Preparation of Ferrofluid Sealing Ship Stern Shaft and Design of its Seal Structure

2011 ◽  
Vol 486 ◽  
pp. 167-170
Author(s):  
En Xia Yang ◽  
He Ping Liu ◽  
Tao Qin
Keyword(s):  
Magnetic Field ◽  
Pressure Drop ◽  
Chemical Method ◽  
Magnetic Particles ◽  
Experimental Results ◽  
Magnetic Intensity ◽  
Pressure Drops ◽  
Water Based ◽  
Additional Magnetic Field

Ferrofluid is prepared with the chemical method in order to seal the ship stern shaft. Three types of ferrofluid are obtained. Their magnetic particles all are Fe3O4, but their base solutions are separately water, oil and fluorine ether oil. Experimental results show that the value of saturated magnetic intensity of oil based ferrofluid is higher than the others, and its seal performance is better. Viscosity and density of fluorine ether oil based ferrofluid are the highest. Under the effect of the additional magnetic field, the pressure drops of water or oil sealed by water based ferrofluid are all lower, but the pressure drop of water sealed by oil based ferrofluid is close to an ideal value. Therefore, it has practical value that oil based ferrofluid is used as sealing liquid of ship stern shaft.

Experiment Using a Magnetically Controlled Ferrofluid Flow in a Flatplate Laminar Flow System

2014 ◽  
Vol 896 ◽  
pp. 444-447
Author(s):  
Yi Hua Fan ◽  
Liao Yong Lou ◽  
Yu Ming Chen
Keyword(s):  
Magnetic Field ◽  
Laminar Flow ◽  
Magnetic Particles ◽  
Flow System ◽  
Experimental Results ◽  
Carrier Fluid ◽  
Field Coefficient ◽  
Coefficient Of Viscosity ◽  
Relationship Of ◽  
The Magnetic Field

The Phenomenon of a Magnetic Controlled Ferrofluid Flow in the Flat Plate Laminar Flow System is Discussed in this Paper. the Ferrofluid Flow is One Kind of Colloid Mixture, which is Composited by the Magnetic Particles, Carrier Fluid and Surfactant. its Motion is Followed the Fluid Dynamics and can be Controlled by a Magnetic Field. from the Theoretic Analysis and the Experimental Test, the Coefficient of Viscosity of the Ferrofluid Flow will be Affected by the Magnetic Field. Thus, an Experimental Rig is Built to Test the Influences of the Gap of the Plate and the Strength and Direction of the Magnetic Field for Several Ferrofluid Flows with Different Dividing Rates of Volume. Experimental Results Showed that the Coefficient of Viscosity of the Ferrofluid Flow is Almost Not Upgrading in a Wide Gap Condition by the Magnetic Field, but as the Gap is Smaller, the Coefficient of Viscosity will be Promoted Obviously. Furthermore, Enhancing the Magnetic Field, it will be Increase the Coefficient of Viscosity of the Ferrofluid Flow. from the Experimental Results, the Relationship of the Magnetic Field, Coefficient of Viscosity of Ferrofluid Flow and the Carrier Fluid can be Confirmed.

Vibration Suppression Device Having Variable Inertia Mass by MR-Fluid

2011 ◽  
Author(s):  
Taichi Matsuoka
Keyword(s):  
Magnetic Field ◽  
Magnetic Particles ◽  
Vibration Suppression ◽  
Experimental Results ◽  
Inertia Force ◽  
Test Device ◽  
Piston Cylinder ◽  
New Type ◽  
Vibration Tests ◽  
Force Characteristics

Authors have proposed a new type of vibration suppression device that utilizes variable inertia mass by fluid which acts as a series inertia mass. The series inertia mass is proportional to not only square of a ratio between a diameter of a piston cylinder and a by-pass pipe, and also a density of the fluid. The resisting force characteristics in case of water or turbine oil were measured. To confirm the proposed theory and investigate effects of vibration control, vibration tests of frequency response and seismic response of one-degree-of-freedom system with the test device were carried out. The experimental results were compared with the calculated results, and the effects of vibration suppression are confirmed experimentally and theoretically. In this paper, in order to derive the effect of a variable inertia mass by using a magnet-rheological fluid, resisting force characteristics of the test device are measured in several cases of magnetic field. The orifice of the by-pass pipe can be changed in virtual, since some rare-earth magnets are installed around the by-pass pipe. It can be seen from experimental results that the inertia force is increasing as stronger magnetic fields. It is pointed out that the variable inertia mass can be derived since clustered magnetic particles in the by-pass pipe act as a virtual orifice under strong magnetic field. The relation between magnetic flux and variable inertia mass are estimated experimentally.

