scholarly journals Characteristics of flow rate, head loss and basket pressure drop relationship in a Rocla Versa Trap (VT) stormwater pollutant trap (SPT) in a 3-D laboratory scale model

2008 ◽  
Author(s):  
H. K. Saberi ◽  
H. Nikraz
Keyword(s):  
Pressure Drop ◽  
Flow Rate ◽  
Head Loss ◽  
Laboratory Scale ◽  
Scale Model

scholarly journals Predicting infusion pressure during pars plana vitrectomy: a physically based model

2019 ◽  
Vol 2 (3) ◽  
pp. 88-103
Author(s):  
Tommaso Rossi ◽  
Giorgio Querzoli ◽  
Giampiero Angelini ◽  
Alessandro Rossi ◽  
Carlo Malvasi ◽  
...  
Keyword(s):  
Pressure Drop ◽  
Flow Rate ◽  
Pars Plana Vitrectomy ◽  
Statistical Significance ◽  
Polynomial Equation ◽  
Head Loss ◽  
Infusion Pressure ◽  
Physically Based ◽  
Pars Plana ◽  
Best Fit

Purpose: Intraocular pressure (IOP) during pars plana vitrectomy (PPV) decreases as aspiration generates flow, a phenomenon known as head loss. Since direct measurement of the IOP during surgery is impractical, currently, available compensating systems infer IOP by measuring infusion flow rate and estimating corresponding pressure drop. The purpose of the present paper is to propose and validate a physically based algorithm of the infusion pressure drop as a function of flow. Methods: Complete infusion lines (20G, 23G, 25G and 27G) were set up and primed. The infusion bottle was set at incremental heights and flow rate measured 10 times and recorded as mean Å} SD. Overall head loss (OHL) was defined, according to hydraulics laws, as the sum of frictional head loss (FHL; i.e., pressure drop due to friction along tubing) and exit head loss (EHL). The latter is equal to the kinetic energy of the exiting flow through the trocar (FKE = V2/2g). A 2nd degree polynomial equation (i.e., ΔP = aQ2 + bQ, where ΔP is the pressure drop, or OHL, and Q is the volumetric flow) was derived for each gauge and compared to experimental data 2nd order polynomial best-fit curve. Results: Ninety-seven percent of the pressure values for all gauges predicted using the derived equation fell within 2 SD of the mean difference yielding a Bland-Altman statistical significance when compared to 91% of best fit curve. Conclusion: The derived equations accurately predicted the head loss for each given infusion line gauge and can help infer IOP during PPV.

Numerical and Experimental Study of Pressure Drop Reduction in a Power Plant Stack

2004 ◽  
Author(s):  
Murthy Lakshmiraju ◽  
Jie Cui ◽  
Stephen Idem ◽  
Sastry Munukutla
Keyword(s):  
Pressure Drop ◽  
Flow Rate ◽  
Power Plants ◽  
Experimental Studies ◽  
Maximum Flow ◽  
Scale Model ◽  
Navier Stokes ◽  
Navier Stokes Equation ◽  
Computational Fluid Dynamics Cfd ◽  
Flow Through

As governmental regulations on the emission of the power industry became more restrictive, many power plants operating today experience severe problems. The fans that handle the flow through the stack, that were originally designed to handle a certain maximum flow rate, are now required to handle even higher flow rates due to the introduction of emission control devices. In this study, computational fluid dynamics (CFD) and experimental studies have been carried out on the scale model of a stack to identify means for pressure drop reduction. The CFD model was constructed using the commercial software CFX-5.6. The model solves the Reynolds averaged Navier-Stokes equation with Shear-Stress turbulence model (SST) and the CFD results are validated by data taken from the scale model. Baffles of different orientation have been installed in the stack under different flow conditions. Both numerical and experimental results confirm that adding baffles can reduce the pressure drop in a stack significantly. Thus, with minimum effort, power plants can keep running the stacks at a higher flow rate.

