Experimental Investigation of Large Particle Slurry Transport in Vertical Pipes With Pulsating Flow

2020 ◽  
Author(s):  
Sotaro Masanobu ◽  
Satoru Takano ◽  
Shigeo Kanada ◽  
Masao Ono ◽  
Hiroki Sasagawa
Keyword(s):  
Pressure Loss ◽  
Prediction Method ◽  
Internal Flow ◽  
Glass Beads ◽  
Solid Particles ◽  
Pulsating Flow ◽  
Massive Sulfides ◽  
Pressure Losses ◽  
Transport Experiment ◽  
Slurry Transport

Abstract For subsea mining, it is important to predict the pressure loss in oscillating pipes with pulsating flow for the safe and reliable operation of ore lifting. In the present paper, the authors focused on the pulsating internal flow in static vertical pipe and carried out slurry transport experiment to investigate the effects of flow fluctuation on the pressure loss. The alumina beads and glass beads were used as the solid particles in the experiment, and the fluctuating periods and amplitudes of pulsating water flow were varied. The time-averaged pressure losses calculated by the prediction method for the steady flow proposed in the past by the authors agreed well with the experimental ones. As for the fluctuating component of pressure loss, the calculation results using the quasi-steady expression of a mixture model were compared with the experimental data. The calculated results were different from experimental ones for alumina beads of which densities are almost same as those of the ores of Seafloor Massive Sulfides. It suggests that the expression is insufficient to predict the pressure loss for heavy solid particles. The calculated ones, however, provided those in the safety side. On the other hand, the calculated results for light solid particles such as glass beads agreed well with the experimental ones. It means that the expression would be applicable to the prediction of pressure loss for the mining of manganese nodules which are lighter than the ores of Seafloor Massive Sulfides.

Experimental Investigation of Large Particle Slurry Transport in Vertically Oscillating Pipe for Subsea Mining

2021 ◽  
Author(s):  
Sotaro Masanobu ◽  
Satoru Takano ◽  
Shigeo Kanada ◽  
Masao Ono
Keyword(s):  
Mixture Model ◽  
Pressure Loss ◽  
Prediction Method ◽  
Axial Direction ◽  
Hydraulic Gradient ◽  
Solid Particles ◽  
Homogeneous Mixture ◽  
Pipe Model ◽  
Slurry Transport ◽  
Homogeneous Mixture Model

Abstract For subsea mining, it is important to predict the pressure loss in oscillating pipes for the safe and reliable operation of ore lifting as well as the design of lifting system. In the present paper, the authors focused on the internal flow in vertical lifting pipe oscillating in the axial direction and carried out slurry transport experiment to investigate the effects of pipe oscillation on the pressure loss. The spherical alumina beads and glass beads were used as the solid particles in the experiment, and the oscillating periods and amplitudes of pipe model as well as the solid concentrations and the mean slurry velocities were varied. The time-averaged components of hydraulic gradient calculated by the prediction method for the steady flow proposed in the past by the authors agreed well with the experimental ones. As for the fluctuating components of hydraulic gradient, the calculation results using a homogeneous mixture model were compared with the experimental data. The comparison result indicated that the homogeneous mixture model would be applicable to the prediction of pressure loss in the vertical pipe oscillating in the axial direction.

Influence of Pulsating Flow on Turbine Performance Investigated by DES and PIV

2018 ◽  
Author(s):  
Yohei Nakamura ◽  
Manato Chinen ◽  
Masamichi Sakakibara ◽  
Kazuyoshi Miyagawa
Keyword(s):  
Pressure Loss ◽  
Total Pressure ◽  
Internal Flow ◽  
Pulsating Flow ◽  
Total Pressure Loss ◽  
Operating Point ◽  
Pulsation Frequency ◽  
Flow Conditions ◽  
Experimental Apparatus ◽  
Loss Mechanisms

