Location
Rolla, Missouri
Session Dates
11 Jun 1999 - 17 Jun 1999
Keywords and Phrases
Equivalent Roughness; Friction Drag; ERM; Flow Direction of Diagonal Airway
Abstract
Some roadways, which do not behave as "wholly rough pipe" as we expected, will have different impact on airflow in a mine ventilation network because of the low Reynolds numbers. For a "non-Wholly-rough" roadway, its resistance factor (R) or the friction factor (¦) is not only dependent upon the relative roughness but also dependent upon the Reynolds number, which varies directly as the flow rate. In this case, R or ¦ is no longer a constant independent of flow rate. Thus, in order to correctly calculate the friction drag of the same roadway for different flow rates, ¦ must be correctly calculated firstly by an appropriate method. After introducing the concept of Equivalent Roughness of mine roadway, the Colebrook formula can serve as this method. Known from the conventional method for calculating the friction drag of mine roadway, the method introduced in this paper is called the Equivalent Roughness Method (ERM). By using the ERM to analyze the airflow direction of the diagonal airway in a simple diagonal network, a new calculating example is presented.
Department(s)
Mining Engineering
Meeting Name
8th U.S. Mine Ventilation Symposium
Publisher
University of Missouri--Rolla
Document Version
Final Version
Document Type
Article - Conference proceedings
File Type
text
Language
English
Recommended Citation
Zhou, Yan and Wang, Xingshen, "Equivalent Roughness and Its Application in Calculating Friction Drag of Mine Roadway" (1999). U.S. Mine Ventilation Symposium. 2.
https://scholarsmine.mst.edu/usmvs/8usmvs/8usmvs-theme18/2
Equivalent Roughness and Its Application in Calculating Friction Drag of Mine Roadway
Rolla, Missouri
Some roadways, which do not behave as "wholly rough pipe" as we expected, will have different impact on airflow in a mine ventilation network because of the low Reynolds numbers. For a "non-Wholly-rough" roadway, its resistance factor (R) or the friction factor (¦) is not only dependent upon the relative roughness but also dependent upon the Reynolds number, which varies directly as the flow rate. In this case, R or ¦ is no longer a constant independent of flow rate. Thus, in order to correctly calculate the friction drag of the same roadway for different flow rates, ¦ must be correctly calculated firstly by an appropriate method. After introducing the concept of Equivalent Roughness of mine roadway, the Colebrook formula can serve as this method. Known from the conventional method for calculating the friction drag of mine roadway, the method introduced in this paper is called the Equivalent Roughness Method (ERM). By using the ERM to analyze the airflow direction of the diagonal airway in a simple diagonal network, a new calculating example is presented.
