Estimation of Hydraulic Gradient for a Transport Pipeline

2020 ◽  
Vol 143 (3) ◽  
Author(s):  
J. Rojas ◽  
C. Verde ◽  
L. Torres
Keyword(s):  
Computational Models ◽  
Hydraulic Gradient ◽  
Fluid Viscosity ◽  
Test Apparatus ◽  
Gradient Estimation ◽  
Environmental Disturbances ◽  
Order Polynomial ◽  
Fluid Properties ◽  
On Line ◽  
Pipe Roughness

Abstract This work deals with the hydraulic gradient estimation in real-time of a transport pipeline computational model by considering a slightly compressible fluid and slightly deformable conduit walls. Since the hydraulic gradient (J(Q)) caused by the friction phenomenon in a pipeline plays an important role in the system's behavior, and this function is affected by fluid properties' deviations, environmental disturbances and conduit deteriorations, it is proposed that the on-line estimation of J(Q) could be part of a monitoring system. The proposition can be applied to obtain computational models of a line with a junction and assumes only measurements of pressure and flow rate at the ends of the conduit and the junction outflow. The generic form of the gradient function J(Q) is a second-order polynomial with coefficients that involve indirectly pipe roughness, the transversal area of the conduit, fluid viscosity and elements connected to the line. The extended Kalman filter (EKF) is applied to estimate the coefficients of the function J(Q). As a test apparatus, a 163 m long hydraulic pipeline is used. Diverse experiments show the usefulness of the on-line estimation of J(Q) for monitoring and simulation tasks where computational models are necessary.

Non-Isothermal Peristaltic Flow of Newtonian Fluids in a Circular Tube

2009 ◽  
Author(s):  
M. S. Yun ◽  
B. P. Huynh
Keyword(s):  
Reynolds Number ◽  
Flow Pattern ◽  
Circular Tube ◽  
Pressure Change ◽  
Peristaltic Flow ◽  
Isothermal Flow ◽  
Newtonian Fluids ◽  
Fluid Viscosity ◽  
Fluid Properties ◽  
Isothermal Case

Non-isothermal peristaltic flow of Newtonian fluids in a circular tube is investigated numerically, using a commercial Computational Fluid Dynamics (CFD) software package. Simulation is performed over a range of Reynolds-number values, up to 1000. Temperature affects the flow field via fluid viscosity, which is assumed to decrease exponentially with temperature. Other fluid properties are assumed to be constant, and are similar to those of an oil. Allowing for temperature effects alters significantly the flow pattern and reduces pressure change. In the crest region, recirculation appears in non-isothermal flow at a much smaller Reynolds number Re than in isothermal flow. Influence of the Reynolds number itself is also reduced significantly, such that the flow pattern changes very little with increasing Re, in contrast to the isothermal case. Similarly, in non-isothermal flow, flow pattern is unchanged at different flow rate. This is also in contrast to the isothermal situation.

Thermodynamic Properties of Fluids

1997 ◽  
Author(s):  
David Jon Furbish
Keyword(s):  
Mechanical Energy ◽  
Fluid Pressure ◽  
Fluid Flows ◽  
Thermal Conditions ◽  
Fluid Viscosity ◽  
Frozen Ground ◽  
Patterned Ground ◽  
Fluid Behavior ◽  
Fluid Properties ◽  
Convective Motions

Fluid behavior in many geological problems is strongly influenced by extant thermal conditions and flow of heat. Recall, for example, that the coefficient A in Glen’s law for ice (3.40) varies over three orders of magnitude with a change in temperature of 50 °C. The effect of this is to strongly modulate the rate of ice deformation for a given level of stress. Recall further that we introduced several fluid properties—fluid compressibility, for example—where we asserted that our purely mechanical developments were incomplete inasmuch as they did not treat effects of varying temperature. The reasons for this will become clear in this chapter, including why it is difficult to maintain isothermal conditions when the pressure of a fluid is changing. In addition, many geological problems involve fluid flows that are induced by effects of variations in thermal conditions over time and space. These include buoyancy-driven convective motions that arise from variations in fluid density associated with variations in temperature (Chapter 16). Specific examples include convective overturning in a magma chamber, which can significantly influence how crystallizing minerals are distributed; convective circulations of water and chemical solutions in a sedimentary basin, which can influence where rock materials are dissolved and where they are precipitated as cements within pores; and convective circulation of water within the active layer above seasonally frozen ground, which may influence where patterned ground develops in periglacial environments. These processes, and viscous flows in general, invariably involve conversions of mechanical energy to heat, or vice versa. So in considering problems involving heat energy, we should recall from introductory chemistry and physics that such conversions can involve work performed on the fluid or its surroundings, and anticipate that the effects of this ought be manifest in fluid behavior. This chapter, then, is concerned with fluid pressure, temperature, and density, and how these variables are related to heat, mechanical energy, and work. We will note in digressions how these macroscopic concepts, like fluid viscosity, often have clear interpretations at a molecular scale based on kinetic theory of matter.

