scholarly journals Comparison of Internal Flow Field between Experiment and Computation in a Radial Turbine Impeller

2004 ◽  
Vol 47 (1) ◽  
pp. 48-56 ◽  
Author(s):  
Ji DAI ◽  
Nobuaki IJICHI ◽  
Hiroshi TANGE ◽  
Hitoshi SHIBATA ◽  
Hideaki TAMAKI ◽  
...  
Keyword(s):  
Flow Field ◽  
Internal Flow ◽  
Radial Turbine ◽  
Turbine Impeller

The Effect of Partial Admission on Multistage Radial Inflow Industrial Steam Turbine

2009 ◽  
Author(s):  
Yijin Li ◽  
Qun Zheng ◽  
Lanxin Sun
Keyword(s):  
Numerical Simulation ◽  
Flow Field ◽  
Steam Turbine ◽  
Three Dimensional ◽  
Flow Patterns ◽  
Navier Stokes ◽  
Radial Turbine ◽  
Partial Admission ◽  
Aerodynamic Performances ◽  
Turbine Impeller

Aerodynamic performances of a partial admission multistage radial inflow turbine are investigated with numerical simulation. A three-dimensional unsteady Reynolds-averaged Navier–Stokes solver closed by Baldwin-Lomax model is applied for the computations. The flow field features of the first stages with partial admission are analyzed and discussed. Detailed flow patterns of the partial admission radial turbine impeller are presented here in this paper.

Numerical Study of the Internal Flow Field Characteristics in Mixed Flow Turbines

2002 ◽  
Author(s):  
D. Palfreyman ◽  
R. F. Martinez-Botas
Keyword(s):  
Flow Field ◽  
Cell Density ◽  
Numerical Study ◽  
Internal Flow ◽  
Operating Conditions ◽  
Tip Clearance ◽  
Test Facility ◽  
Meridional Plane ◽  
Mixed Flow ◽  
Radial Turbine

Presented is a numerical investigation of the characteristics of the internal flow field of a high-speed low-pressure ratio mixed flow turbine of 95.14 mm tip diameter. A commercial computational fluid dynamics (CFD) code has been successfully employed. This has been carefully validated to experimental data taken from a turbine test facility at this institution. A comparison to gated (in phase with the turbine rotation) Laser Doppler Velocimetry measurements at the turbine trailing edge and total to static efficiencies at various operating conditions, was made showing good agreement. Details of the internal flow field from a numerical study using a 393,872 cell density model are presented. These details have been compared to a radial turbine of similar geometry and performance characteristics, also analyzed using the same cell density and analysis and boundary conditions. The flow field was found to be highly three-dimensional with the tip leakage vortex as the dominant secondary flow feature. The tip clearance flow was found to be significantly influenced by the relative motion of the shroud wall, which suppressed the development of a vortex within the mainstream passage particularly in the inducer region. Comparison to the radial turbine has shown noticeable differences concentrated in the inducer region where the greater Coriolis acceleration in the radial turbine is more influential in the development of secondary flows. Considerable loss is observed localized at the blade leading edge tip region along the full length of the blade pitch; this is associated with the increased streamline curvature in the meridional plane.

Physical Quantity Synergy in the Internal Flow Field and Application in Radial-Inflow Turbines

2020 ◽  
Author(s):  
Ziyi Shao ◽  
Xuehui Zhang ◽  
Xing Wang ◽  
Yangli Zhu ◽  
Wen Li ◽  
...  
Keyword(s):  
Flow Field ◽  
Pressure Loss ◽  
Total Pressure ◽  
Internal Flow ◽  
Stream Surface ◽  
High Loss ◽  
Pressure Loss Coefficient ◽  
Radial Turbine ◽  
Total Pressure Loss Coefficient ◽  
The Relationship

