosswind

2013 ◽  
Vol 376 ◽  
pp. 341-344
Author(s):  
Shan Ling Han ◽  
Ru Xing Yu ◽  
Yu Yue Wang ◽  
Gui Shen Wang
Keyword(s):  
Flow Field ◽  
Wind Direction ◽  
Motor Vehicle ◽  
Aerodynamic Force ◽  
Flow Characteristics ◽  
Simulation Method ◽  
Aerodynamic Characteristics ◽  
External Flow ◽  
Slant Angle ◽  
Ahmed Body

Because crosswind affects drivers to control their vehicles safely, the research on flow characteristics in automotive crosswind has a great significance to improve the crosswind stability of the vehicle. By the steady state numerical simulation method, the aerodynamic characteristics of external flow field of Ahmed body in crosswind was investigated. The Ahmed body with 25° slant angle is built in UG NX. The external flow field of the Ahmed body in the wind direction of 0°, 15º, 30° angle is simulated in XFlow software. According to the map of the pressure and velocity distribution, the flow field both before and after, as well as left and right has significant change as the wind direction angle increased, and the trail turbulence intensity also changes. The changes of aerodynamic force and moment affect the driving stability of a motor vehicle.

Study of the Flow Field in Channels and Internal Manifolds on the Interconnect of a Planar Solid Oxide Fuel Cell

2005 ◽  
Author(s):  
T.-D. Chung ◽  
Y.-P. Chyou ◽  
D.-D. Yu
Keyword(s):  
Fuel Cell ◽  
Flow Field ◽  
Velocity Distribution ◽  
Solid Oxide Fuel Cell ◽  
Flow Characteristics ◽  
Solid Oxide ◽  
Oxide Fuel ◽  
Pressure Balance ◽  
Measured Velocity ◽  
Critical Measure

This research is focused on the flow characteristics in channels and internal manifolds embedded on the interconnect of a planar solid oxide fuel cell (SOFC), by implementing both numerical simulations and optical experiments. The selected commercial computational fluid dynamics (CFD) code solves the three-dimensional fluid problems with a finite volume method, while laser Doppler velocimetry (LDV) is utilized to measure the two-dimensional flow field in the channels on a hydraulic half-model. It is shown that the trend of measured velocity distribution is quite consistent with the counterpart predicted by the concurrent simulation, which serves as the mutual benchmarking process for the both approaches. Furthermore, parametric studies are carried out numerically, to reveal the insights of flow characteristics in the flow passages. The results show that pressure balance mechanisms among various channels and in-/outlet plenums turn out to be a critical measure, as far as the velocity distribution is concerned.

Analysis of Internal Flow Field for Centrifugal Fan in Series

2012 ◽  
Vol 233 ◽  
pp. 96-99
Author(s):  
Ya Jun Fan ◽  
Zhang Xu ◽  
Ding Wensi
Keyword(s):  
Velocity Distribution ◽  
Total Pressure ◽  
Flow Characteristics ◽  
Internal Flow ◽  
Wind Pressure ◽  
Meridian Plane ◽  
Centrifugal Fan ◽  
Fan Performance ◽  
In Series ◽  
The Impact

Centrifugal fan in series with high wind pressure is the key facility of pneumatic transport equipment. To consider the impact of changed conditions on performance of centrifugal fan, internal flow of three-stage centrifugal fan at rated speed in different total pressure conditions is analyzed by CFD software FLUENT6.3 in this paper. Flow characteristics are obtained and the differences of total pressure and velocity distribution in each impeller are analyzed under different conditions, velocity distribution on the meridian plane and section of wind guide plates are compared. Finally, curves of P-Q and P-η at 4600 r/min are forecasted through the analysis of the data, which provide references for reducing impact that condition alteration on fan performance and improving the efficiency of the fan.

The Three-Dimensional Unsteady Numerical Analysis of the Internal Flow Field of the New Control Valve

2014 ◽  
Vol 980 ◽  
pp. 112-116
Author(s):  
Dong Yue Qu ◽  
Jia Lei Xu ◽  
Yang Yang Huang ◽  
Xiao Zeng Xie
Keyword(s):  
Flow Field ◽  
Three Dimensional ◽  
Flow Characteristics ◽  
Control Valve ◽  
Internal Flow ◽  
Pulse Frequency ◽  
Computational Fluid Dynamics Cfd ◽  
Steam System ◽  
Normal Work ◽  
Vibration Noise

The medium flow of control valve is a typical complex unsteady flow, the internal flow is very unstable which leads to trim or body with vibration of different amplitude, therefore, control valve has been a failure-prone components in the turbine inlet steam system. This paper take the new valve as the research object, by computational fluid dynamics (CFD) software, the numerical simulation of the internal steam steady state flow field of valve normal work a typical opening in the process of opening is made, and obtain the internal flow field visualization distribution and flow characteristics of control valve. Extract unstable place pressure pulsation of the flow field, get the pulse frequency, and provide the basis for the design, optimization and application of low vibration noise control valve.

