Structural Optimization of Reciprocating Seal with Magnetic Fluid Based on Orthogonal Test Design

Xiaolong Yang,Gang Liu,You Li,Shanghan Gao 한국자기학회 2021 Journal of Magnetics Vol.26 No.2

Experimental Study on Divergent Magnetic Fluid Seal with Small Clearance and Double Magnetic Source

Xiaolong Yang,Chenguang Yang,Gang Liu 한국자기학회 2022 Journal of Magnetics Vol.27 No.1

In order to solve the problem of poor sealing performance of rotating machinery under the condition of small clearance, a new type of divergent magnetic fluid seal device with small clearance and double magnetic source is designed in this paper. The effect of magnetic fluid injection, tooth number and sealing clearance on the sealing pressure resistance of dual magnetic source divergence were studied and compared with the experimental value of ordinary magnetic fluid seal. The experiment results show that the pressure resistance ability of divergent magnetic fluid seal is at least 3 times that of ordinary magnetic fluid seal, which verifies the correctness of divergent magnetic seal with small clearance and double magnetic source pressure resistance theory, and has important theoretical guiding significance for solving the problem of poor magnetic fluid seal performance under small clearance.

Effect of Particle Size and Dispersion on Dielectric Properties in ZnO/Epoxy Resin Composites

Yang, Wenhu,Yi, Ran,Yang, Xu,Xu, Man,Hui, Sisi,Cao, Xiaolong The Korean Institute of Electrical and Electronic 2012 Transactions on Electrical and Electronic Material Vol.13 No.3

In this paper, ZnO-Epoxy nanocomposites (NEP) were prepared and epoxy composites that contain 5 wt% micro ZnO (MEP) and deliberately not well dispersed nano ZnO (NDNEP) were also prepared for purpose of comparison. The effects of the particle size and dispersion of ZnO on dielectric properties of epoxy resin were chiefly studied. Test results showed that: at a loading of 5 wt%, the three epoxy composites seem to have no significant difference on resistivity compared to epoxy resin; Dielectric constants of all the epoxy composites are also basically the same but they are bigger compared to that of the pure epoxy resin (unfilled); Dielectric dissipation factors ($tan{\delta}$) of NDNEP is greater than that of NEP and MEP. NEP has the minimum dielectric loss factor, whereas dielectric loss factors of the three epoxy composites are larger than that of the pure epoxy resin. The decreasing order of electrical breakdown strength for the three epoxy composites and for the pure epoxy resin is as follows: NEP>MEP>NDNEP>EP. Finally, in order to explain the experimental results the aggregation interface phase was proposed. Furthermore, addition of well dispersed nano filler has proved to have a positive effect on the improvement of the dielectric properties of epoxy resin.

Experimental Research on Self-repairing of Diverging Stepped Magnetic Fluid Seals with Single Magnetic Source

Xiaolong Yang,Yuting Liu,Ruibo Zhang,Shanghan Gao 한국자기학회 2021 Journal of Magnetics Vol.26 No.4

To improve the self-repairing capability of common magnetic fluid seal structures after rupture due to excessive differential pressure in small clearance conditions and to verify the superiority of diverging stepped magnetic fluid seals, a diverging stepped magnetic fluid seal device with single magnetic source was tested. The effect of injection volume, clearance and numbers of teeth on the self-repairing performance of a diverging stepped magnetic fluid seals was investigated experimentally and compared with a common magnetic fluid seal. The experimental results indicate that the self-repairing performance of one stepped magnetic fluid seal device is better. The repair rate of a diverging stepped magnetic fluid seal structure decreases first and then increases with the increase of injection volume, and a minimum value is reached near the saturation value. The smaller the sealing gap and the fewer the number of bore teeth, the higher the repair rate of this structure.

Investigation of Thermal Response Model for Solar Irradiance Absolute Radiometer

Xiaolong Yi,Wei Fang,Yang Luo,Xin Ye,Dongjun Yang,Yupeng Wang 보안공학연구지원센터 2016 International Journal of Multimedia and Ubiquitous Vol.11 No.6

Design and Numerical Study of Hybrid Magnetic Source Disc-type Magnetorheological Valve

Xiaolong Yang,Yan Li,Youming Zhou,Shiying Zhou,Jiehong Zhu 한국자기학회 2023 Journal of Magnetics Vol.28 No.2

Magnetorheological valves are important components in hydraulic systems that provide precise position control. At present, the low-pressure drop performance of magnetorheological valves is the main problem limiting their application. To improve the pressure drop performance of magnetorheological valves, a hybrid magnetic source disc magnetorheological valve is proposed. The magnetic pressure drop model and viscous pressure drop model of the hybrid magnet source disc type magnetorheological valve based on the Bingham model are Derived. Magnetic field distributions in the damping channel of the hybrid magnet source disc type magnetorheological valve are obtained by using ANSYS finite element analysis software. The mathematical model of the relationship between pressure drop and magnetic induction intensity was established using Matlab software, and the effects of parameters such as effective current, axial damping gap, radial damping gap, and coil width on the pressure drop performance of disc-type magnetorheological valves with hybrid magnetic sources were numerically analyzed. The results show that the pressure drop of the disc magnetorheological valve with a hybrid magnetic source can reach 10.9935 MPa at the current I=3A, axial damping gap ga=1 mm, and radial damping gap gr=1.5 mm. Compared with the conventional disc magnetorheological valve, the pressure drop performance of the hybrid magnetic source disc magnetorheological valve is improved by 28 %, which provides ideas on how to improve the pressure drop performance of the magnetorheological valve.