Recently, the downsizing of engine using turbocharger attracts more and more attention. Generally speaking, a turbocharger is usually designed based on its steady performance curve. However, the operating point of a turbocharger turbine does not match the steady operating point: instead it shows hysteresis behavior because of the pulsating flow generated by the engine valves. Unfortunately, turbine efficiency drops under pulsating flow conditions, but the loss mechanisms of the turbine under these conditions are not understood. Internal flow measurements under pulsating flow are actually very difficult. In this study, the internal flow under pulsating conditions was measured using a high speed PIV (Particle Image Velocimetry) system. The loss mechanisms were investigated by experimental investigation and computational fluid dynamics (CFD). The instantaneous pressure, velocity and torque were measured using a turbine experimental apparatus at WASEDA University. To generate the pulsating flow, a pulse generator was placed upstream of the turbine: a rotational disk with holes that only lets the flow through periodically. The pulsating frequency could be changed freely by changing the rotational speed of the disk. The visualization using PIV was performed at a frequency of 1 kHz at the turbine outlet. Many fine vortices which rotate in various directions were observed under pulsating flow. Such vortices mix in the exhaust diffuser and under low frequency flow, mixing of vortices took a long time. It was observed that one loss mechanism under unsteady conditions is the mixing of vortices at the turbine outlet. CFD was performed using ANSYS-CFX, with approximately 10 million nodes. Turbulent flows were treated by using the Reynolds-averaged Navier-Stokes (RANS) and Detached Eddy Simulation (DES) with the SST k-ω turbulence model. It was confirmed that the wheel and exhaust diffuser total pressure loss under pulsating flow was higher under steady flow conditions. In addition, the total pressure loss is proportional to the flow pulsation frequency. The analysis with DES agreed with the PIV results qualitatively. On the other hand, the analysis with RANS could not simulate the flow pattern at the turbine outlet.

scholarly journals Development of a Regenerator for an Automotive Gas Turbine Engine

1992 ◽  
Author(s):  
Junichi Sayama ◽  
Teru Morishita
Keyword(s):  
Velocity Distribution ◽  
Gas Turbine ◽  
Pressure Loss ◽  
Prediction Method ◽  
Gas Turbine Engine ◽  
Core Size ◽  
Turbine Engine ◽  
Pressure Losses ◽  
The Core ◽  
Core Matrix

It is vital to accurately estimate the temperature effectiveness and pressure loss of the regenerator when designing a gas turbine engine because these characteristics basically determine the size, weight, and fuel consumption of the regenerative gas turbine engine. In operation of an actual engine, regenerators often fail to attain the characteristics predicted by conventional methods, because there are many performance-reducing irregularities such as the non-uniform velocity distribution of gases flowing into the core. In this paper, a prediction method that is based on data from actual engine tests is examined as a way to predict regenerator temperature effectiveness and pressure losses when there are causes for deterioration of these characteristics. This method resulted in a system, taking the deterioration of these characteristics into consideration as they occur in an actual engine, that represents temperature effectiveness and pressure loss as the function of core specifications such as the core size and the core matrix. This prediction method was then used to predict the regenerator characteristics of actual engines with more than satisfactory results (The accuracy is ±1.25% for temperature effectiveness and ±4% for pressure loss).

Pressure Loss Due to Hydraulic Transport of Large Solid Particles in Vertical Pipes Under Pulsating Flow Conditions

2021 ◽  
Vol 143 (6) ◽  
Author(s):  
Sotaro Masanobu ◽  
Satoru Takano ◽  
Shigeo Kanada ◽  
Masao Ono
Keyword(s):  
Pressure Loss ◽  
Solid Particles ◽  
Hydraulic Transport ◽  
Vertical Pipe ◽  
Mining System ◽  
Mixture Flow ◽  
Pressure Losses ◽  
Proposed Model ◽  
Calculation Results ◽  
The One

Abstract It is important to predict the pressure loss due to hydraulic transport of large solid particles for the design of subsea mining system. The mixture flow in the lifting pipe is expected to be unsteady in the actual mining system. The authors develop the one-dimensional mathematical model to predict the pressure loss of pulsating mixture flow in a static vertical pipe assuming that the flow in the pipe is fully developed. The experiment on hydraulic transport of solid particles was carried out to obtain the data for the investigation of the effects of flow fluctuation on pressure loss in a static vertical pipe. In the experiment, alumina beads and glass beads were used as solid particles, and the experimental parameters were mixture velocity, solid concentration, pulsating period, and pulsating amplitude. The proposed model was validated by a comparison with experimental data. Furthermore, we calculated the pressure losses due to hydraulic transports of polymetallic sulfide ores and manganese nodules using the proposed model. The calculation results showed that the fluctuating component in pulsating mixture flow should be considered for the design of lifting system and that the homogeneous mixture model could not be applied to the prediction of the pressure loss unless the mixture concentration is low and the pulsating period is short.

