The Effect of Longitudinal Slope on Solids Transport and Friction in Flow above Eroded Bed

Milica Jovanovic

Diplomová práce

Abstract:

This thesis presents results of the work analyzing the effect of the longitudinal slope of the top of a stationary deposit on solids transport and solids-based friction in flow carrying solid particles above the bed deposit in a pressurized pipe. The analysis is based on results of the experiments carried out in a 100-mm pipe loop with an inclinable U-pipe section in the laboratory of Institute of Hydrodynamics of Czech Academy of Science in Prague. Integral flow parameters and concentration profiles were measured in flows above deposit in the pipe installed to a broad range of inclination angles between -35 and +35 degree from horizontal. In the literature, various versions of formulas can be found for solids (bed load) transport. However, all of them take the effect of the longitudinal slope insufficiently into account as they inherently expect an application to conditions where a variation in the flow slope is marginal. In this work, I employ the classical Meyer-Peter and Müller (MPM) transport formula for bed load and the bed friction formula derived recently for the intense transport condition. The aim is to use the measurement results for the observed flows including those at very steep inclinations to examine how the effect of the longitudinal slope should be implemented in the formulae to correctly predict the transport and friction of bed load. In addition, sensitivity analyses are done in order to show a detailed representation of the influence of changing input parameters on the output results.Applications of the presented research results include sediment transport and morphology of mountain streams as well as settling slurry flows in inclined pressurized pipes where the transport and friction formulae are used in a layered model predicting the energy head loss and internal structure of the stratified slurry flow.

Keywords

solids transport, sheet flow, bed load, pipe experiment

Jazyk práce: angličtina

Datum vytvoření / odevzdání či podání práce: 20. 5. 2020

Obhajoba závěrečné práce

• Vedoucí: prof. Dr. Ing. Václav Matoušek

Česká zemědělská univerzita v Praze

Fakulta životního prostředí

Magisterský studijní program / obor:
Krajinné inženýrství / Environmental Modelling