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Non-Newtonian pressure loss and discharge coefficients for short square-edged orifices plates
Author(s)
Ntamba Ntamba, Butteur Mulumba
Date Issued
2011
Type
Thesis
Publisher
Cape Peninsula University of Technology
Abstract
Despite the extensive research work carried out on flow through short square-edged orifice
plates over the last century (e.g. Johansen, 1930; Benedict, 1977; Alvi et al., 1978; Swamee,
2005; ESDU, 2007), gaps in the engineering data still exist for certain ranges of flow conditions
and geometries. The majority of data available in the literature are for Newtonian fluids in the
turbulent flow regime (ESDU, 2007). Insufficient data have been observed for the orifice with
pipe diameter ratio, β = 0.2, in the laminar flow regime. There are no experimental data for β = 0.3 and 0.57. The objective of this thesis was to conduct wide-ranging experimental studies
of the flow in orifice plates, which included those geometrical configurations, by measuring
pressure loss coefficients and discharge coefficients across the orifice plates using both
Newtonian fluids and non-Newtonian fluids in both laminar and turbulent flow regimes.
The test work was conducted on the valve test rig at the Cape Peninsula University of
Technology. Four classical circular short square-edged orifice plates having, β = 0.2, 0.3, 0.57
and 0.7, were tested. In addition, two generation 0 Von Koch orifice plates (Von Koch, 1904),
with equivalent cross sectional area were also tested for β = 0.57. Water was used as
Newtonian fluid to obtain turbulent regime data and also for calibration purposes to ensure
measurement accuracy and carboxymethyl cellulose, bentonite and kaolin slurries were used at
different concentrations to obtain laminar and transitional loss coefficient data. The hydraulic
grade line method was used to evaluate pressure loss coefficients (Edwards et al., 1985), while
the flange tap arrangement method was used to determine the discharge coefficients (ESDU,
2007). A tube viscometer with three different pipe diameters was used to obtain the rheological
properties of the fluids.
The results for each test are presented in the form of pressure loss coefficient (kor) and
discharge coefficient (Cd) against pipe Reynolds number (Re)
plates over the last century (e.g. Johansen, 1930; Benedict, 1977; Alvi et al., 1978; Swamee,
2005; ESDU, 2007), gaps in the engineering data still exist for certain ranges of flow conditions
and geometries. The majority of data available in the literature are for Newtonian fluids in the
turbulent flow regime (ESDU, 2007). Insufficient data have been observed for the orifice with
pipe diameter ratio, β = 0.2, in the laminar flow regime. There are no experimental data for β = 0.3 and 0.57. The objective of this thesis was to conduct wide-ranging experimental studies
of the flow in orifice plates, which included those geometrical configurations, by measuring
pressure loss coefficients and discharge coefficients across the orifice plates using both
Newtonian fluids and non-Newtonian fluids in both laminar and turbulent flow regimes.
The test work was conducted on the valve test rig at the Cape Peninsula University of
Technology. Four classical circular short square-edged orifice plates having, β = 0.2, 0.3, 0.57
and 0.7, were tested. In addition, two generation 0 Von Koch orifice plates (Von Koch, 1904),
with equivalent cross sectional area were also tested for β = 0.57. Water was used as
Newtonian fluid to obtain turbulent regime data and also for calibration purposes to ensure
measurement accuracy and carboxymethyl cellulose, bentonite and kaolin slurries were used at
different concentrations to obtain laminar and transitional loss coefficient data. The hydraulic
grade line method was used to evaluate pressure loss coefficients (Edwards et al., 1985), while
the flange tap arrangement method was used to determine the discharge coefficients (ESDU,
2007). A tube viscometer with three different pipe diameters was used to obtain the rheological
properties of the fluids.
The results for each test are presented in the form of pressure loss coefficient (kor) and
discharge coefficient (Cd) against pipe Reynolds number (Re)
Additional information
Thesis (MTech (Mechanical Engineering))--Cape Peninsula University of Technology, 2011.
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Name
NON-NEWTONIAN PRESSURE LOSS AND DISCHARGE COEFFICIENTS FOR SHORT SQUARE-EDGED ORIFICE PLATES.pdf
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5.95 MB
Format
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