Experimental Studies of Pressure Loss for Large Particle Slurry Transport in Oscillated Pipe for Subsea Mining

2017 ◽  
Author(s):  
Satoru Takano ◽  
Sotaro Masanobu ◽  
Shigeo Kanada ◽  
Masao Ono ◽  
Motoki Araki ◽  
...  
Keyword(s):  
Flow Rate ◽  
Pressure Loss ◽  
Large Particle ◽  
Experimental Studies ◽  
Vertical Direction ◽  
Solid Particles ◽  
Experimental Conditions ◽  
Scaled Model ◽  
Riser Pipe ◽  
Slurry Transport

Subsea minerals exist in the deep water within Japanese exclusive economic zone. Development of slurry pump passing large particles is required for lifting ore. In design of slurry pump, it is significant to estimate the pressure loss in a riser pipe for large particle slurry transport. Therefore the authors have been studied the slurry flow model for large particle slurry transport. In addition, the authors developed the model for the static pipe including the inclined configurations. Since the lifting pipe will be oscillated due to the connected ship motion and VIV (Vortex Induced Vibration), the authors conducted the scaled model experiment to investigate the effects of pipe oscillation on the pressure loss. The model scale was 1/8. Alumina beads and glass beads were used as solid particles in the experiment. The pipe was vertical, and oscillated in horizontal or vertical direction. The experimental results showed that the horizontal and vertical oscillation had little influence on the static pressure loss in most of the experimental conditions. However the influence was observed for the horizontally oscillating pipe in the low slurry velocity and short oscillation period condition. On the other hand, the significant fluctuation components of pressure loss and flow rate were observed in vertically oscillating pipe. The results also indicated that the density of slurry and amplitude of oscillation had influence on the fluctuation components of pressure loss and flow rate but the particle diameters had little influence on them.

Development of a Regenerator for an Automotive Gas Turbine Engine

1993 ◽  
Vol 115 (2) ◽  
pp. 424-431 ◽  
Author(s):  
J. Sayama ◽  
T. Morishita
Keyword(s):  
Velocity Distribution ◽  
Gas Turbine ◽  
Pressure Loss ◽  
Prediction Method ◽  
Gas Turbine Engine ◽  
Core Size ◽  
Turbine Engine ◽  
Pressure Losses ◽  
The Core ◽  
Core Matrix

It is vital to estimate the temperature effectiveness and pressure loss of the regenerator accurately when designing a gas turbine engine because these characteristics basically determine the size, weight, and fuel consumption of the regenerative gas turbine engine. In operation of an actual engine, regenerators often fail to attain the characteristics predicted by conventional methods, because there are many performance-reducing irregularities such as the nonuniform velocity distribution of gases flowing into the core. In this paper, a prediction method that is based on data from actual engine tests is examined as a way to predict regenerator temperature effectiveness and pressure losses when there are causes for deterioration of these characteristics. This method resulted in a system, taking the deterioration of these characteristics into consideration as they occur in an actual engine, that represents temperature effectiveness and pressure loss as the function of core specifications such as the core size and the core matrix. This prediction method was then used to predict the regenerator characteristics of actual engines with more than satisfactory results (the accuracy is ±1.25 percent for temperature effectiveness and ±4 percent for pressure loss).

Computation and Experimental Results of Wear in a Slurry Pump Impeller

1986 ◽  
Vol 200 (6) ◽  
pp. 439-445 ◽  
Author(s):  
K Ahmad ◽  
R C Baker ◽  
A Goulas
Keyword(s):  
Computer Program ◽  
Calculation Method ◽  
Prediction Method ◽  
Internal Flow ◽  
Leading Edge ◽  
Solid Particles ◽  
Experimental Results ◽  
Pressure Side ◽  
Pump Impeller ◽  
Good Agreement

Using a computer program to obtain the internal flow in a pump impeller, the trajectories of solid particles were found and used to predict the regions of wear within the pump. In order to assess the validity of this prediction method tests were undertaken to obtain the erosion-prone areas of the pump by observing the erosion of layers of paint on the pump impeller. There was good agreement but the level of erosion was underestimated by the predictions. The calculation method and the use of paint to obtain wear patterns were both promising methods. Maximum wear in this case was near the leading edge on the pressure side and on the back shroud in the eye of the impeller.

