scholarly journals Four Layer Cylindrical Model of Mucus Transport in the Lung: Effect of Prolonged Cough

2019 ◽  
Vol 19 (1) ◽  
pp. 53-63
Author(s):  
Arti Saxena ◽  
Vijay Kumar ◽  
JB Shukla
Keyword(s):  
Fluid Flow ◽  
Flow Rate ◽  
Circular Tube ◽  
Medical Science ◽  
Moist Air ◽  
Serous Fluid ◽  
Mixture Flow ◽  
Flow Rates ◽  
Immotile Cilia ◽  
Laminar Condition

Background: In this paper, a four layer model of the simultaneous and coaxial flow of moist air, mucus, mixture of mucin and periciliary liquid and serous fluid (assumed to be incompressible and Newtonian fluids) in a circular tube under time dependent pressure gradient representing prolonged cough is analyzed to study the mucus transport in an airway in the presence of prolonged cough. It is assumed that air and mucus flow under quasi steady state turbulent conditions while the mixture of mucin and periciliary liquid and serous layer surrounding mixture layer flows under unsteady laminar condition in presence of immotile cilia carpet. Result: It is shown that the mucus transport increases as the viscosity of serous fluid decreases. Also the mixture and serous fluid flow rates increase as the viscosity of serous fluid decreases. It is also observed that the effect of resistance to flow by serous fluid in the cilia bed is to decrease flow rates. The flow rates of mucus and mixture of mucin and periciliary fluid increase as the viscosity of mixture decreases also air and mixture of mucus and periciliary fluid flow rates increase as the thickness of mixture increases. Conclusion: As the thickness of mucus increases its flow rate increases on the other hand the mixture flow rate, mucus and serous fluid flow rate decreases with the increase of the mixture thickness. Bangladesh Journal of Medical Science Vol.19(1) 2020 p.53-63

Study on the effect of pore-scale heterogeneity and flow rate during repetitive two-phase fluid flow in microfluidic porous media

2021 ◽  
pp. petgeo2020-062
Author(s):  
Jingtao Zhang ◽  
Haipeng Zhang ◽  
Donghee Lee ◽  
Sangjin Ryu ◽  
Seunghee Kim
Keyword(s):  
Porous Media ◽  
Fluid Flow ◽  
Flow Rate ◽  
Sweep Efficiency ◽  
Residual Saturation ◽  
Flow Rates ◽  
Content Type ◽  
Lower Flow ◽  
Supplementary Material ◽  
Lower Flow Rate

Various energy recovery, storage, conversion, and environmental operations may involve repetitive fluid injection and, thus, cyclic drainage-imbibition processes. We conducted an experimental study for which polydimethylsiloxane (PDMS)-based micromodels were fabricated with three different levels of pore-space heterogeneity (coefficient of variation, where COV = 0, 0.25, and 0.5) to represent consolidated and/or partially consolidated sandstones. A total of ten injection-withdrawal cycles were applied to each micromodel at two different flow rates (0.01 and 0.1 mL/min). The experimental results were analyzed in terms of flow morphology, sweep efficiency, residual saturation, the connection of fluids, and the pressure gradient. The pattern of the invasion and displacement of nonwetting fluid converged more readily in the homogeneous model (COV = 0) as the repetitive drainage-imbibition process continued. The overall sweep efficiency converged between 0.4 and 0.6 at all tested flow rates, regardless of different flow rates and COV in this study. In contrast, the effective sweep efficiency was observed to increase with higher COV at the lower flow rate, while that trend became the opposite at the higher flow rate. Similarly, the residual saturation of the nonwetting fluid was largest at COV = 0 for the lower flow rate, but it was the opposite for the higher flow rate case. However, the Minkowski functionals for the boundary length and connectedness of the nonwetting fluid remained quite constant during repetitive fluid flow. Implications of the study results for porous media-compressed air energy storage (PM-CAES) are discussed as a complementary analysis at the end of this manuscript.Supplementary material: Figures S1 and S2 https://doi.org/10.6084/m9.figshare.c.5276814.Thematic collection: This article is part of the Energy Geoscience Series collection available at: https://www.lyellcollection.org/cc/energy-geoscience-series

scholarly journals Learning The Fluid/Flow Properties Using Microfluidics

2019 ◽  
Vol 215 ◽  
pp. 10002
Author(s):  
Pooria Hadikhani ◽  
Navid Borhani ◽  
S. Mohammad H. Hashemi ◽  
Demetri Psaltis
Keyword(s):  
Neural Networks ◽  
Fluid Flow ◽  
Microfluidic Device ◽  
Flow Rate ◽  
Deep Neural Networks ◽  
Good Accuracy ◽  
Flow Properties ◽  
Flow Rates