Abstract The internal flow field and loss distributions are quite complicated in the radial-inflow turbine. It is necessary to reinforce physical understandings of the relationship between the flow and loss. Inspired by the synergy principle in the convective heat transfer, the synergy applicable for the radial turbine is innovatively derived from the Navier-Stokes equations. According to the mathematical expression, the smaller the synergy angle is, the higher flow resistance and loss should be. The paper attempts to assess the validation of the synergy principle in the radial turbine based on numerical simulations firstly, then the relationship between the synergy angle and loss is analyzed in detail. It is found that the regions where high total pressure loss coefficient and high dimensionless entropy generation locate correspond to the relatively small synergy angle, which agrees well with the mathematical analysis. The relatively low streamwise synergy angle corresponds to the high-loss regions near the suction side and wake on the blade-to-blade stream surface. The relatively low spanwise and circumferential synergy angle correspond to the high-loss regions near the tip clearance and wake on the span-theta stream surface. Under off-designed conditions, the synergy principle also shows great performance as an apparent negative correlation of total pressure loss coefficient versus circumferential synergy angle could be perceived.

THE INTERNAL FLOW FIELD ASSOCIATED WITH YAWED THREE-DIMENSIONAL RECTANGULAR CAVITIES

2000 ◽  
Vol 7 (3) ◽  
pp. 14
Author(s):  
Eric Savory ◽  
Norman Toy ◽  
Shiki Okamoto ◽  
Yoko Yamanishi
Keyword(s):  
Flow Field ◽  
Three Dimensional ◽  
Internal Flow

scholarly journals Influence of wall roughness on cavitation performance of centrifugal pump

2021 ◽  
Vol 43 (6) ◽  
Author(s):  
Weihui Xu ◽  
Xiaoke He ◽  
Xiao Hou ◽  
Zhihao Huang ◽  
Weishu Wang
Keyword(s):  
Flow Field ◽  
Centrifugal Pump ◽  
Internal Flow ◽  
Wall Roughness ◽  
Blade Surface ◽  
Centrifugal Pumps ◽  
Three Dimensional Model ◽  
Cavitation Inception ◽  
Cavitation Performance ◽  
Critical Cavitation

AbstractCavitation is a phenomenon that occurs easily during rotation of fluid machinery and can decrease the performance of a pump, thereby resulting in damage to flow passage components. To study the influence of wall roughness on the cavitation performance of a centrifugal pump, a three-dimensional model of internal flow field of a centrifugal pump was constructed and a numerical simulation of cavitation in the flow field was conducted with ANSYS CFX software based on the Reynolds normalization group k-epsilon turbulence model and Zwart cavitation model. The cavitation can be further divided into four stages: cavitation inception, cavitation development, critical cavitation, and fracture cavitation. Influencing laws of wall roughness of the blade surface on the cavitation performance of a centrifugal pump were analyzed. Research results demonstrate that in the design process of centrifugal pumps, decreasing the wall roughness appropriately during the cavitation development and critical cavitation is important to effectively improve the cavitation performance of pumps. Moreover, a number of nucleation sites on the blade surface increase with the increase in wall roughness, thereby expanding the low-pressure area of the blade. Research conclusions can provide theoretical references to improve cavitation performance and optimize the structural design of the pump.

scholarly journals Analysis of the Influence of Different Bionic Structures on the Noise Reduction Performance of the Centrifugal Pump

Sensors ◽  
2021 ◽  
Vol 21 (3) ◽  
pp. 886
Author(s):  
Cui Dai ◽  
Chao Guo ◽  
Yiping Chen ◽  
Liang Dong ◽  
Houlin Liu
Keyword(s):  
Flow Field ◽  
Noise Reduction ◽  
Centrifugal Pump ◽  
Great Influence ◽  
Frequency Doubling ◽  
Sound Field ◽  
Internal Flow ◽  
Test System ◽  
Centrifugal Pumps ◽  
External Characteristics

The strong noise generated during the operation of the centrifugal pump harms the pump group and people. In order to decrease the noise of the centrifugal pump, a specific speed of 117.3 of the centrifugal pump is chosen as a research object. The bionic modification of centrifugal pump blades is carried out to explore the influence of different bionic structures on the noise reduction performance of centrifugal pumps. The internal flow field and internal sound field of bionic blades are studied by numerical calculation and test methods. The test is carried out on a closed pump test platform which includes external characteristics and a flow noise test system. The effects of two different bionic structures on the external characteristics, acoustic amplitude–frequency characteristics and flow field structure of a centrifugal pump, are analyzed. The results show that the pit structure has little influence on the external characteristic parameters, while the sawtooth structure has a relatively great influence. The noise reduction effect of the pit structure is aimed at the wide-band noise, while the sawtooth structure is aimed at the discrete noise of the blade-passing frequency (BPF) and its frequency doubling. The noise reduction ability of the sawtooth structure is not suitable for high-frequency bands.