Modeling of pressure losses on friction in three-layer laminar flows

2003 ◽  
Vol 3 ◽  
pp. 208-219
Author(s):  
A.M. Ilyasov
Keyword(s):  
Pressure Loss ◽  
Gas Flow ◽  
Mutual Influence ◽  
Fluid Model ◽  
Immiscible Liquid ◽  
Laminar Flows ◽  
Pressure Losses ◽  
Flow Parameters ◽  
Interphase Boundaries ◽  
Closing Relations

In this paper we propose a model for determining the pressure loss due to friction in each phase in a three-layer laminar steady flow of immiscible liquid and gas flow in a flat channel. This model generalizes an analogous problem for a two-layer laminar flow, proposed earlier. The relations obtained in the final form for the pressure loss due to friction in liquids can be used as closing relations for the three-fluid model. These equations take into account the influence of interphase boundaries and are an alternative to the approach used in foreign literature. In this approach, the wall and interphase voltages are approximated by the formulas for a single-phase flow and do not take into account the mutual influence of liquids on the loss of pressure on friction in phases. The distribution of flow parameters in these two models is compared.

scholarly journals Turbulence model performance for ventilation components pressure losses

2021 ◽  
Author(s):  
Karsten Tawackolian ◽  
Martin Kriegel
Keyword(s):  
Reynolds Number ◽  
Turbulence Model ◽  
Pressure Loss ◽  
Low Reynolds Number ◽  
Turbulence Models ◽  
Reynolds Numbers ◽  
Test Case ◽  
Pressure Losses ◽  
Loss Coefficients ◽  
Near Wall

AbstractThis study looks to find a suitable turbulence model for calculating pressure losses of ventilation components. In building ventilation, the most relevant Reynolds number range is between 3×104 and 6×105, depending on the duct dimensions and airflow rates. Pressure loss coefficients can increase considerably for some components at Reynolds numbers below 2×105. An initial survey of popular turbulence models was conducted for a selected test case of a bend with such a strong Reynolds number dependence. Most of the turbulence models failed in reproducing this dependence and predicted curve progressions that were too flat and only applicable for higher Reynolds numbers. Viscous effects near walls played an important role in the present simulations. In turbulence modelling, near-wall damping functions are used to account for this influence. A model that implements near-wall modelling is the lag elliptic blending k-ε model. This model gave reasonable predictions for pressure loss coefficients at lower Reynolds numbers. Another example is the low Reynolds number k-ε turbulence model of Wilcox (LRN). The modification uses damping functions and was initially developed for simulating profiles such as aircraft wings. It has not been widely used for internal flows such as air duct flows. Based on selected reference cases, the three closure coefficients of the LRN model were adapted in this work to simulate ventilation components. Improved predictions were obtained with new coefficients (LRNM model). This underlined that low Reynolds number effects are relevant in ventilation ductworks and give first insights for suitable turbulence models for this application. Both the lag elliptic blending model and the modified LRNM model predicted the pressure losses relatively well for the test case where the other tested models failed.

Annular Frictional Pressure Losses During Drilling—Predicting the Effect of Drillstring Rotation

2014 ◽  
Vol 136 (3) ◽  
Author(s):  
Arild Saasen
Keyword(s):  
Rheological Properties ◽  
Pressure Loss ◽  
Drilling Fluid ◽  
Axial Flow ◽  
Drilling Fluids ◽  
Unstable Flow ◽  
Pressure Losses ◽  
Shear Dependent Viscosity ◽  
Water Based ◽  
Dependent Viscosity

Controlling the annular frictional pressure losses is important in order to drill safely with overpressure without fracturing the formation. To predict these pressure losses, however, is not straightforward. First of all, the pressure losses depend on the annulus eccentricity. Moving the drillstring to the wall generates a wider flow channel in part of the annulus which reduces the frictional pressure losses significantly. The drillstring motion itself also affects the pressure loss significantly. The drillstring rotation, even for fairly small rotation rates, creates unstable flow and sometimes turbulence in the annulus even without axial flow. Transversal motion of the drillstring creates vortices that destabilize the flow. Consequently, the annular frictional pressure loss is increased even though the drilling fluid becomes thinner because of added shear rate. Naturally, the rheological properties of the drilling fluid play an important role. These rheological properties include more properties than the viscosity as measured by API procedures. It is impossible to use the same frictional pressure loss model for water based and oil based drilling fluids even if their viscosity profile is equal because of the different ways these fluids build viscosity. Water based drilling fluids are normally constructed as a polymer solution while the oil based are combinations of emulsions and dispersions. Furthermore, within both water based and oil based drilling fluids there are functional differences. These differences may be sufficiently large to require different models for two water based drilling fluids built with different types of polymers. In addition to these phenomena washouts and tool joints will create localised pressure losses. These localised pressure losses will again be coupled with the rheological properties of the drilling fluids. In this paper, all the above mentioned phenomena and their consequences for annular pressure losses will be discussed in detail. North Sea field data is used as an example. It is not straightforward to build general annular pressure loss models. This argument is based on flow stability analysis and the consequences of using drilling fluids with different rheological properties. These different rheological properties include shear dependent viscosity, elongational viscosity and other viscoelastic properties.

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