Deep neural networks (DNN) are employed to measure the flow rate and the concentration of the liquid using the images of the droplets in a microfluidic device. The trained networks are able to measure flow rates and concentrations with good accuracy.

scholarly journals Effect of Fluid Flow Rate on Efficacy of Fluid Warmer: An In Vitro Experimental Study

2018 ◽  
Vol 2018 ◽  
pp. 1-4
Author(s):  
Vorasruang Thongsukh ◽  
Chanida Kositratana ◽  
Aree Jandonpai
Keyword(s):  
Fluid Flow ◽  
Flow Rate ◽  
Room Temperature ◽  
Core Body Temperature ◽  
Infusion Pump ◽  
Outlet Temperature ◽  
Fluid Temperature ◽  
Fluid Flow Rate ◽  
Flow Rates ◽  
Fluid Warmer

Introduction. In patients who require a massive intraoperative transfusion, cold fluid or blood transfusion can cause hypothermia and potential adverse effects. One method by which to prevent hypothermia in these patients is to warm the intravenous fluid before infusion. The aim of this study was to determine the effect of the fluid flow rate on the efficacy of a fluid warmer. Methods. The room air temperature was controlled at 24°C. Normal saline at room temperature was used for the experiment. The fluid was connected to an infusion pump and covered with a heater line, which constantly maintained the temperature at 42°C. The fluid temperature after warming was measured by an insulated thermistor at different fluid flow rates (100, 300, 600, 900, and 1200 mL/h) and compared with the fluid temperature before warming. Effective warming was defined as an outlet fluid temperature of >32°C. Results. The room temperature was 23.6°C ± 0.9°C. The fluid temperature before warming was 24.95°C ± 0.5°C. The outlet temperature was significantly higher after warming at all flow rates (p<0.001). The increases in temperature were 10.9°C ± 0.1°C, 11.5°C ± 0.1°C, 10.2°C ± 0.1°C, 10.1°C ± 0.7°C, and 8.4°C ± 0.2°C at flow rates of 100, 300, 600, 900, and 1200 mL/h, respectively. The changes in temperature among all different flow rates were statistically significant (p<0.001). The outlet temperature was >32°C at all flow rates. Conclusions. The efficacy of fluid warming was inversely associated with the increase in flow rate. The outlet temperature was <42°C at fluid flow rates of 100 to 1200 mL/h. However, all outlet temperatures reached >32°C, indicating effective maintenance of the core body temperature by infusion of warm fluid.

scholarly journals Electrochemical Approach to Measure Physiological Fluid Flow Rates

2021 ◽  
Vol 9 ◽  
Author(s):  
Srivats Sarathy ◽  
Marco A. Nino ◽  
Abduldattar H. Alsaedi ◽  
Srinivasan Rajagopal ◽  
Syed Mubeen ◽  
...  
Keyword(s):  
Fluid Flow ◽  
Flow Rate ◽  
Current Amplitude ◽  
Rate Measurement ◽  
Flow Rate Measurement ◽  
Flow Rates ◽  
Ac Voltammetry ◽  
Electrochemical Approach ◽  
Physiological Fluid

In vivo measurement of the flow rate of physiological fluids such as the blood flow rate in the heart is vital in critically ill patients and for those undergoing surgical procedures. The reliability of these measurements is therefore quite crucial. However, current methods in practice for measuring flow rates of physiological fluids suffer from poor repeatability and reliability. Here, we assessed the feasibility of a flow rate measurement method that leverages time transient electrochemical behavior of a tracer that is injected directly into a medium (the electrochemical signal caused due to the tracer injectate will be diluted by the continued flow of the medium and the time response of the current—the electrodilution curve—will depend on the flow rate of the medium). In an experimental flow loop apparatus equipped with an electrochemical cell, we used the AC voltammetry technique and tested the feasibility of electrodilution-based measurement of the flow rate using two mediums—pure water and anticoagulated blood—with 0.9 wt% saline as the injectate. The electrodilution curve was quantified using three metrics—change in current amplitude, total time, and change in the total charge for a range of AC voltammetry settings (peak voltages and frequencies). All three metrics showed an inverse relationship with the flow rate of water and blood, with the strongest negative correlation obtained for change in current amplitude. The findings are a proof of concept for the electrodilution method of the flow rate measurement and offer the potential for physiological fluid flow rate measurement in vivo.