Flow Characteristics and Frictional Pressure Drops of Gas-Liquid Two-Phase Flow in Mini-Micro Pipes and at Vena Contract and Expansion

2007 ◽  
Author(s):  
Hiroyasu Ohtake ◽  
Hideyasu Ohtaki ◽  
Yasuo Koizumi
Keyword(s):  
Pressure Drop ◽  
Flow Pattern ◽  
Two Phase Flow ◽  
Liquid Velocity ◽  
Flow Patterns ◽  
Experimental Results ◽  
Phase Flow ◽  
Two Phase ◽  
Pressure Drops ◽  
Frictional Pressure Drop

The frictional pressure drops and two-phase flow patterns of gas-liquid two-phase flow in mini-micro pipes and at vena contract and expansion were investigated experimentally. Test liquid was water; test gas was argon. The diameter of the test mini-pipe was 0.5, 0.25 and 0.12 mm, respectively. The pressure drop data and the flow pattern were collected over 2.1 < Ug < 92.5 m/s for the superficial gas velocity and 0.03 < Ul < 10 m/s for the superficial liquid velocity. The experimental results show that the flow patterns were slug, churn, ring and annular flows; pure bubbly flow pattern was not observed in a range of the present experimental conditions. The two-phase friction multiplier data for D > 0.5 mm showed to be in good agreement with the conventional correlations. On the other hand, the two-phase friction multiplier data for D < 0.25 mm differed from the calculated values by the conventional correlations. Then, thickness of liquid film around a gas plug and size of gas core were estimated and the effect of frictional pressure drop on channel size was discussed through Knudsen Number of gas and instability on liquid-gas interface. The coefficients of sudden enlargement and sudden contraction in mini-pipes for the gas-water two-phase flow were modified from the present experimental results.

Pneumotransport of Grains Through a Pipeline

2002 ◽  
Author(s):  
Kaushal K. Shrivastava
Keyword(s):  
Mathematical Model ◽  
Pressure Drop ◽  
Experimental Results ◽  
Experimental Techniques ◽  
Horizontal Pipe ◽  
Pressure Drops ◽  
Central Topic ◽  
The Mathematical Model ◽  
Mustard Seeds

Determination of pressure drop correlation using experimental techniques has been a central topic of research in the area of pneumotransport. However, the objective of the present investigation is to apply the mathematical model (SK model) developed by the author [1,2] along with other correlations [3–5] to estimate pressure drops for conveying varieties of grains through horizontal pipe and compare the values with the experimental results of Siegel [6]. The SK model has also been utilized to calculate pressure drops for conveying mustard seeds pneumatically through horizontal, inclined and vertical pipes and compare the values with the experimental results of Rose and Barnacle [7]. It is evident from various comparisons shown in this paper that the SK model predicts the values of pressure drop accurately as compared to the experimental results in all the cases of grains transport through horizontal, inclined, and vertical pipes, whereas, other correlations do not predict accurate results consistently in all cases.

Magnetorheological Fluids Behaviour in Tension Loading Mode

2008 ◽  
Vol 47-50 ◽  
pp. 242-245 ◽  
Author(s):  
Saiful Amri Mazlan ◽  
Ahmed Issa ◽  
Abdul Ghani Olabi
Keyword(s):  
Magnetic Field ◽  
Tensile Stress ◽  
Magnetic Particles ◽  
Electrical Current ◽  
High Ratio ◽  
Solid Particles ◽  
Mr Fluid ◽  
Carrier Fluid ◽  
Mr Fluids ◽  
Water Based