Development of On-Line Sensors for Automated Measurement of Drilling Fluid Properties

2014 ◽  
Author(s):  
Sergio Magalhaes ◽  
Claudia Miriam Scheid ◽  
Luis Americo Calcada ◽  
Mauricio Folsta ◽  
Andre Leibsohn Martins ◽  
...  
Keyword(s):  
Drilling Fluid ◽  
Automated Measurement ◽  
Fluid Properties ◽  
On Line

scholarly journals Boundary Layer Flow and Heat Transfer with Variable Fluid Properties on a Moving Flat Plate in a Parallel Free Stream

2012 ◽  
Vol 2012 ◽  
pp. 1-10 ◽  
Author(s):  
Norfifah Bachok ◽  
Anuar Ishak ◽  
Ioan Pop
Keyword(s):  
Heat Transfer ◽  
Boundary Layer ◽  
Flat Plate ◽  
Boundary Layer Flow ◽  
Free Stream ◽  
Fluid Viscosity ◽  
Flow And Heat Transfer ◽  
Variable Fluid Properties ◽  
Fluid Properties ◽  
Layer Flow

The steady boundary layer flow and heat transfer of a viscous fluid on a moving flat plate in a parallel free stream with variable fluid properties are studied. Two special cases, namely, constant fluid properties and variable fluid viscosity, are considered. The transformed boundary layer equations are solved numerically by a finite-difference scheme known as Keller-box method. Numerical results for the flow and the thermal fields for both cases are obtained for various values of the free stream parameter and the Prandtl number. It is found that dual solutions exist for both cases when the fluid and the plate move in the opposite directions. Moreover, fluid with constant properties shows drag reduction characteristics compared to fluid with variable viscosity.

scholarly journals Viscous fluid flow between plane walls in presence of temperature gradient

2021 ◽  
pp. 26-38
Author(s):  
Алексей Олегович Сыромясов ◽  
Татьяна Вячеславовна Меньшакова
Keyword(s):  
Temperature Gradient ◽  
Viscous Fluid ◽  
Fluid Velocity ◽  
Asymptotic Methods ◽  
Temperature Drop ◽  
Fluid Viscosity ◽  
Slow Flow ◽  
First Order ◽  
Order Polynomial ◽  
Isothermal Case

В статье изучается медленный поток вязкой несжимаемой жидкости, ограниченной двумя параллельными плоскостями. Течение вызвано либо движением одной плоскости относительно другой, либо перепадом давления вдоль двух неподвижных плоскостей. Предполагается, что вязкость жидкости есть многочлен первой степени от температуры, а в рассматриваемом объеме поддерживается постоянный градиент этой величины. Это приводит к возмущению потока по сравнению с изотермическим случаем. Асимптотическими методами исследована зависимость возникающих искажений от типа потока и взаимной ориентации потока и градиента температуры. При этом перепад температуры на расстоянии, равном зазору между плоскостями, считается малым. Показано, что эти искажения могут вноситься как в скорость, так и в давление жидкости. В последнем случае при наличии в жидкости взвеси возможно возникновение дополнительной подъемной силы или силы тяги, действующей на инородные частицы. Slow flow of incompressible viscous fluid confined by two parallel planes is studied in the paper. The flow is caused either by motion of one plane with respect to another or by pressure drop along the planes. It is supposed that fluid viscosity is the first-order polynomial of temperature and that its gradient is constant in the entire domain under study. These two reasons cause the flow to be disturbed (compared with isothermal case). Dependence of these disturbances on the type of flow and on the orientation of temperature gradient with respect to the flow is investigated by asymptotic methods. Temperature drop on distances equal to the gap between planes is supposed to be small during the investigation. It is shown that both fluid velocity and pressure may be disturbed. In the last case additional lift or drag force may act on the alien particles suspended in the fluid (if it contains any).