Effect of Drip Line Hydrocyclone Design on Head Loss for Agricultural Irrigation

2017 ◽  
Author(s):  
Christian Ramirez ◽  
Deify Law
Keyword(s):  
Pressure Drop ◽  
Flow Rate ◽  
Water Flow Rate ◽  
Head Loss ◽  
Drip Line ◽  
Agricultural Irrigation ◽  
Ansys Fluent ◽  
Pressure Drops ◽  
Current Design ◽  
Volume Method

In the present work, computational fluid dynamics (CFD) analysis of an existing drip line hydrocyclone is performed in order to improve the current design for agricultural irrigation by understanding the effect of water flow rate on pressure drop and head loss. When water flows through a pipe, the pressure continuously drops in the stream-wise direction because of friction along the walls of the pipe. It is common to express this pressure drop in terms of an irreversible head loss. Numerical simulations are performed using the commercial CFD code ANSYS FLUENT with the finite volume method. The pressure drops of the hydrocyclone are computed numerically and they are in reasonable agreement with the experimental data provided by the Center for Irrigation Technology at Fresno State. For example, the measured pressure drop across the part is approximately 2.76 × 104 Pa at 1.89 × 10−4 m3/s inlet flow rate whereas the numerical pressure drop is roughly 2.62 × 104 Pa at 1.89 × 10−4 m3/s. Additionally, the present work shows head loss reduction by making changes to the existing hydrocyclone design including the length and diameter of the cavity as well as length of the outlet tube.

scholarly journals Development and Evaluation of Low Cost Drip Filter

2020 ◽  
pp. 87-94
Author(s):  
Balaji Kannan ◽  
N. Janani ◽  
S. Thangamani ◽  
A. Selvaperumal
Keyword(s):  
Pressure Drop ◽  
Flow Rate ◽  
Irrigation System ◽  
Low Cost ◽  
Water Productivity ◽  
Head Loss ◽  
Single Chamber ◽  
Uniformity Coefficient ◽  
Sand Particles ◽  
Micro Irrigation

Irrigation water is many a time contaminated with physical, chemical and biological impurities. Proper filtration is of paramount importance to prevent clogging in drip irrigation system thereby aiding in reduced maintenance of the micro irrigation system. This study was conducted on Development and Evaluation of Low cost filters in the Network project on “Engineering Interventions in Micro Irrigation Systems (MIS) for improving water productivity” under Consortia Research Platform on Farm Mechanization and Precision Farming during 2018 to 2020. The objectives of the study are to develop low cost filters and to test the developed system in the field for efficiency in terms of pressure drop throughout discharge and quality of output. It was observed that the discharge from the filter increases as the time increases. Pressure drop and head loss in the filter system increases with flow rate. Filtration efficiency is a percentage of sand particles divided by the TSS removed by the filter. Efficiency of the filter increased from 25% to 64% (double chamber filter) and 23% to 62% (single chamber filter) with flow range of 5 m3/h to 30 m3/h. As flow rate increases, soil particles retained and efficiency of the filter increased with increase in head loss. Filter materials and screen filter removed the sand particles effectively. Uniformity coefficient of 0.95 was observed in single chamber filter which is suitable for small farm application.

Analysis of the effects of pressure profile, furnish, and microfibrillated cellulose on the dewatering of papermaking furnishes

TAPPI Journal ◽  
2015 ◽  
Vol 14 (5) ◽  
pp. 325-337 ◽  
Author(s):  
ANTTI KOPONEN ◽  
SANNA HAAVISTO ◽  
JOHANNA LIUKKONEN ◽  
JUHA SALMELA
Keyword(s):  
Pressure Drop ◽  
Flow Rate ◽  
Flow Resistance ◽  
Pressure Profile ◽  
Pilot Scale ◽  
Microfibrillated Cellulose ◽  
Laboratory Scale ◽  
Filtration Process ◽  
Furnish Type ◽  
Solids Content

In this paper, we present an improved experimental method for studying the initial dewatering process in papermaking. We studied the effects of the dewatering pressure profile, the furnish type, and microfibrillated cellulose (MFC) on the development of flow resistance and the final solids content of the filtered sheet. The major difference from the previous studies is the possibility to control the dewatering pressure profile during filtration. The filtration process is monitored by measuring the pressure drop over the filtrated sheet and the flow rate through the filtered sheet as a function of time. In the end, the final solids content is measured. Our results indicate that the sheet solids content after the initial dewatering depends on the magnitude and the shape of the pressure profile used during the filtration and that this dependency remains after wet pressing. Laboratory scale measurements are repeated in pilot scale using a papermaking research environment, with comparable results. Surprisingly, we found that the addition of MFC increases the solids content. This was verified in laboratory and pilot scale studies. Overall, this study shows that laboratory scale measurements can be useful in determining the optimal dewatering conditions for different furnish types.

