Some Dimensionless Numbers Used in Fluid Mechanics

In order to provide specific references and suggestions for the design and operation of underground pumping stations, in this paper, an experimental model of an underground pumping station, including 4 pumps and 2 pump intakes (primary and secondary), was obtained through similitude of fluid mechanics. The phase diagrams of various vortices, in terms of different dimensionless numbers are presented, which can reveal their appearance and evolution process. Three specific cases with different vortex flows were analyzed. The experiment results may provide a reference for the current design guidelines for underground pumping stations.

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The Theoretical Analysis of Mass and Energy Flow Through Solar Collector – Chimney System

Civil and Environmental Engineering Reports ◽

10.1515/ceer-2017-0008 ◽

2017 ◽

Vol 24 (1) ◽

pp. 117-131 ◽

Cited By ~ 1

Author(s):

Zygmunt Lipnicki ◽

Marta Gortych ◽

Anna Staszczuk ◽

Tadeusz Kuczyński

Keyword(s):

Reynolds Number ◽

Theoretical Analysis ◽

Fluid Mechanics ◽

Energy Flow ◽

Solar Collector ◽

System Of Equations ◽

Dimensionless Numbers ◽

Collector System ◽

Flow Through ◽

Geometrical Dimensions

Abstract The goal of the paper was to simplify the designing process for mass and energy flow through solar collector - chimney system. Theoretical analysis allowed to get involved system of three nonlinear analytical equations in dimensionless forms that have been saved. Dimensionless numbers for the problem are well known in the literature on fluid mechanics and thermodynamics: Reynolds, Grashof, Galileo, Biot and Prandtl. In the analyzed equations are also dimensionless geometric parameters expressing the ratios of basic geometrical dimensions of the collector system-chimney: the radius disc collector to the thickness gap, the height and radius of the chimney. In the system of equations, the Reynolds number is treated as the determined number, which is a novelty of the method used.

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