Modern trends in the design of modules of national standards for units of volume fluid flow rate (volume) in the range from 10–5 to 103 ml/min

2021 ◽  
pp. 32-41
Author(s):  
Rustam Rashidovich Tukhvatullin ◽  
Alexey Valentinovich Shchelchkov
Keyword(s):  
Fluid Flow ◽  
Flow Rate ◽  
National Standards ◽  
Operating Characteristics ◽  
Flow Rates ◽  
Sources Of Uncertainty ◽  
Liquid Evaporation ◽  
Weighing Method ◽  
Liquid Mass Flow Rate ◽  
Dynamic Weighing

In the context of the needs of the leading sectors of the world economy, the current state of metrological support for measuring units of mass and volume of a liquid in a flow, mass and volume flow rates of a liquid in the range of micro-flow rates of 10–5–103 ml/min is considered. Based on the results of the analytical review, the main metrological and operating characteristics of national standards are presented. The basic principles of generating a fluid flow in national gravimetric and volumetric standards when measuring the mass and volume of a fluid by the dynamic weighing method have been determined. Constructive solutions and principles of operation of key modules of national standards are considered. Methods for filling a liquid into a storage tank and designs of storage tanks are determined, taking into account the minimization of the effect of liquid evaporation, the influence of capillary force and buoyancy. The main sources of uncertainty in measuring the mass and volume of a liquid by the dynamic weighing method and methods for minimizing these uncertainties are considered. A modified model of dynamic measurement of liquid mass flow rate is proposed, taking into account the main sources of uncertainty. A comparative assessment of the influence of sources of uncertainty on the metrological characteristics of national standards is presented.

Assessment of Current Continuous Hemofiltration Systems and Development of a Novel Accurate Fluid Management System for Use in Extracorporeal Membrane Oxygenation

2008 ◽  
Vol 2 (3) ◽  
Author(s):  
Philippe Sucosky ◽  
Lakshmi P. Dasi ◽  
Matthew L. Paden ◽  
James D. Fortenberry ◽  
Ajit P. Yoganathan
Keyword(s):  
Fluid Flow ◽  
Extracorporeal Membrane Oxygenation ◽  
Flow Rate ◽  
Fluid Balance ◽  
Management System ◽  
Fluid Management ◽  
Flow Rates ◽  
Fluid Removal ◽  
Replacement Fluid ◽  
Membrane Oxygenation

Extracorporeal membrane oxygenation (ECMO) with a renal replacement therapy such as continuous venovenous hemofiltration (CVVH) provides life-saving temporary heart and lung, and renal support in pediatric and neonatal intensive care units. However, studies have shown that this approach may be hampered due to the potentially inaccurate fluid delivery∕drainage of current intravenous (IV) fluid pumps, creating potential for excessive fluid removal and undesired degrees of dehydration. We present a simple and novel accurate fluid management system capable of working against the high volume flow and pressures typically seen in patients on ECMO. The accuracy of the in-line system implemented at Children’s Healthcare of Atlanta at Egleston was assessed experimentally. The data assisted in the development of a novel automated and accurate fluid management system that functions based on a conservation of volume approach to limit the inaccuracies observed in typical clinical implementations of CVVH. IV pump accuracy measurements demonstrated a standard error in net ultrafiltrate volume removed from the patient of up to 848.5±156ml over a period of 24h, supporting previous observations of patient’s dehydration during the course of a combined ECMO-CVVH treatment and justifying the need for a new fluid management system. The innovative design of the new device is expected to achieve either a perfect or controlled negative fluid balance between the ultrafiltrate and replacement fluid flow rates. Perfect fluid balance is achieved by imposing an identical displacement on two pistons, one delivering replacement fluid to the circuit and the other draining ultrafiltrate from the hemofilter. Fluid removal is managed via a second syringe-pump system that reduces the net replacement fluid flow rate with respect to the ultrafiltration flow rate. The novel fluid management system described in this paper is expected to provide an effective method to control precisely fluid flow rates in patients on ECMO. Therefore, this device could potentially improve the efficacy of ECMO therapy and constitute a safe and effective way of reducing fluid overload in patients with cardiorespiratory failure.

scholarly journals Experimental Study of The Influence of Fluid Flow Rate on The Risk of Rock Destruction

2021 ◽  
Author(s):  
Sudad H Al-Obaidi
Keyword(s):  
Fluid Flow ◽  
Flow Rate ◽  
Design Flow ◽  
Fluid Flow Rate ◽  
Reservoir Properties ◽  
Rock Destruction ◽  
Flow Rates ◽  
Wide Range ◽  
Deformation Properties ◽  
Gas Fields

The stresses acting in the vicinity of wells have a significant impact on the flow properties of the reservoir and, as a result, on the flow rate of oil wells. The magnitude of such stresses depends on the deformation properties of the rock and on the oil pressure at the bottom of the well. In this work, an attempt to study the effect of flow fields (formation flow rate, well flow rates) on rocks in near-wellbore zones was performed. For this purpose, the correlation of such indicators as the fluid flow rate and the risk of destruction of the rocks of the productive deposits of one of the gas fields were experimentally studied. The experiments were performed on chosen core samples with quite wide range of flow and volumetric reservoir properties. It was concluded that the rock samples of the productive deposits of the studied formation do not collapse under the influence of pressure gradients corresponding to the design flow rates.

