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Start Over Subject velocity distribution

1. Analysis of in situ water velocity distributions in the lowland river floodplain covered by grassland and reed marsh habitats - a case study of the bypass channel of Warta River (Western Poland)

Creator:
Laks, Ireneusz, Szoszkiewicz, Krzysztof, and Kałuża, Tomasz
Type:
article, model:article, and TEXT
Subject:
floodplain vegetation, flow resistance, in situ measurements, and velocity distribution
Language:
Slovak
Description:
The analysis of in situ measurements of velocity distribution in the floodplain of the lowland river has been carried out. The survey area was located on a bypass channel of the Warta River (West of Poland) which is filled with water only in case of flood waves. The floodplain is covered by grassland and reed marsh habitats. The velocity measurements were performed with an acoustic Doppler current profiler (ADCP) in a cross-section with a bed reinforced with concrete slabs. The measured velocities have reflected the differentiated impact of various vegetation types on the loss of water flow energy. The statistical analyses have proven a relationship between the local velocities and the type of plant communities.
Rights:
http://creativecommons.org/licenses/by-nc-sa/4.0/ and policy:public

2. Flow structure of coarse-grained slurry in a horizontal pipe

Creator:
Vlasák, Pavel, Kysela, Bohuš, and Chára, Zdenek
Format:
bez média and svazek
Type:
model:article and TEXT
Subject:
coarse-grained slurry, turbulent flow, pressure drop, velocity distribution, flow structure, concentration effect, hrubozrnné suspenze, turbulentní proudění, tlakové ztráty, rozdělení rychlostí, struktura proudu, and vliv koncentrace
Language:
Slovak
Description:
The flow behaviour of coarse-grained slurry depends on particle size, shape, density and concentration, and on the density and rheological properties of the carrier liquid. The present paper describes the results of an experimental investigation and flow visualisation of model coarse-grained particle-water mixtures in a closed pipe loop with smooth stainless steel pipes of inner diameter 36 mm. Glass balls and washed graded pebble gravel of mean diameter d50 = 6 mm were used as model coarse-grained material. The effect of slurry velocity and particle concentration on the slurry flow behaviour and pressure drop in the turbulent regime was evaluated. Particle distribution in the pipe cross-section and motion of particles along the pipe invert, particle saltation and particle conveying in the carrier liquid were investigated in a transparent pipe viewing section and motion of individual particles was described. Velocity profiles of the carrier liquid and conveyed particles were determined. and Tokové chování hrubozrnných suspenzí závisí na velikosti, tvaru a hustotě částic, koncentraci pevné fáze a hustotě a reologických vlastnostech nosné kapaliny. Článek popisuje výsledky experimentálního výzkumu a vizualizace proudění modelové hrubozrnné suspenze v experimentální potrubní lince s hladkým nerezovým potrubím s vnitřním průměrem 36 mm. Skleněné kuličky a praný oblý štěrk (kačírek) se středním zrnem d50 = 6 mm byly použity jako modelový materiál. Byl vyhodnocen vliv rychlosti proudění suspenze a koncentrace pevné fáze na chování a tlakové ztráty suspenze. Rozdělení částic v příčném průřezu potrubí a pohyb částic podél dna potrubí, jejich saltace a unášení v nosné kapalině byly zkoumány v transparentní části potrubí a byl popsán pohyb jednotlivých částic a pro vybrané případy byly stanoveny rychlostní profily nosné kapaliny a unášených částic.
Rights:
http://creativecommons.org/licenses/by-nc-sa/4.0/ and policy:public