Numerical Investigation on Unsteady Characteristics in Different Rim Seal Geometries: Part A

2020 ◽  
Author(s):  
Xie Lei ◽  
Wang RuoNan ◽  
Liu Guang ◽  
Lian ZengYan ◽  
Du Qiang
Keyword(s):  
Numerical Simulation ◽  
Flow Field ◽  
Pressure Distribution ◽  
Engine Efficiency ◽  
Ansys Cfx ◽  
Geometry Configuration ◽  
Numerical Simulation Methods ◽  
Unsteady Simulation ◽  
Unsteady Characteristics ◽  
Cooling Air

Abstract Secondary sealing flow is of great importance in the turbine disk cooling and sealing system. The amount of cooling air extracted from the compressor is crucial to engine efficiency. To determine a minimum amount of cooling air, the flow characteristic of the rim seal should be investigated. Numerical simulation is carried out to investigate the flow field near the rim seal region. Both RANS and URANS numerical simulation methods are used in the commercial CFD code ANSYS CFX to analyze axial and radial rim seals. In the simulation, a 1/33 sector is selected as computing region to simulate the flow field and the SST turbulent model is used. The steady and unsteady simulation results of pressure distribution and seal efficiency are analyzed and compared. The computed results show that due to the different geometry configuration, the pressure distribution also shows inconsistency. Unsteady phenomena are observed in both axial and radial type of rim seals. Radial sealing lip can suppress the inherent unsteadiness and interaction between main flow and sealing flow, thus showing higher sealing efficiency. Comparing to steady results using the RANS method; unsteady simulation, using the URANS method, can capture the pressure difference and seal efficiency fluctuation at the disk rim more efficiently. Also, the interaction between the rotor and stator is considered in unsteady simulation, so the unsteady simulation is recommended. The results obtained in the current paper are useful to the investigation and design of turbine rim seals.

Effect of Turbulence Parameters on Numerical Simulation of Complex Automotive External Flow Field

2011 ◽  
Vol 52-54 ◽  
pp. 1062-1067 ◽  
Author(s):  
Xing Jun Hu ◽  
Peng Qin ◽  
Peng Guo ◽  
Yang An
Keyword(s):  
Numerical Simulation ◽  
Flow Field ◽  
Numerical Simulations ◽  
Drag Coefficient ◽  
Pressure Distribution ◽  
Viscosity Ratio ◽  
External Flow ◽  
Length Scale ◽  
Slant Angle ◽  
Turbulence Parameters

Numerical simulations for the Ahmed model with 25° slant angle are performed under three different turbulent parameters, intensity and length scale, intensity and viscosity ratio, k and epsilon. The external flow field of ahmed model with 25° slant angle is got, and all the velocity vectors, pressure distribution and the drag coefficient of the flow field are obtained as well. The comparison between the numerical simulations and the experimental statistics shows that intensity and viscosity and k and epsilon characterized by higher computation accuracy are more suitable for numerical simulation of automotive external flow field.

Numerical Simulation of Atmospheric Flow Field around Bridge

2013 ◽  
Vol 368-370 ◽  
pp. 1379-1382
Author(s):  
Ying Jia ◽  
Li Zhang ◽  
Sheng Zhang
Keyword(s):  
Numerical Simulation ◽  
Flow Field ◽  
Pressure Distribution ◽  
Cross Section ◽  
Horizontal Plane ◽  
Atmospheric Flow ◽  
Airflow Field ◽  
Distribution Laws ◽  
The Cross

This paper carries out a numerical simulation of the atmospheric flow field around bridge. The variation law of airflow field around bridge is studied. Velocity and pressure distribution laws of flow field in horizontal plane and the cross-section are discussed, and influence range of flow field around bridge area is identified.

Study of Truck’s Aerodynamic Drag Reduction Based on Jet

2014 ◽  
Vol 635-637 ◽  
pp. 316-319
Author(s):  
Peng Guo ◽  
Jun Yuan Zhang ◽  
Qi Fei Li ◽  
Xing Jun Hu
Keyword(s):  
Numerical Simulation ◽  
Comparative Analysis ◽  
Flow Field ◽  
Drag Reduction ◽  
Pressure Distribution ◽  
Aerodynamic Drag ◽  
Outer Flow ◽  
Air Movement ◽  
Maximum Drag Reduction ◽  
Aerodynamic Drag Reduction

Multiple schemes are adapted on truck's outer flow field based on numerical simulation. Comparative analysis with the state of air flow, the pressure distribution, the air movement between the cab and cargo is pursued, then obtain the effect of jet flow velocity to the truck Cd. With the increasing of the jet velocity, Cd increases first and then decreases. The maximum drag reduction can reaches 7.38%.