Dimensioning of Spiral Heat Exchangers to Give Minimum Costs

1984 ◽  
Vol 106 (3) ◽  
pp. 633-637 ◽  
Author(s):  
A. B. Jarze˛bski
Keyword(s):  
Fluid Flow ◽  
Flow Rate ◽  
Heat Exchangers ◽  
Input Data ◽  
Heating Surface ◽  
Working Fluid ◽  
Spiral Flow ◽  
Flow Rates ◽  
Process Fluid ◽  
Minimum Costs

Simple expressions are presented for calculating approximate dimensions of spiral heat exchangers to give minimum annual cost of heating surface plus energy required to pump the fluids. The case of spiral–spiral flow is considered. Equations are derived for exchangers with and without distance holders between plate strips and for two sets of input data: (i) both volumetric fluid flow rates V1, V2 and all inlet and appropriate outlet temperatures are given; (ii) the flow rate of the process fluid V1 and the effectiveness e1 are imposed, while the flow rate of the working fluid V2 is an additional variable subject to optimization. For the latter case, appropriate optimum values of V2 can readily be found from the graphs provided.

Experimental Investigation on the Condensation Efficiency of Humid Air in a Cross-Flow Condenser

2013 ◽  
Author(s):  
Hojin Ahn ◽  
Burhan Gul ◽  
Yavuz Sahin ◽  
Onur Hartoka
Keyword(s):  
Flow Rate ◽  
Single Channel ◽  
Cross Flow ◽  
Condensation Process ◽  
Mixture Flow ◽  
Flow Rates ◽  
Cooling Flow ◽  
Cooling Air Flow ◽  
Cooling Air ◽  
Heat Released

The condensation of steam in the presence of air has been investigated experimentally in the cross-flow flat-plate single-channel condenser. In particular, the condensation efficiency which is defined by the ratio of heat released during the condensation process (the amount of latent heat) to the total heat extracted from the mixture of vapor and non-condensable gas (the sum of latent and sensible heats) is examined as a function of the air-steam mixture temperature and humidity at inlet and the flow rates of the air-steam mixture and cooling air. The preliminary results are obtained with the operating condition of the air-steam mixture flow at 70°C and 80, 85 and 90% relative humidity at inlet. The most notable result is that the condensation efficiency evidently decreases with the increase of the cooling air flow rate. With both mixture and cooling flow rates kept constant, the condensation efficiency increases, as expected, with the increasing air-steam mixture humidity at the inlet. On the other hand, the air-steam mixture flow rate appears to have little effect on the condensation efficiency.

scholarly journals The effect of the intermediate fluid flow rate on the system performance in the closed circuit applications of the solar collector

2019 ◽  
pp. 472-472 ◽  
Author(s):  
Hasan Yildizhan ◽  
Taqi Cheema ◽  
Mecit Sivrioğlu
Keyword(s):  
Heat Transfer ◽  
Fluid Flow ◽  
Flow Rate ◽  
Solar Collector ◽  
Closed Loop ◽  
Closed Circuit ◽  
Working Fluid ◽  
Solar Collectors ◽  
Flow Rates ◽  
Energy And Exergy

Solar collector water heating system use solar thermal energy to provide hot water for domestic and industrial use. These systems are operated either as open-loop or closed-loop flow circuit. The former loop systems are not recommended for the cold climates having water freezing problem. Although previous studies on solar collectors have used closed-loop operation with water as the working fluid; however, it must have high boiling and low freezing points for the colder regions and thus arises the need for antifreeze mixtures of water. Another solution to the same problem is the use of heat transfer oil as intermediate working fluids. In the present study, the energy and exergy analysis of a boiler supported vacuum tube solar collector system working with closed-loop in different working fluid flow rates have been performed and evaluated. Heat transfer oil has been used as an intermediate working fluid in the closed loop system at different flow rates of 0.277 kg/s, 0.383 kg/s, 0.494 kg/s. The results show that the collector temperature difference as well as the outlet temperature decrease; however, the collector inlet temperature increases by increasing the flow rate. Moreover, with the increase in flow rate, it was ascertained that the energy and exergy efficiency of the system and the collectors increase. The main finding of the present study is that the intermediate fluid used in the closed-circuit operation of the solar collectors has a direct effect on the energy and exergy efficiency of the system.

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