THERMAL SCIENCE

International Scientific Journal

ADAPTING THE FORCHHEIMER EQUATION FOR THE FLOW OF AIR THROUGH WHEAT STRAW BEDS

ABSTRACT
The paper presents the results of an experimental investigation of air pressure drop while flowing through wheat straw beds. According to Darcy’s law, the smaller the porosity of the bed is, the bigger the pressure drop will be. The investigation was conducted using three different porosities (or three bed densities), and for two different air flow rates. After determining porosity (which is directly measurable), the permeability of straw could be found. For high flow velocities, such as the velocity of air flowing through a straw bale, the Forchheimer equation becomes more relevant as a correction of Darcy’s law with inertial effects included. Otherwise, the permeability tensor depends only on the geometry of the porous medium. With permeability known, the Forchheimer equation coefficients can be easily estimated. These results may be important for the future development of efficient biomass combustion facilities. The measurement methods and facility characteristics are described in more detail.
KEYWORDS
PAPER SUBMITTED: 2015-10-05
PAPER REVISED: 1970-01-01
PAPER ACCEPTED: 2016-02-04
PUBLISHED ONLINE: 2016-02-20
DOI REFERENCE: https://doi.org/10.2298/TSCI151005030D
CITATION EXPORT: view in browser or download as text file
THERMAL SCIENCE YEAR 2016, VOLUME 20, ISSUE Supplement 2, PAGES [S463 - S470]
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© 2019 Society of Thermal Engineers of Serbia. Published by the Vinča Institute of Nuclear Sciences, Belgrade, Serbia. This article is an open access article distributed under the terms and conditions of the Creative Commons Attribution-NonCommercial-NoDerivs 4.0 International licence