An Experimental Model Investigation of the Opening of a Collapsed Untethered Pulmonary Airway

1995 ◽  
Vol 117 (3) ◽  
pp. 245-253 ◽  
Author(s):  
Matthew L. Perun ◽  
Donald P. Gaver
Keyword(s):  
Surface Tension ◽  
Steady State ◽  
Structural Characteristics ◽  
Stable Steady State ◽  
Effective Diameter ◽  
Fluid Viscosity ◽  
Two Dimensional ◽  
Fluid Properties ◽  
Wall Deformation ◽  
Fluid Film Thickness

We developed an essentially two-dimensional planar benchtop model of an untethered collapsed airway to investigate the influence of fluid properties (viscosity, μ and surface tension, γ) and the structural characteristics (effective diameter, D, longitudinal tension, T, and fluid film thickness, H) on airway reopening. This simplified model was used to quantify the relationship between wall deformation and meniscus curvature during reopening. We measured the pressure (P) required to move the meniscus at a constant velocity (U), and found the dimensionless post-startup pressure (PD/γ) increased monotonically with the capillary number (Ca = μU/γ). Startup pressures depend on the fluid viscosity and piston acceleration, and may significantly increase reopening pressures. Consistently stable steady-state pressures existed when Ca > 0.5. D was the most dominant structural characteristic, which caused an increase in the post-startup pressure (P) for a decrease in D. An increase in H caused a slight decrease in the reopening pressure, but a spatial variation in H resulted in only a transient increase in pressure. T did not significantly affect the reopening pressure. From our planar two-dimensional experiments an effective yield pressure of 3.69 γ/D was extrapolated from the steady-state pressures. Based on these results, we predicted airway pressures and reopening times for axisymmetrically collapsed airways under various disease states. These predictions indicate that increasing surface tension (as occurs in Respiratory Distress Syndrome) increases the yield pressure necessary to reopen the airways, and increasing viscosity (as in cystic fibrosis) increases the time to reopen once the yield pressure has been exceeded.

Hydraulic Fluid Viscosity Selection for Improved Fuel Economy

2008 ◽  
Author(s):  
Paul Michael ◽  
Steven N. Herzog
Keyword(s):  
Power Systems ◽  
Fuel Economy ◽  
Major Influence ◽  
Fluid Viscosity ◽  
Hydraulic Fluid ◽  
Hydraulic Equipment ◽  
Fluid Properties ◽  
Selection For ◽  
Fluid Power Systems ◽  
The Relationship

Fluid properties have a major influence upon the energy efficiency of hydraulic equipment. The relationship between hydraulic fluid viscosity, shear stability and system fuel economy has been studied. New viscosity selection guidelines for hydraulic pumps and motors are proposed. These guidelines provide a means for improving the efficiency of fluid power systems.

scholarly journals Performance Prediction of a Turbodrill Based on the Properties of the Drilling Fluid

Machines ◽  
2021 ◽  
Vol 9 (4) ◽  
pp. 76
Author(s):  
Delong Zhang ◽  
Yu Wang ◽  
Junjie Sha ◽  
Yuguang He
Keyword(s):  
High Temperature ◽  
Performance Prediction ◽  
Drilling Fluid ◽  
High Viscosity ◽  
High Density ◽  
Fluid Viscosity ◽  
Two Phase ◽  
Geometry Model ◽  
Multi Stage ◽  
Fluid Properties

High-temperature geothermal well resource exploration faces high-temperature and high-pressure environments at the bottom of the hole. The all-metal turbodrill has the advantages of high-temperature resistance and corrosion resistance and has good application prospects. Multistage hydraulic components, consisting of stators and rotors, are the key to the turbodrill. The purpose of this paper is to provide a basis for designing turbodrill blades with high-density drilling fluid under high-temperature conditions. Based on the basic equation of pseudo-fluid two-phase flow and the modified Bernoulli equation, a mathematical model for the coupling of two-phase viscous fluid flow with the turbodrill blade is established. A single-stage blade performance prediction model is proposed and extended to multi-stage blades. A Computational Fluid Dynamics (CFD) model of a 100-stage turbodrill blade channel is established, and the multi-stage blade simulation results for different fluid properties are given. The analysis confirms the influence of fluid viscosity and fluid density on the output performance of the turbodrill. The research results show that compared with the condition of clear water, the high-viscosity and high-density conditions (viscosity 16 mPa∙s, density 1.4 g/cm3) will increase the braking torque of the turbodrill by 24.2%, the peak power by 19.8%, and the pressure drop by 52.1%. The results will be beneficial to the modification of the geometry model of the blade and guide the on-site application of the turbodrill to improve drilling efficiency.

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