Visualization of Internal Flow Field of Propeller Fan

2017 ◽  
Author(s):  
Takaya Onishi ◽  
H. Sato ◽  
M. Hayakawa ◽  
Y. Kawata
Keyword(s):  
Flow Field ◽  
High Performance ◽  
Laser Light ◽  
Internal Flow ◽  
Light Sheet ◽  
Tip Vortex ◽  
Laser Light Sheet ◽  
Blade Surface ◽  
Similar Tendency ◽  
Flow Phenomena

Propeller fans are required not only to have high performance but also to be extremely quiet. The internal flow field of ventilation propeller fans is even more complicated because they usually have a very peculiar configuration with protruding blades upstream. Thus, many kinds of internal vortices yield which cause noise and their cause and countermeasures are needed to be clarified. The purposes of this paper are to visualize the internal flow of the propeller fan from the static and rotating frame of reference. The internal flow visualization measured from the static frame gives approximately the scale of the tip vortex. The visualization from the rotating coordinate system yields a better understanding of the flow phenomena occurring at the specific blade. The experiment is implemented by using a small camera mounted on the shaft of the fan and rotated it to capture the behavior of the vortices using a laser light sheet to irradiate the blade surface. Hence, the flow field of the specific blade could be understood to some extent. The visualized results are compared with the CFD results and these results show a similar tendency about the generation point and developing process of the tip vortex. In addition, it is found that the noise measurement result is relevant to the effect of tip vortex from the visualization result.

Research on CFD Simulation of the Cement Slurry Mixer

2012 ◽  
Vol 621 ◽  
pp. 196-199
Author(s):  
Shui Ping LI ◽  
Ya Li Yuan ◽  
Lu Gang Shi
Keyword(s):  
Flow Field ◽  
High Performance ◽  
Cfd Simulation ◽  
Structural Parameters ◽  
Internal Flow ◽  
Simulation Method ◽  
Cement Slurry ◽  
Fluid Machinery ◽  
Computational Fluid Dynamics Cfd ◽  
Machinery Design

Numerical simulation method of the internal flow field of fluid machinery has become an important technology in the study of fluid machinery design. In order to obtain a high-performance cement slurry mixer, computational fluid dynamics (CFD) techniques are used to simulate the flow field in the mixer, and the simulation results are studied. According to the analysis results, the structural parameters of the mixer are modified. The results show the mixer under the revised parameters meet the design requirements well. So CFD analysis method can shorten design period and provide valuable theoretical guidance for the design of fluid machinery.

The Influence of Wrap Angle of Blade on the Internal Flow Field and Hydraulic Performance of Double Suction Pump

2018 ◽  
Author(s):  
Hao Chang ◽  
Weidong Shi ◽  
Wei Li ◽  
Jianrui Liu ◽  
Ling Zhou ◽  
...  
Keyword(s):  
Flow Field ◽  
Cross Section ◽  
Turbulence Model ◽  
Static Pressure ◽  
Internal Flow ◽  
Hydraulic Performance ◽  
Optimal Model ◽  
Suction Pump ◽  
External Characteristic ◽  
Wrap Angle

In order to study the influence rule of wrap angle of blade on the internal flow field and hydraulic performance of double suction pump, 5 kinds of wrap angles of blade with 100°, 110°, 120°, 130° and 140° are designed in this paper. The turbulence model and the grid type are analyzed, the performance of ES350-575 double suction pump is obtained by employ the software CFX. The static pressure and velocity distributions in the cross-section are analyzed. Therefore, the optimal model is obtained, and the relevant external characteristic test is conducted. The result shows that the reasonable increase of the wrap angle of blade can enhance the performance of the pump effectively, which can improve the static pressure and velocity distributions of the internal flow field.

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