Magnetic Circuit Design and Numerical Study of Diverging Stepped Magnetofluid Seal with Small Clearance

Xiaolong Yang,Ruibo Zhang,Guohong Wang 한국자기학회 2020 Journal of Magnetics Vol.25 No.2

In order to obtain the maximum magnetic energy product in the sealing clearance of magnetofluid seal and improve its critical pressure, a diverging stepped magnetofluid seal with small clearance was designed based on the magnetic circuit design theory and the magnetofluid seal theory. Magnetic distribution and its theoretical critical pressure were calculated by the finite element method, which could prove the reliability of design method in the magnetic circuit. The paper studies the effects of axial clearance, radial clearance and pole tooth number on the pressure capabilities of diverging stepped magnetofluid seal in specific values, which were analyzed and compared in details. The results show that the magnetic flux leakage at the junction of the pole piece and the permanent magnet in the diverging stepped magnetofluid seal leads the theoretical critical pressure calculated by the magnetic circuit method to be lower than that calculated by the finite element method. Moreover, when the pole tooth number in the axial clearance is not less than the pole tooth number in the radial clearance, and the width of axial clearance is smaller than the height of radial clearance, the critical pressure of diverging stepped magnetofluid seal is better than that of the ordinary magnetofluid seal.

Across-fault distributions of radon concentrations in soil gas for different tectonic environments

Xiaolong Sun,Pengtao Yang,Yang Xiang,Xueyun Si,Dongying Liu 한국지질과학협의회 2018 Geosciences Journal Vol.22 No.2

The radon concentration in soil gas at the crustal surface is closely related to the development of local fractures. Therefore, the spatial variation in soil-gas radon concentrations across faults differs between fault zones located in different tectonic environments. This study investigates the Beiluntai thrust fault and the Haiyuan strike-slip fault in west China, which are assumed to be typical examples of the different types of faults. Radon concentrations in soil gas were measured at various locations around these faults, and the spatial variation in these concentrations was characterized along fault-perpendicular profiles. For normal fault, our results indicate that concentrations are usually highest at the fault, and decrease gradually away from the fault in either direction. For thrust, however, concentrations increase in the hanging wall approaching the fault, but decrease sharply at the fault. For strike-slip fault with extension across the fault, soil-gas radon concentrations are relatively high at the fault, and decrease gradually with distance from the fault. For strike-slip fault with contraction across the fault, soil-gas radon concentrations are relatively low at the fault, and increase gradually with distance from the fault.

Effect of Particle Size and Dispersion on Dielectric Properties in ZnO/Epoxy Resin Composites

Wenhu Yang,Ran Yi,Xu Yang,Man Xu,Sisi Hui,Xiaolong Cao 한국전기전자재료학회 2012 Transactions on Electrical and Electronic Material Vol.13 No.3

In this paper, ZnO-Epoxy nanocomposites (NEP) were prepared and epoxy composites that contain 5 wt% micro ZnO (MEP) and deliberately not well dispersed nano ZnO (NDNEP) were also prepared for purpose of comparison. The effects of the particle size and dispersion of ZnO on dielectric properties of epoxy resin were chiefly studied. Test results showed that: at a loading of 5 wt%, the three epoxy composites seem to have no significant difference on resistivity compared to epoxy resin; Dielectric constants of all the epoxy composites are also basically the same but they are bigger compared to that of the pure epoxy resin (unfilled); Dielectric dissipation factors (tanδ) of NDNEP is greater than that of NEP and MEP. NEP has the minimum dielectric loss factor, whereas dielectric loss factors of the three epoxy composites are larger than that of the pure epoxy resin. The decreasing order of electrical breakdown strength for the three epoxy composites and for the pure epoxy resin is as follows: NEP>MEP>NDNEP>EP. Finally,in order to explain the experimental results the aggregation interface phase was proposed. Furthermore, addition of well dispersed nano filler has proved to have a positive effect on the improvement of the dielectric properties of epoxy resin.

Research on the Performance of Magnetorheological Semi-Active Suspension with Stepped By-Pass Valve based on Fuzzy PID Control

Chenguang Yang,Xiaolong Yang,Youming Zhou 한국자기학회 2023 Journal of Magnetics Vol.28 No.3

At present, most of the seat suspensions of heavy-duty trucks use passive suspension and active suspension. The passive suspension has gradually failed to meet people's needs in terms of vibration reduction performance, and the active suspension will consume too much energy. In this paper, a stepped by-pass valve magnetorheological semi-active suspension based on fuzzy PID control is proposed. The Simulink is used to simulate the system. In the case of sinusoidal excitation, the results show that this semi-active suspension reduces the vertical acceleration by 44.36%, the dynamic deflection of the suspension by 29.63% and the dynamic deformation of the tire by 43.78% compared with the passive suspension. Under the condition of C-level road surface input, the vertical acceleration of the suspension is reduced by 35.14%, the dynamic deflection of the suspension is reduced by 31.93%, and the dynamic deformation of the tire is reduced by 27.65%.