A CFD Method Study on the Resistance Performance of the Axial Flow Cyclone Separator

2017 ◽  
Author(s):  
Yigang Luan ◽  
Lianfeng Yang ◽  
Tao Sun
Keyword(s):  
Numerical Simulation ◽  
Flow Field ◽  
Axial Flow ◽  
Internal Flow ◽  
Operating Pressure ◽  
Cyclone Separator ◽  
Axial Flow Cyclone ◽  
Flow Field Characteristics ◽  
Numerical Simulation Methods ◽  
Resistance Performance

Axial flow cyclone separator with guide blade has been widely used, due to its low resistance, huge gas processing and small volume. Although its structure is simple, three-dimension strong rotating turbulent flow forms which involves many complex interactions such as dual-phase separation, adsorption and electrostatic interference. This paper is focused on studying the resistance performance of the axial flow cyclone separator. Numerical simulation methods are carried out to acquire the internal flow field characteristics under different operating pressure and temperature conditions. The result shows that the pressure drop decreases under the same operating pressure, as the operating temperature increases. When the operating temperature is the same, the higher operating pressure enhances the value of the pressure drop. Velocity distribution, pressure contours and turbulent viscosity contours have been presented, to analyze the characteristics of the internal airflow, so as to help optimize the design. Experiments are intended to verify the results of numerical simulation and explore the internal flow field of the cyclone separator further. The cyclone separator has 8 rotary blades which are split into 8 parts, namely one blade is 45° in the tangential direction. 0° and 22.5° are chosen in the experiment. The dimensionless pressure distribution is shown. A comparison of the CFD results and the experimental results is made to prove that the numerical simulation methods are correct and accurate. The curve of the numerical simulation results is very close to that of the experimental results with the similar trend. It is concluded that the methods can predict the internal flow field characteristics of the axial flow cyclone separator.

Numerical Simulation on Flow Field of Screen Filter for Drip Irrigation in Field

2012 ◽  
Vol 212-213 ◽  
pp. 1197-1200 ◽  
Author(s):  
Quan Li Zong ◽  
Tie Gand Zheng
Keyword(s):  
Numerical Simulation ◽  
Flow Field ◽  
Velocity Distribution ◽  
Pressure Distribution ◽  
Drip Irrigation ◽  
Radial Direction ◽  
Turbulent Energy ◽  
Head Loss ◽  
Turbulent Pressure ◽  
High Turbulence

Based on CFD software Fluent, the flow field of screen filter was simulated numerically，and the results of calculation were analyzed in detailed. The results show that the velocity distribution declines along the radial direction of tank. The flow can be rotated and mixed in tank, and the screen of outlet can be clogged quickly resulting in uneven clogging. The turbulent pressure distribution of filter is not uniformity. In the inlet, the turbulent energy is larger than the second tank. In the inlet of second screen, there is a high turbulence region resulting in the larger head loss. The pressure distribution of the second tank is uniformity in the course of filter work. However, the pressure of the first tank is significantly higher than the second one.

Numerical Optimization of Oilfield Heating Furnace Research

2013 ◽  
Vol 805-806 ◽  
pp. 1874-1877
Author(s):  
Jie Nan Dong ◽  
Xu Su ◽  
Tong Chen ◽  
Miao Wang ◽  
Xiao Xu Li
Keyword(s):  
Numerical Simulation ◽  
Temperature Distribution ◽  
Flow Field ◽  
Internal Flow ◽  
Heating Furnace ◽  
Oil Field ◽  
Simulation Tools ◽  
Flow Field Characteristics ◽  
Numerical Simulation Methods ◽  
Physical And Chemical

In this paper,using numerical simulation tools PHOENICS for numerical simulation study is made on furnace gas burning in the hearth, and analyses furnace oil furnace temperature distribution in the flow field characteristics the internal flow field of oil field heating furnace hearth temperature distribution characteristics. On this basis, this paper establisheda mathematical model which can truly describe the chamber internal physical and chemical changes, selected the appropriate numerical simulation methods, plotted the actual temperature profile case, which can reflect the qualitative and quantitative actual situation of work.Finally suggestions are given, which provides the theoretical foundation for the next step and the actual research.

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.

