scholarly journals Investigating the Head Loss (Pressure Drop) and Flow Rate with Different Inlet Injectary Angle in Junction and Analysis by using Mathematical Modelling and Software

2020 ◽  
Vol 8 (6) ◽  
pp. 1364-1375
Author(s):  
Prof. Pankaj S. Shirsath
Keyword(s):  
Pressure Drop ◽  
Mathematical Modelling ◽  
Flow Rate ◽  
Head Loss

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.

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.

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.

Experimental Investigation of Effect of Tip Coolant Ejection on Internal Flow Characteristics Within a Realistic Blade Coolant Channel

2013 ◽  
Author(s):  
Jian Pu ◽  
Zhaoqing Ke ◽  
Jianhua Wang ◽  
Lei Wang ◽  
Hongde You
Keyword(s):  
Experimental Investigation ◽  
Reynolds Number ◽  
Pressure Drop ◽  
Turbine Blade ◽  
Flow Rate ◽  
Flow Characteristics ◽  
Reynolds Numbers ◽  
Flow Ratio ◽  
Lp Turbine ◽  
Mass Flow Ratio

This paper presents an experimental investigation on the characteristics of the fluid flow within an entire coolant channel of a low pressure (LP) turbine blade. The serpentine channel, which keeps realistic blade geometry, consists of three passes connected by a 180° sharp bend and a semi-round bend, 2 tip exits and 25 trailing edge exits. The mean velocity fields within several typical cross sections were captured using a particle image velocimetry (PIV) system. Pressure and flow rate at each exit were determined through the measurements of local static pressure and volume flow rate. To optimize the design of LP turbine blade coolant channels, the effect of tip ejection ratio (ER) from 180° sharp bend on the flow characteristics in the coolant channel were experimentally investigated at a series of inlet Reynolds numbers from 25,000 to 50,000. A complex flow pattern, which is different from the previous investigations conducted by a simplified square or rectangular two-pass U-channel, is exhibited from the PIV results. This experimental investigation indicated that: a) in the main flow direction, the regions of separation bubble and flow impingement increase in size with a decrease of the ER; b) the shape, intensity and position of the secondary vortices are changed by the ER; c) the mass flow ratio of each exit to inlet is not sensitive to the inlet Reynolds number; d) the increase of the ER reduces the mass flow ratio through each trailing edge exit to the extent of about 23–28% of the ER = 0 reference under the condition that the tip exit located at 180° bend is full open; e) the pressure drop through the entire coolant channel decreases with an increase in the ER and inlet Reynolds number, and a reduction about 35–40% of the non-dimensional pressure drop is observed at different inlet Reynolds numbers, under the condition that the tip exit located at 180° bend is full open.

Mathematical modelling of the selective intake process from the interior volume in a three-layer stratified reservoir

2020 ◽  
Author(s):  
И.Д. Музаев ◽  
К.С. Харебов ◽  
Н.И. Музаев
Keyword(s):  
Boundary Value Problem ◽  
Mathematical Modelling ◽  
Water Intake ◽  
Flow Rate ◽  
Intermediate Layer ◽  
Intake Process ◽  
Intake Pipe ◽  
Stratified Reservoir ◽  
Selective Intake ◽  
Interior Volume

Проведено механико-математическое моделирование селективного водозаборного процесса в трехслойном стратифицированном водоеме, когда вода забирается из внутреннего объема промежуточного слоя водоема. Составленная математическая модель представляет контактную начально-краевую задачу теории поверхностных и внутренних гравитационных волн в идеальной несжимаемой жидкости. Водозабор из внутреннего пространства промежуточного слоя смоделирован в виде объемного стока с бесконечно малой толщиной и конечным сточным расходом. В результате решения поставленной начально-краевой задачи получена система расчетных формул, которая с привлечением компьютерных средств позволяет выбирать диаметр водозаборной трубы и расход через нее, вычислять отметку глу- бинного расположения конца водозаборной трубы. Выбор этих параметров обеспе- чивает селективный водозабор исключительно из промежуточного слоя, где вода чище и холоднее, чем в других слоях водоема. The purpose of this work is to carry out mathematical modelling of selective water intake process in a three-layer stratified reservoir, when the water is taken from the interior volume of the intermediate layer of the reservoir. In the methodology for solving the problem, the water intake from the interior volume of the intermediate layer is modelled as a finite flow rate drain of fluid trough an infinitely thin layer. The contact initial-boundary value problem of the theory of surface and internal gravitational waves in an ideal incompressible fluid is used as a mathematical model of the water intake process. As a result we obtain a system of calculation formulas for estimation of the diameter of water intake pipe and the flow rate through it. The depth mark of the end of the water intake pipe was calculated. Originality/value: 1. The boundary value problem simulating a selective water intake process from the internal volume of the intermediate layer of a three-layer stratified reservoir was formulated and solved. 2. On the basis of the obtained set of formulas, computer experiments were performed and thus the regularities of the influence of the above external input parameters on the process were established. 3. The choice of these parameters provides selective intake exclusively from the intermediate layer, where the water is cleaner than in the lower layer and colder in summer than in the upper layer.

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