Numerical Simulation on Flow Field of Bladeless Fan

2014 ◽  
Author(s):  
Li Guoqi ◽  
Lin Peifeng ◽  
Cui Baoling ◽  
Jin Yingzi ◽  
Hu Yongjun ◽  
...  
Keyword(s):  
Numerical Simulation ◽  
Flow Field ◽  
Fluid Motion ◽  
Internal Flow ◽  
External Flow ◽  
Computational Domain ◽  
Static Characteristics ◽  
Whole Process ◽  
Velocity Magnitude ◽  
Flow Field Characteristics

With the advent of bladeless fan, technological revolutions begin to hit the industrial design world of fan. However, there is none of the developed methods on bladeless fan. To explore the excellent blowing performance of bladeless fan, numerical simulation on flow field of bladeless fan was carried out in this paper. Based on the simplified model of bladeless fan, the whole process that the airflow passes through the turbine from the inlet to the outlet slit and exit far field at last, were simulated. By comparing the flux of inlet and the flux of far outlet, the causes of flux increasing are analyzed. After analyzing static characteristics of the flow field, it shows that pressure difference is very obvious. The results obtained from velocity distribution and the characteristics of the pathlines near diffuser section and turbine, were described and analyzed. The results show that the internal flow field characteristics of bladeless fans, which we concern. The external flow field characteristics of bladeless fan was studied in the same way. And it is found that the velocity magnitude of the outlet slit and Coanda surface is much larger than other area and different positions play different roles. A general analysis on inside computational domain and outside computational domain, denotes the details about fluid motion. The research could offer reference to improvement of bladeless fan.

Flow field induced particle accumulation inside droplets in rectangular channels

Lab on a Chip ◽  
2015 ◽  
Vol 15 (13) ◽  
pp. 2879-2886 ◽  
Author(s):  
Michael Hein ◽  
Michael Moskopp ◽  
Ralf Seemann
Keyword(s):  
Flow Field ◽  
Internal Flow ◽  
Droplet Velocity ◽  
Topological Change ◽  
Particle Accumulation ◽  
Rectangular Channels

We present accumulation of sedimenting particles/cells within elongated droplets. Particle patterns evolve with droplet velocity, as explained by a topological change of the internal flow and the droplet's outer shape.

scholarly journals Analysis of Flow Field for Automotive Exhaust System Based on Computational Fluid Dynamics

2014 ◽  
Vol 8 (1) ◽  
pp. 587-593 ◽  
Author(s):  
Jianmin Xu ◽  
Shuiting Zhou
Keyword(s):  
Fluid Dynamics ◽  
Computational Fluid Dynamics ◽  
Flow Field ◽  
Pressure Loss ◽  
Engine Speed ◽  
Flow Characteristics ◽  
Exhaust System ◽  
Internal Flow ◽  
Dual Mode ◽  
Leading Role

In this study, a double mode muffler that can automatically adjust the exhaust resistance according to the engine speed was designed. Based on computational fluid dynamics theory, the governing equation and turbulent equations for numerical simulation of muffler were established. The pressure loss and the internal flow characteristics of the double mode muffler were analyzed by CFD software. The influence of the distance between the main and submuffler on the flow field of exhaust system was researched. In addition, the internal pressure distribution, the turbulence intensity distribution and the velocity vector diagram of the dual mode muffler were also obtained. The pressure loss of double mode muffler is mainly distributed in the area of air mutations. Main silencer plays a leading role in the entire exhaust system. Therefore, the trend of the pressure loss of the exhaust system with the change in the distance between main and auxiliary muffler was also obtained. When the distance between the main and auxiliary silencer changed from 50 mm to 300 mm, the pressure loss of exhaust system muffler first increased and then decreased, and following this, continued to increase. The results will provide a theoretical basis for designing complex exhaust system.

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