Study on Magnetic Fluid Static Seal of Large Gap

2012 ◽  
Vol 512-515 ◽  
pp. 1448-1454 ◽  
Author(s):  
De Cai Li ◽  
Hai Na Zhang ◽  
Zhi Li Zhang
Keyword(s):  
Magnetic Field ◽  
Theoretical Analysis ◽  
Saturation Magnetization ◽  
Magnetic Fluid ◽  
Large Diameter ◽  
Burst Pressure ◽  
The Past ◽  
Set Up ◽  
Experimental Rig ◽  
Theoretical Results

Researchers have been studying the magnetic fluid seal of small gap in the past. In order to meet the static seal requirements of large gap in aviation, aerospace, metallurgy, and so on. We set up the experimental rig of magnetic fluid static seal and designed the static seal of magnetic fluid. In the experimental rig, we studied the static seal of magnetic fluid and obtained the relationships among the burst pressure and the amount of injection of magnetic fluid, seal gap, temperature and magnetization in the experimental rig. In theory, we calculated the distribution of magnetic field under the seal gap and reasoned sustained pressure and temperature and calculated the burst pressure in different gaps and different saturation magnetization. We analyzed the experimental and theoretical results in detail. The theoretical analysis and tests indicated that magnetic fluid seal of large gap and large diameter can sustain a definite pressure and meet the requirements of practical problems.

Structure Design of Magnetic Fluid Static Seal at Large Diameter Flange

2012 ◽  
Vol 512-515 ◽  
pp. 1455-1458 ◽  
Author(s):  
Xin Zhi He ◽  
De Cai Li ◽  
Hai Na Zhang ◽  
Zhi Li Zhang
Keyword(s):  
Magnetic Field ◽  
Magnetic Fluid ◽  
Large Diameter ◽  
Aerospace Industry ◽  
Structure Design ◽  
Test Rig ◽  
Military Industry ◽  
Set Up ◽  
The Relationship ◽  
The Magnetic Field

In order to meet the requirements of the static seal at large diameter in chemical industry, aerospace industry and military industry, we designed a magnetic fluid static seal at large diameter flange and set up a test rig. We studied the effect of magnetic fluid static seal on the test rig. Finally, we obtained the relationship between the anti-pressure capacity and the number of the seal stages. We also calculated the distribution of the magnetic field in the seal gap and the anti-pressure capacity in theory. The theoretical analysis and the experiment result indicate that the design of the magnetic fluid static seal at large diameter flange is feasible and can be used to meet the practical problems.

scholarly journals Optimising the AR Engraved Structure on Light-Guide Facets for a Wide Range of Wavelengths

Optics ◽  
2020 ◽  
Vol 2 (1) ◽  
pp. 25-42
Author(s):  
Ioseph Gurwich ◽  
Yakov Greenberg ◽  
Kobi Harush ◽  
Yarden Tzabari
Keyword(s):  
Theoretical Analysis ◽  
Light Guide ◽  
Spectral Band ◽  
Angular Range ◽  
The Past ◽  
Input And Output ◽  
Wide Range ◽  
The Given ◽  
Theoretical Results ◽  
Shape And Size

The present study is aimed at designing anti-reflective (AR) engraving on the input–output surfaces of a rectangular light-guide. We estimate AR efficiency, by the transmittance level in the angular range, determined by the light-guide. Using nano-engraving, we achieve a uniform high transmission over a wide range of wavelengths. In the past, we used smoothed conical pins or indentations on the faces of light-guide crystal as the engraved structure. Here, we widen the class of pins under consideration, following the physical model developed in the previous paper. We analyze the smoothed pyramidal pins with different base shapes. The possible effect of randomization of the pins parameters is also examined. The results obtained demonstrate optimized engraved structure with parameters depending on the required spectral range and facet format. The predicted level of transmittance is close to 99%, and its flatness (estimated by the standard deviation) in the required wavelengths range is 0.2%. The theoretical analysis and numerical calculations indicate that the obtained results demonstrate the best transmission (reflection) we can expect for a facet with the given shape and size for the required spectral band. The approach is equally useful for any other form and of the facet. We also discuss a simple way of comparing experimental and theoretical results for a light-guide with the designed input and output features. In this study, as well as in our previous work, we restrict ourselves to rectangular facets. We also consider the limitations on maximal transmission produced by the size and shape of the light-guide facets. The theoretical analysis is performed for an infinite structure and serves as an upper bound on the transmittance for smaller-size apertures.