Blade Curve Influences on Performance of Savonius Rotors: Experimental and Numerical

2010 ◽  
Author(s):  
Ali Kianifar ◽  
Morteza Anbarsooz ◽  
Mohammad Javadi
Keyword(s):  
Numerical Simulation ◽  
Reynolds Number ◽  
Wind Tunnel ◽  
Flow Field ◽  
Pressure Distribution ◽  
Power Coefficient ◽  
Blade Surface ◽  
Wind Tunnel Tests ◽  
Savonius Rotor ◽  
Circular Curves

In this study, the effect of blade curve on the power coefficient of a Savonius rotor is investigated by means of numerical simulation and wind tunnel tests. The tests were conducted on six rotors with identical dimensions but different blade curves, and the influences of blade curve and Reynolds number were studied. Followed by a simulation of the flow field around rotors with identical semi-circular curves and different overlaps, torque was calculated using pressure distribution on the blade surface, and the effect of Reynolds number and blade curve were studied on torque as well. Results indicate that changing the blade curve affects the power coefficient and torque by causing different drag coefficients. Also the rotor that yields the highest power coefficient and torque in one revolution compared with other rotors is highlighted.

Numerical Simulation of 3D Flow Field Structure in Turbine Cascade With Bowed Blades

2001 ◽  
Author(s):  
Songtao Wang ◽  
Zhongqi Wang ◽  
Guotai Feng
Keyword(s):  
Numerical Simulation ◽  
Flow Field ◽  
Pressure Gradient ◽  
Pressure Distribution ◽  
Great Influence ◽  
Horseshoe Vortex ◽  
Suction Surface ◽  
Blade Cascade ◽  
Passage Vortex ◽  
Type Pressure

The differences of flow field in bowed blade cascade and that in straight blade cascade are systematically studied in this paper. To bow a blade means to change its geometric boundary condition. This change not only affect the pressure distribution along the blade profile exit Mach number but also has great effect on the original position and development of the passage vertex. All of the changes mentioned above have great influence on the loss. Numerical simulation result showed that blade bowing can decrease the cross-pressure gradient near the end wall. This trend will be more obvious with the increase of the bow angle. The pressure gradient decrease is beneficial to weaken the passage vortex strength and reduces the secondary loss near the endwalls. In addition, Pressure gradient from endwalls to midspan can be established near suction surface in positively bowed blade. With the increase of bow angle, this C-type pressure distribution is remarkable. It is also found that this C-type pressure distribution will influence the position of corner vortex near the suction surface and will also influence the position and size of the passage vortex. Blade bowing also has great influence on the position of the saddle point near the leading edge and the separated line of the horseshoe vortex. It is found that the position of the saddle point and the separated line of both legs of the horseshoe vortex move forward in a positively bowed blade. The passage vortex structure in bowed cascade is also presented. It can be concluded that a bowed blade can make the passage vortex stable and helps change its structure from loose to compact. Blade bowing is also beneficial to limit the influence domain of the unstable passage vortex core by the stable limit cycle.

scholarly journals Experimental and Numerical Investigation of Pressure Fluctuation in a Low-Specific-Speed Centrifugal Pump with a Gap Drainage Impeller

2021 ◽  
Vol 2021 ◽  
pp. 1-14
Author(s):  
Li Zhang ◽  
Hui Li ◽  
Hong Xu ◽  
Weidong Shi ◽  
Yang Yang ◽  
...  
Keyword(s):  
Numerical Simulation ◽  
Flow Field ◽  
Pressure Pulsation ◽  
Internal Flow ◽  
Stable Operation ◽  
Simulation Methods ◽  
Centrifugal Pumps ◽  
Numerical Simulation Methods ◽  
Low Specific Speed ◽  
Specific Speed

In order to analyze the effect of impeller with different slot widths on the performance of the low-specific-speed centrifugal pumps, based on the impeller of a single-stage pump with the specific speed of 21, two gap drainage schemes with slot widths of 1.5 mm and 6.0 mm, slot diameter of 180 mm, and lap length of 5 mm were designed. Both experimental and numerical simulation methods were applied to compare the steady performance, which includes the head, efficiency, and the internal flow field distribution, and the unsteady pressure pulsation performance between new designed pumps and the original pump. The results show that gap drainage would cause a certain degree of head reduction, but a smaller slot width could achieve higher efficiency. Meanwhile, a reasonable open seam scheme can reduce the development of pressure pulsation, which provides experience and reference for the stable operation of low-specific-speed centrifugal pumps.

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