Velocity Mapping Procedures for Tidal Stream Turbines in an Arbitrary Flow Field and the Implications on Performance Due to Non-Uniform Flow

2009 ◽  
Author(s):  
J. Chapman ◽  
J.A.C. Orme ◽  
I. Masters
Keyword(s):  
Flow Field ◽  
Uniform Flow ◽  
Velocity Mapping ◽  
Tidal Stream ◽  
Arbitrary Flow

scholarly journals Numerical simulation of the non-uniform flow in a full-annulus multi-stage axial compressor with the harmonic balance method

2020 ◽  
Vol 12 (3) ◽  
pp. 168781401989721 ◽  
Author(s):  
Haiou Sun ◽  
Meng Wang ◽  
Zhongyi Wang ◽  
Song Wang ◽  
Franco Magagnato
Keyword(s):  
Flow Field ◽  
Harmonic Balance ◽  
Axial Compressor ◽  
Harmonic Balance Method ◽  
Internal Flow ◽  
Uniform Flow ◽  
Experimental Results ◽  
Balance Method ◽  
Operating Characteristics ◽  
Multi Stage

To improve the understanding of unsteady flow in modern advanced axial compressor, unsteady simulations on full-annulus multi-stage axial compressor are carried out with the harmonic balance method. Since the internal flow in turbomachinery is naturally periodic, the harmonic balance method can be used to reduce the computational cost. In order to verify the accuracy of the harmonic balance method, the numerical results are first compared with the experimental results. The results show that the internal flow field and the operating characteristics of the multi-stage axial compressor obtained by the harmonic balance method coincide with the experimental results with the relative error in the range of 3%. Through the analysis of the internal flow field of the axial compressor, it can be found that the airflow in the clearance of adjacent blade rows gradually changes from axisymmetric to non-axisymmetric and then returns to almost completely axisymmetric distribution before the downstream blade inlet, with only a slight non-axisymmetric distribution, which can be ignored. Moreover, the slight non-axisymmetric distribution will continue to accumulate with the development of the flow and, finally, form a distinct circumferential non-uniform flow field in latter stages, which may be the reason why the traditional single-passage numerical method will cause certain errors in multi-stage axial compressor simulations.

Average Flow Inside and Around Fish Cages With and Without Fouling in a Uniform Flow

2010 ◽  
Author(s):  
Lars Gansel ◽  
Thomas A. McClimans ◽  
Dag Myrhaug
Keyword(s):  
Flow Field ◽  
Numerical Models ◽  
Fish Farming ◽  
Reynolds Numbers ◽  
Uniform Flow ◽  
Metal Mesh ◽  
Average Flow ◽  
Fish Cages ◽  
Farming Industry ◽  
Porous Cylinders

The average flow field inside and around the bottom of porous cylinders in a uniform flow is explored using Particle Image Velocimetry (PIV). Tests were conducted on six cylinders with porosities of 0%, 30%, 60%, 75%, 82% and 90% in a flume tank where the flow field inside and around the models is time averaged over 180 seconds. The models had a height-to-diameter ratio of 3 and were made from metal mesh. The Reynolds numbers ranged from 5,000 to 20,000 based on the diameter of the models and from 75 to 300 based on the diameter of individual strands of the mesh, which corresponds to the Reynolds numbers occurring at salmon fish cage netting used along the Norwegian coast. The porosities of 82%, 75% and 60% correspond to those of a fish cage netting in Norwegian Salmon farming with no, light and heavy biofouling, respectively. The results from this study are discussed with respect to the instantaneous flow field in and around the same cylinders at identical Reynolds numbers. The focus is on the effect of porosity on the ventilation inside the cages and the vertical transports within the near wake. It is shown that heavy fouling of aquacultural nettings can lead to internal circulation inside fish cages and therefore has the potential to reduce the ventilation of the net pens dramatically. The description of the time-averaged flow field inside and around porous cylinders can be used as benchmarks to validate and adjust numerical models of the flow past porous cylinders. The results from this study can be valuable also for the fish farming industry, as bio-fouling and the reduced porosity of fish cages can be monitored and controlled directly by fish farmers.