scholarly journals Mechanics of magnetic fluid active element in strong magnetic field

2018 ◽  
Vol 185 ◽  
pp. 09005
Author(s):  
V.M. Polunin ◽  
P.A. Ryapolov ◽  
E.V. Sheldeshova
Keyword(s):  
Magnetic Field ◽  
Experimental Data ◽  
Saturation Magnetization ◽  
Strong Magnetic Field ◽  
Magnetic Fluid ◽  
Active Element ◽  
Magnetic Levitation ◽  
Static Displacement ◽  
Temporal Dependence ◽  
Good Agreement

Measurements and theoretical analysis of the processes of static displacement and oscillations of the magnetic fluid column confined by magnetic levitation in a strong magnetic field in a horizontally placed tube are carried out. The calculations of the saturation magnetization, made on the basis of the obtained results of the displacement and the oscillation frequency for the sample of the magnetic fluid under study, are in good agreement with the experimental data. The described technique is of interest when studying saturation magnetization, magnetophoresis, aggregation of nanoparticles and their temporal dependence in magnetic colloids.

Experimental Study on the Second-Order Buoyancy of Magnetic Fluid

2012 ◽  
Vol 512-515 ◽  
pp. 1464-1469 ◽  
Author(s):  
Xin Zhi He ◽  
De Cai Li ◽  
Wen Ming Yang ◽  
Hai Na Zhang
Keyword(s):  
Magnetic Field ◽  
Experimental Study ◽  
Numerical Calculation ◽  
Permanent Magnet ◽  
Saturation Magnetization ◽  
Experimental Method ◽  
Magnetic Fluid ◽  
Second Order

The buoyancy principle of magnetic fluid is one of the most attractive effects of magnetic fluid statics. But it is too difficult to calculate the buoyancy directly due to the complexity of magnetic field. Moreover, numerical calculation employs too many assumptions. So in this paper the experimental method is adopted to measure the second-order buoyancy received by permanent magnet immersed in magnetic fluid, which depends on the distance between the magnet and the wall of vessel. The influence of the diameter of cylindrical vessels, the size of magnets and the saturation magnetization of magnetic fluid on the buoyancy is also analyzed qualitatively.

scholarly journals Outlook for Ground-Based and Space Observations

1983 ◽  
Vol 102 ◽  
pp. 505-507
Author(s):  
G.S. Vaiana
Keyword(s):  
Magnetic Field ◽  
Experimental Science ◽  
Ancillary Study ◽  
The Past ◽  
Solar Type ◽  
New Space ◽  
To Come ◽  
New Research ◽  
Theoretical Results ◽  
Space Observations

The presentations given at this Symposium have made clear that we are witnessing an exciting period in the study of solar activity, and in the ancillary study of magnetic field dynamics in solar-type stars: the new space observations obtained within the past four years, together with the renaissance in ground-based observations, have occasioned a burgeoning in our phenomenological understanding of stellar activity in its manifold facets, and have encouraged a substantially greater interest in the problem of magnetically-coupled activity in stars by the theoreticians. This excitement must not distract us from the realization that in this branch of our science, much of the impetus towards new research has come, and very likely will continue to come, from observations; with this fact in mind, I would like to address the possible evolution of our experimental science in response to the new observational and theoretical results.

