ON THE CONCEPT OF MEAN HYDRAULIC RADIUS
BY USING THE HYDRODYNAMIC ANALOGY BETWEEN THE TORSION OF A UNIFORM BAR WITH ARBITRARY CROSS-SECTION AND VISCOUS FLOW THROUGH A CHANNEL OF THE SAME SHAPE, THE FLOW RATE THROUGH ANY CHANNEL MAY BE PREDICTED BY (1) COMPUTATION OF THE ASPECT RATIO OF THE CROSS-SECTION OF THE CHANNEL, (2) MEASUREMENT OF THE AREA USING A PLANIMETER, (3) MEASUREMENT OF THE WETTED PERIMETER OF FLOW, AND (4) OBSERVATION OF THE NUMBER OF SIGNIFICANT SIDES COMPRISING THE CROSS-SECTION. THE MEAN HYDRAULIC RADIUS MAY BE OBTAINED AS THE QUOTIENT OF (2) AND (3). THIS PARAMETER IS THEN MODIFIED BY (1) AND (4) TO IMPROVE THE ACCURACY OF THE PREDICTION. FOR CHANNELS WITH VARIABLE SHAPE AND SIZE ALONG THEIR LENGTH, THE SAME CONCEPTS MAY BE USED. IN SUCH CASES, AN EQUIVALENT AREA IS DEFINED IN THE COMPUTATION OF HYDRAULIC RADIUS ACCORDING TO A METHOD OUTLINED IN THE APPENDIX. EXPERIMENTAL SUPPORT FOR THE CONCEPTS PROPOSED HAS BEEN FURNISHED FROM EXTENSIVE TESTS, USING PLATES WITH REGULAR AND RANDOM ASPERITIES. THE VALIDITY OF THE MEAN HYDRAULIC RADIUS CONCEPT HAS LED TO THE DEVELOPMENT OF A SCIENTIFIC OUTFLOW INSTRUMENT WHICH IS CAPABLE OF PREDICTING THE DRAINAGE ABILITY OF ROAD SURFACES SUBJECTED TO PNEUMATIC TIRE TRAFFIC. /AUTHOR/
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Supplemental Notes:
- Vol 95, No HY4, PROC PAPER 6691, PP 1305-1319
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Authors:
- MOORE, D F
- Publication Date: 1969-7
Media Info
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Serial:
- Journal of the Hydraulics Division
- Publisher: American Society of Civil Engineers
Subject/Index Terms
- TRT Terms: Flow; Forecasting; Hydraulic properties; Instrumentation; Mean (Statistics); Pneumatic equipment; Rates; Streamflow; Surface drainage; Tires; Water
- Old TRIS Terms: Highway drainage; Hydraulic radius; Mean (Statistical); Pneumatic tire
- Subject Areas: Highways; Hydraulics and Hydrology; Vehicles and Equipment;
Filing Info
- Accession Number: 00204242
- Record Type: Publication
- Files: TRIS
- Created Date: Sep 29 1994 12:00AM