Study of fluid flow through a channel deformed by piezoelement

2018 ◽  
Vol 13 (3) ◽  
pp. 1-10 ◽  
Author(s):  
I.Sh. Nasibullayev ◽  
E.Sh Nasibullaeva ◽  
O.V. Darintsev
Keyword(s):  
Fluid Flow ◽  
Pressure Drop ◽  
Boundary Conditions ◽  
Flow Rate ◽  
Contact Surface ◽  
Piezoelectric Element ◽  
Neumann Boundary ◽  
Differential Pressure ◽  
Physical Parameters ◽  
Flow Through

The flow of a liquid through a tube deformed by a piezoelectric cell under a harmonic law is studied in this paper. Linear deformations are compared for the Dirichlet and Neumann boundary conditions on the contact surface of the tube and piezoelectric element. The flow of fluid through a deformed channel for two flow regimes is investigated: in a tube with one closed end due to deformation of the tube; for a tube with two open ends due to deformation of the tube and the differential pressure applied to the channel. The flow rate of the liquid is calculated as a function of the frequency of the deformations, the pressure drop and the physical parameters of the liquid.

Pressure Drop Measurements for Air Flow Through Open-Cell Aluminum Foam

2004 ◽  
Author(s):  
Nihad Dukhan ◽  
Angel Alvarez
Keyword(s):  
Reynolds Number ◽  
Pressure Drop ◽  
Flow Rate ◽  
Aluminum Foam ◽  
Flow Direction ◽  
The Other ◽  
Turbulent Regime ◽  
Thick Sample ◽  
Open Cell ◽  
Two Samples

Wind-tunnel pressure drop measurements for airflow through two samples of forty-pore-per-inch commercially available open-cell aluminum foam were undertaken. Each sample’s cross-sectional area perpendicular to the flow direction measured 10.16 cm by 24.13 cm. The thickness in the flow direction was 10.16 cm for one sample and 5.08 cm for the other. The flow rate ranged from 0.016 to 0.101 m3/s for the thick sample and from 0.025 to 0.134 m3/s for the other. The data were all in the fully turbulent regime. The pressure drop for both samples increased with increasing flow rate and followed a quadratic behavior. The permeability and the inertia coefficient showed some scatter with average values of 4.6 × 10−8 m2 and 2.9 × 10−8 m2, and 0.086 and 0.066 for the thick and the thin samples, respectively. The friction factor decayed with the Reynolds number and was weakly dependent on the Reynolds number for Reynolds number greater than 35.

Simultaneous Measuring Method for Both Volumetric Flow Rates of Air-Water Mixture Using a Turbine Flowmeter

1996 ◽  
Vol 118 (1) ◽  
pp. 29-35 ◽  
Author(s):  
K. Minemura ◽  
K. Egashira ◽  
K. Ihara ◽  
H. Furuta ◽  
K. Yamamoto
Keyword(s):  
Pressure Drop ◽  
Flow Rate ◽  
Volumetric Flow Rate ◽  
Oil Field ◽  
Liquid Density ◽  
Water Mixture ◽  
Rotor Speed ◽  
Flow Rates ◽  
Field Development ◽  
Turbine Flowmeter

A turbine flowmeter is employed in this study in connection with offshore oil field development, in order to measure simultaneously both the volumetric flow rates of air-water two-phase mixture. Though a conventional turbine flowmeter is generally used to measure the single-phase volumetric flow rate by obtaining the rotational rotor speed, the method proposed additionally reads the pressure drop across the meter. After the pressure drop and rotor speed measured are correlated as functions of the volumetric flow ratio of the air to the whole fluid and the total volumetric flow rate, both the flow rates are iteratively evaluated with the functions on the premise that the liquid density is known. The evaluated flow rates are confirmed to have adequate accuracy, and thus the applicability of the method to oil fields.

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