Axial Magnetic Field Distribution Simulation and Optimization in Rotating Magnetron Sputtering System

2014 ◽  
Vol 697 ◽  
pp. 382-387
Author(s):  
Ruo Fan Zhang ◽  
Ren Cheng Wang ◽  
Jia Cheng ◽  
Yi Jia Lu
Keyword(s):  
Magnetic Field ◽  
Magnetron Sputtering ◽  
Field Distribution ◽  
Axial Magnetic Field ◽  
Magnetic Field Distribution ◽  
Simulation And Optimization ◽  
Electromagnetic Coils ◽  
Set Up ◽  
Theoretical Results ◽  
Sputtering System

The primary goal of this study is to optimize the dynamic axial magnetic field distribution in magnetron sputtering system, guiding the target ions to project directly to the substrate. A group of electromagnetic coils were set up to generate an auxiliary axial magnetic field. The configuration of axial magnetic field in different electrifying modes on coils were simulated using numerical integration. Based on the general theoretical results, this paper proposed an optimization of coil arrangement and electrifying modes for a C-shape direct current(DC) magnetron. A 3D model of the coils was set up and the finite element analysis results verified the accuracy of theoretical results. Consequently, this study proposed an arrangement and electrified scheme of electromagnetic coils to provide a dynamic auxiliary axial magnetic field, which could match with the shape and movement of the primary magnetron.

scholarly journals Optimizing the AR Engraved Structure on Light-Guide Facets for a Wide Range of Wavelengths

2020 ◽  
Author(s):  
Ioseph Gurwich ◽  
Yakov Greenberg ◽  
Kobi Harush ◽  
Yarden Tzabari
Keyword(s):  
Theoretical Analysis ◽  
Light Guide ◽  
Spectral Band ◽  
Angular Range ◽  
The Past ◽  
Input And Output ◽  
Wide Range ◽  
The Given ◽  
Theoretical Results ◽  
Shape And Size

The present study is aimed at designing anti-reflective (AR) engraving on the Input-Output surfaces of a rectangular light-guide. We estimate AR efficiency, by the transmittance level in the angular range, determined by the light-guide. Using nano-engraving, we achieve a uniform high transmission over a wide range of wavelengths. In the past, we used smoothed conical pins or indentations on the faces of light-guide crystal as the engraved structure. Here, we widen the class of pins under consideration, following the physical model developed in the previous paper. We analyze the smoothed pyramidal pins with different base shapes. The possible effect of randomization of the pins parameters is also examined. The results obtained demonstrate optimized engraved structure with parameters depending on the required spectral range and facet format. The predicted level of transmittance is close to 99\%, and its flatness (estimated by the standard deviation) in the required wavelength range is 0.2\%. The theoretical analysis and numerical calculations indicate that the obtained results demonstrate the best transmission (reflection) we can expect for a facet with the given shape and size for the required spectral band. The approach is equally useful for any other form and of the facet. We also discuss a simple way of comparing experimental and theoretical results for a light-guide with the designed input and output features. In this study, as well as in our previous work, we restrict ourselves to rectangular facets. We also consider the limitations on maximal transmission produced by the size and shape of the light-guide facets. The theoretical analysis is performed for an infinite structure and serves as an upper bound on the transmittance for smaller-size apertures.

Open Localization in Micro LeadFrame Package Using Space Domain Reflectometry

2013 ◽  
Author(s):  
J. Gaudestad ◽  
V. Talanov ◽  
A. Orozco ◽  
M. Marchetti
Keyword(s):  
Magnetic Field ◽  
Radio Frequency ◽  
Standing Wave ◽  
High Resistance ◽  
Space Domain ◽  
The Past ◽  
Open Defects ◽  
Rf Electronics ◽  
Rf Signal ◽  
The Magnetic Field

Abstract In the past couple years, Space Domain Reflectometry (SDR) has become a mainstream method to locate open defects among the major semiconductor manufacturers. SDR injects a radio frequency (RF) signal into the open trace creating a standing wave with a node at the open location. The magnetic field generated by the standing wave is imaged with a SQUID sensor using RF electronics. In this paper, we show that SDR can be used to non-destructively locate high resistance failures in Micro LeadFrame Packages (MLP).

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