Uniform Flow Field Design in Porous Media Filter Tower and Experimental Verification

2021 ◽  
Author(s):  
Hanling Mao ◽  
Siyue Li ◽  
Shun Lan ◽  
Shanshan Guo ◽  
Yuefeng Huang ◽  
...  
Keyword(s):  
Porous Media ◽  
Flow Field ◽  
Experimental Verification ◽  
Uniform Flow ◽  
Flow Field Design

scholarly journals Electrotaxis of oral squamous cell carcinoma cells in a multiple-electric-field chip with uniform flow field

2012 ◽  
Vol 6 (3) ◽  
pp. 034116 ◽  
Author(s):  
Hsieh-Fu Tsai ◽  
Shih-Wei Peng ◽  
Chun-Ying Wu ◽  
Hui-Fang Chang ◽  
Ji-Yen Cheng
Keyword(s):  
Squamous Cell Carcinoma ◽  
Oral Squamous Cell Carcinoma ◽  
Flow Field ◽  
Electric Field ◽  
Cell Carcinoma ◽  
Squamous Cell ◽  
Uniform Flow ◽  
Carcinoma Cells

scholarly journals Screening model for the contamination of a well in a uniform flow field

1999 ◽  
Vol 35 (9) ◽  
pp. 2871-2875 ◽  
Author(s):  
Christopher Kennedy ◽  
William C. Lennox
Keyword(s):  
Flow Field ◽  
Uniform Flow ◽  
Screening Model

scholarly journals Wake Region Measurements of a Highly Three-Dimensional Nozzle Guide Vane Tested at DRA Pyestock Using Particle Image Velocimetry

1994 ◽  
Author(s):  
M. Funes-Gallanzi ◽  
P. J. Bryanston-Cross ◽  
K. S. Chana
Keyword(s):  
Flow Field ◽  
High Speed ◽  
Guide Vane ◽  
Three Dimensional ◽  
Light Sheet ◽  
Test Facility ◽  
Velocity Mapping ◽  
Nozzle Guide Vane ◽  
Nozzle Guide ◽  
Annular Cascade

The quantitative whole field flow visualization technique of PIV has over the last few years been successfully demonstrated for transonic flow applications. A series of such measurements has been made at DRA Pyestock. Several of the development stages critical to a full engine application of the work have now been achieved using the Isentropic Light Piston Cascade (ILPC) test facility operating with high inlet turbulence levels: • A method of seeding the flow with 0.5μm diameter styrene particles has provided an even coverage of the flow field. • A method of projecting a 1 mm thick high power Nd/YAG laser light sheet within the turbine stator cascade. This has enabled a complete instantaneous intra-blade velocity mapping of the flow field to be visualized, by a specially developed diffraction-limited optics arrangement. • Software has been developed to automatically analyze the data. Due to the sparse nature of the data obtained, a spatial approach to the extraction of the velocity vector data was employed. • Finally, a comparison of the experimental results with those obtained from a three-dimensional viscous flow program of Dawes; using the Baldwin-Lomax model for eddy viscosity and assuming fully turbulent flow. The measurements provide an instantaneous quantitative whole field visualization of a high-speed unsteady region of flow in a highly three-dimensional nozzle guide vane; which has been successfully compared with a full viscous calculation. This work represents the first such measurements to be made in a full-size transonic annular cascade at engine representative conditions.

Droplet Dynamics in a Non-uniform Flow Field

1991 ◽  
Vol 80 (4-6) ◽  
pp. 319-335 ◽  
Author(s):  
G. T. LINTERIS ◽  
P. A. LIBBY ◽  
F. A. WILLIAMS
Keyword(s):  
Flow Field ◽  
Uniform Flow ◽  
Droplet Dynamics

scholarly journals Drag on two coaxial, nonuniformly structured flocs in a uniform flow field

2005 ◽  
Vol 292 (1) ◽  
pp. 290-298 ◽  
Author(s):  
Jyh-Ping Hsu ◽  
Shu-Jen Yeh ◽  
Duu-Jong Lee
Keyword(s):  
Flow Field ◽  
Uniform Flow
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