In this paper, the behaviours of three types of MR fluids under quasi-static loadings in tension mode were investigated. One type of water-based and two types of hydrocarbon-based MR fluids were activated by a magnetic field generated by a coil using a constant value of DC electrical current. Experimental results in terms of stress-strain relationships showed that the MR fluids had distinct unique behaviours during the tension process. A high ratio of solid particles to carrier liquid in the MR fluid is an indication of high magnetic properties. The water-based MR fluid had a relatively large solid-to-liquid ratio. At a given applied current, a significant increase in tensile stress was obtained in this fluid type. On the other hand, the hydrocarbon-based MR fluids had relatively lower solid to liquid ratios, whereby, less increases in tensile stress were obtained. The behaviours of MR fluids were dependent on the relative movement between the solid magnetic particles and the carrier fluid. A complication occurs because, in the presence of a magnetic field, there will be a tendency of the carrier fluid to stick with the magnetic particle

Research and Development on No-Moving-Part Valves Using Enhancement

2009 ◽  
Author(s):  
Kai-Shing Yang ◽  
Young-Chang Liu ◽  
Chi-Chuan Wang ◽  
Jin-Cherng Shyu
Keyword(s):  
Reynolds Number ◽  
Pressure Drop ◽  
Research And Development ◽  
Experimental Results ◽  
Efficiency Ratio ◽  
Circular Area ◽  
Interface Friction ◽  
Pressure Drops ◽  
Micro Nozzle ◽  
Maximum Improvement

This study characterizes and analyzes the performances of micro diffusers/nozzles with six types of enhancement structures. The pressure drops across the designed micro nozzles/diffusers are found to be increased considerably when the obstacle and fin structure are added. Further, the micro nozzle/diffuser having added circular area reveals the lowest pressure drop, owing to the hydraulic diameter is increased by circular area and lower interface friction. The maximum improvement of the loss coefficient ratio is about 16% for an added 3-fin structure operated at a Reynolds number around 70. Upon this situation, the static rectification efficiency improves 4.43 times than the conventional nozzle/diffuser. Experimental results indicate the performance peaks at a Reynolds number around 70, and an appreciable decline is encountered when the Reynolds number is reduced. It is due to the efficiency ratio of conventional micro nozzle/diffuser significant increases with the Reynolds number.

Experimental and Analytical Studies on Frictional Pressure Drops of Gas-Liquid Two-Phase Flow in Mini-Micro Pipes and at Vena Contract and Expansion

2007 ◽  
Author(s):  
Hiroyasu Ohtake ◽  
Hideyasu Ohtaki ◽  
Masato Hagiwara ◽  
Yasuo Koizumi
Keyword(s):  
Pressure Drop ◽  
Two Phase Flow ◽  
Liquid Velocity ◽  
Experimental Results ◽  
Phase Flow ◽  
Two Phase ◽  
Pressure Drops ◽  
Frictional Pressure Drop ◽  
Sudden Contraction ◽  
Sudden Enlargement

The frictional pressure drops of gas-liquid two-phase flow in mini-micro pipes and at vena contract and expansion were investigated experimentally and analytically. Pressure drops of straight pipe, sudden enlargement and sudden contraction of gas-liquid two-phase flow in mini-pipes were measured. Test liquid was water at room temperature; test gas was argon. The diameter of the test mini-pipe was 0.5, 0.25 and 0.12 mm, respectively; the length was 500, 250 and 50 mm, respectively. The cross-sectional ratio of the contraction was about 1000; the ratio of the enlargement was about 0.001. The pressure drop data and the flow pattern were collected over 3.0 &lt; UG &lt; 130 m/s for the superficial gas velocity and 0.02 &lt; UL &lt; 6.0 m/s for the superficial liquid velocity. The two-phase friction multiplier data for D &gt; 0.5 mm showed to be in good agreement with the conventional correlations. On the other hand, the two-phase friction multiplier data for D &lt; 0.25 mm differed from the calculated values by the conventional correlations. Then, thickness of liquid film around a gas plug and size of gas core were estimated and the effect of frictional pressure drop on channel size was discussed through Knudsen Number of gas and instability on liquid-gas interface. Namely, the effect of mini-pipe was rarefaction effects, Kn&lt;0.1. New correlation of frictional pressure drop of gas-liquid two-phase flow is proposed for mini pipes. The coefficients of sudden enlargement and sudden contraction in mini-pipes for the gas-water two-phase flow were modified from the present experimental results. The experimental results were also examined through numerical simulation by a commercial code.

