Evaluation of multi-holed orifice flowmeters under developing flow conditions – An experimental study

2021 ◽  
Vol 79 ◽  
pp. 101894
Author(s):  
Aneeq Raheem ◽  
Abdus Saboor Baseer Siddiqi ◽  
Asim Ibrahim ◽  
Atta Ullah ◽  
Mansoor Hameed Inayat
Keyword(s):  
Experimental Study ◽  
Flow Conditions ◽  
Developing Flow

An Experimental Study on the Transport of Sediment in Sewer Pipes with a Permanent Deposit

1992 ◽  
Vol 25 (8) ◽  
pp. 115-122 ◽  
Author(s):  
G. S. Perrusquía
Keyword(s):  
Experimental Study ◽  
Critical Shear Stress ◽  
Side Wall ◽  
Bedload Transport ◽  
Flow Conditions ◽  
Sewer Pipes ◽  
Sediment Bed ◽  
Concrete Pipe ◽  
Geometric Factors ◽  
Particle Parameters

An experimental study of the transport of sediment in a part-full pipe was carried out in a concrete pipe. The experiments were confined to bedload transport. The purpose of this study was to analyze the flow conditions that characterize the stream traction in pipe channels and their relationship to flow resistance and sediment transport rate. Three procedures used in this kind of experimental study were tested and found valid: 1) the vertical velocity distribution near the sediment bed can be described by the velocity-defect law, 2) the side wall elimination procedure can be used to compute the hydraulic radius of the sediment bed, and 3) the critical shear stress of the sediment particles can be obtained by using Shields' diagram. A relationship to estimate bedload transport, based on dimensional analysis, was proposed. This was expressed in terms of both flow and particle parameters as well as geometric factors. Further experimental work is recommended before this relationship can be fully incorporated in a simulation model for the analysis of storm sewers.

Experimental Study of Near-Field Entrainment of Moderately Overpressured Jets

2011 ◽  
Vol 133 (5) ◽  
Author(s):  
Stephen A. Solovitz ◽  
Larry G. Mastin ◽  
Farhad Saffaraval
Keyword(s):  
High Speed ◽  
Near Field ◽  
Flow Region ◽  
Flow Conditions ◽  
Entrainment Ratio ◽  
One Dimensional ◽  
Column Collapse ◽  
Developing Flow ◽  
Image Velocimetry ◽  
Velocity Flow

Particle image velocimetry (PIV) experiments have been conducted to study the velocity flow fields in the developing flow region of high-speed jets. These velocity distributions were examined to determine the entrained mass flow over a range of geometric and flow conditions, including overpressured cases up to an overpressure ratio of 2.83. In the region near the jet exit, all measured flows exhibited the same entrainment up until the location of the first shock when overpressured. Beyond this location, the entrainment was reduced with increasing overpressure ratio, falling to approximately 60% of the magnitudes seen when subsonic. Since entrainment ratios based on lower speed, subsonic results are typically used in one-dimensional volcanological models of plume development, the current analytical methods will underestimate the likelihood of column collapse. In addition, the concept of the entrainment ratio normalization is examined in detail, as several key assumptions in this methodology do not apply when overpressured.

Measurements of Secondary Flows in a Rotating Duct

1972 ◽  
Vol 94 (4) ◽  
pp. 261-270 ◽  
Author(s):  
R. E. Wagner ◽  
H. R. Velkoff
Keyword(s):  
Experimental Study ◽  
Pressure Distribution ◽  
Cross Section ◽  
Experimental Work ◽  
Cross Flow ◽  
Secondary Flows ◽  
Working Fluid ◽  
Longitudinal Vortices ◽  
Developing Flow ◽  
Analytical Work

The paper presents a review of analytical and experimental work which has been done on flows in rotating ducts. It presents the results of an experimental study to measure the secondary flows predicted by the previous analytical work. A duct of approximately 3 ft in length with a cross section of 2 × 5 in. was rotated up to speeds of 300 rpm. Air was used as the working fluid. Static pressures, total pressures, and yaw angles were measured at selected points along the channel. The flow regime examined was the developing flow from the entrance to the exit of the channel. Examination of the data revealed the presence of two longitudinal vortices which extended the length of the channel. Pressure distribution across the height of the channel and across the width of the channel was obtained. The magnitude of the cross-flow velocities in the channel were determined and mapped. It was found that the data for various rotational speeds could be collapsed upon a single curve by dividing all data by the rotational speeds. The results of the experimental study provide solid verification for the hypothesis of longitudinal vortices in rotating ducts.

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