Magnetorheological Fluid Flow in Microchannels

2010 ◽  
Vol 77 (4) ◽  
Author(s):  
Joseph Whiteley ◽  
Faramarz Gordaninejad ◽  
Xiaojie Wang
Keyword(s):  
Magnetic Field ◽  
Fluid Flow ◽  
Pressure Drop ◽  
Dynamic Pressure ◽  
Magnetorheological Fluid ◽  
Fused Silica ◽  
Experimental Results ◽  
Microchannel Flow ◽  
Roughness Effects ◽  
Good Agreement

This study presents experimental results on the flow of magnetorheological grease (MRG) through microchannels. MR materials flowing through microchannels create microvalves. The flow is controlled by injecting the MRG through microchannels with controlled adjustable rates. To study the effect of different channel diameters and surface roughnesses, microchannels made of stainless steel, PEEK, and fused silica materials with nominal internal diameters ranging from 1 mm to 0.075 mm (75 μm) are tested. A magnetic field is applied perpendicular to the microchannel flow and is controlled by an input electric current. The pressure drop of the flow is measured across the length of the microchannels. The dynamic pressure drop range and surface roughness effects are also discussed. The Herschel–Bulkley model for non-Newtonian fluid flow is employed to the experimental results with good agreement. The results show a significant pressure drop for different magnetic field strengths.

scholarly journals Influence of the Drop Volume and Applied Magnetic Field on the Wetting Features of Water-based Ferrofluids

2020 ◽  
Vol 5 (9) ◽  
pp. 1110-1116
Author(s):  
Barenten Suciu
Keyword(s):  
Magnetic Field ◽  
Contact Angle ◽  
Magnetic Flux ◽  
Applied Magnetic Field ◽  
Magnetic Particles ◽  
Permanent Magnets ◽  
Field Energy ◽  
Drop Volume ◽  
Magnetic Field Energy ◽  
Water Based

In this work, the influence of the drop volume and applied magnetic field on the wetting features of water-based ferrofluids, is experimentally investigated. Firstly, water drops with volume in the range of 0.1–100 micro-liters are placed, by using micro-pipettes, on bare and coated acrylic plates, to gain reference data concerning the contact angle. Then, drops of water-based ferrofluid, with the volume ranging from 1 to 10 micro-liters, are set on bare acrylic plates, which are placed into the uniform magnetic field created, in normal direction to the plate, by using permanent magnets. Since the ferrofluid drops are elongated along the magnetic field, the contact angle increases at augmentation of the magnetic flux. Besides, when a critical magnetic flux is exceeded, ferrofluid drop loose contact with the plate and jumps towards the magnet. A heuristic equation to predict the fluctuation of the liquid surface tension versus the drop volume, and also versus the ratio of the applied magnetic field energy to the kinetic energy of the magnetic particles dispersed into the water-based ferrofluid, is suggested.

A Design of a Multiple-Level Magnetic Field Used for Driving Micro Magnetic Particles During a Dialysate Adsorption Process

2016 ◽  
Author(s):  
Junfeng Lu ◽  
Wen-qiang Lu
Keyword(s):  
Magnetic Field ◽  
Magnetic Particles ◽  
Design Method ◽  
Recovery Process ◽  
Multiple Level ◽  
Magnetic Intensity ◽  
Micro Particles ◽  
Magnetic Adsorbents ◽  
Magnetic Seeds ◽  
Dialysate Solution

Recently in our research studies, ferroferric oxide magnetic micro particles were used as magnetic seeds combining with adsorbent materials during post hemodialysis (HD) nutrition recovery process. The combined particles were designed as magnetic adsorbents to selectively take back nutritional substances from waste dialysate solution, and then, these substances can be further chemically released to blood. To allow a better adsorption performance, these particles should be trapped inside their working area. So, a gradient magnetic field was designed accordingly. Instead to use a permanent magnet which could accumulate magnetic particles, the field was produced by multiple-level magnetic solenoid coils. This paper outlined the design method for the multiple-level solenoid field. And then, the measurement results for the magnetic intensity at different axis locations inside the solenoid field were compared with the numerical computation results. The computation results also showed that, near the axis area of the multiple-level solenoid, the magnetic intensity is smoothly developed. This feature allows the easy movement of magnetic particles since an abrupt gradient tends to accumulate the particles.

Sign in / Sign up

Export Citation Format

Share Document