Study on the flow features of lead-lithium MHD splitting flows under an external magnetic field with arbitrary orientation

Yang Luo,Yiping Chen,Chang Nyung Kim 대한기계학회 2021 JOURNAL OF MECHANICAL SCIENCE AND TECHNOLOGY Vol.35 No.10

The understanding of magnetohydrodynamic phenomena associated with the flow of electrically-conducting fluid in complex ducts is important and necessary in the study of liquid-metal blankets for fusion reactor. This study numerically investigates the lead-lithium (Pb-17Li) magnetohydrodynamic (MHD) splitting flows. The effects of the splitting angle of the duct geometry, the magnetic field orientation and the partly different electrical conductivity of the structural walls on the flow characteristics are analyzed in detail. Furthermore, the combined effects of the splitting angle, the magnetic field orientation and duct electrical conductivity on the mass flow rate and pressure drop are considered with many sub-cases. The results show that the mass imbalance and the pressure drop depend on the splitting angle of the duct geometry, on the discrepancy of the electrical conductivity of the sub-channels and also on the magnetic field orientation. In a word, this study can support several approaches to improve the flow imbalance and to reduce the pressure drop in the sub-channels of the liquid-metal (LM) MHD splitting flow system.

RESEARCH ON THE CRASHWORTHINESS OF REGULAR CENTURION 2M BARRIER BASED ON THE ARBITRARY LAGRANGE-EULER METHOD

Dongwei Yuan,Yiping Luo,Yong Peng 한국자동차공학회 2019 International journal of automotive technology Vol.20 No.3

In this study, the crash-worthiness of a regular Centurion 2M barrier, which is a type of portable water-filled barrier (PWFB), is evaluated under different collision conditions. A numerical model of the regular Centurion 2M barrier, consisting of a plastic shell and water, was developed and validated. The validity of the numerical model is demonstrated by comparisons to experimental results. During the establishment of the finite element numerical model, the ALE (Arbitrary Lagrange-Euler) method was used to solve the problem of the fluid-structure interaction of the PWFB system. This model can be extended to a series of impact cases including an actual pick-up truck. Impact cases set six collision conditions according to different collision speeds and angles. The dynamic response of the collision between the pick-up truck and the PWFB process was investigated. From the analysis, we find that the greater the collision angle is, the greater the impact is on the collision result. According to the actual accident collision angle, setting the collision angle above 50° is satisfactory in most situations. In addition, a regular Centurion 2M barrier is just suitable for use on roads when the speed of vehicles is 20 km/h or less.

Research on characterization method and influencing factors of sedimentation stability of magnetorheological fluid

Yuqing Li,YiPing Luo,Ying Wang,Jiao Luo,Yameng Chen 한국유변학회 2021 Korea-Australia rheology journal Vol.33 No.4

The sedimentation stability of Magnetorheological fluid (MRF) is one of the research hotspots in the academic field of magnetorheological science. Excellent sedimentation stability is of great significance for the preservation and application of MRF. Given many traditional methods of characterization of sedimentation stability, this paper proposes a new method to characterize the sedimentation stability of MRF based on the change of shear yield stress during the sedimentation process of MRF. Then, the key components of the selfmade MRF shear yield stress test device were introduced in detail, and three different surfactants containing dodecyl benzoate, polyethylene glycol and oleic acid were prepared. And then used the device to test their effects on the sedimentation stability of MRF. The results showed that oleic acid has the best effect on improving the sedimentation stability. Finally, the change law of shear yield stress of MRF in the next 90 days was predicted successfully by fitting experimental data based on the least square method. By comparing the test value and fitting value of 60-75 days, the error of the best fitting result were within 3%, this showed the reliability of the predicted results.

Research on Temperature Field of a New Type of Magnetorheological Fluid Dynamometer with Cooling System

Lei Wang,YiPing Luo,Hui Ying Liang,Meng Ji 한국자기학회 2019 Journal of Magnetics Vol.24 No.4

In order to study the temperature characteristics of magnetorheological fluid dynamometer, the torque model and working principle of magnetorheological fluid dynamometer were analyzed, the temperature experiment of magnetorheological fluid dynamometer was conducted, and the experimental data were analyzed and processed in this paper. The fitting curves between the speed of magnetorheological fluid dynamometer and the experimental temperature, the speed and the torque, the current and the torque as well as the current and the temperature were obtained. Then, the temperature field of magnetorheological fluid was simulated by FLUENT based on the experimental data. The temperature field nephograms and temperature values of test points under different working conditions were obtained. Comparing the experimental values with the simulation values, the relative error was less than 7.8 %, which was within a reasonable range. Finally, from the aspect of temperature reduction, the simulation model was optimized. Based on the principle of heat convection, the simulation model was reconstructed. The maximum temperature drop was 10℃.

Numerical Simulation of Magnetorheological Liquid Sedimentation Character

Jun Qiu,YiPing Luo,Jiao Luo,Ying Wang,Hongyi Wang 한국자기학회 2020 Journal of Magnetics Vol.25 No.3

In this paper, numerical simulation is used to simulate the sedimentation process of magnetorheological fluid (MRF), and the sedimentation time of MR fluid is predicted by this method. Firstly, based on the existing literature simulation method and its improvement, a numerical simulation method is proposed to simulate the MR fluid sedimentation process. Finally, a variety of MR fluid samples are prepared to detect the accuracy of the simulation results of the constructed numerical simulation method. It can be proved by comparing the measured sedimentation time with the simulated sedimentation time, and the method constructed in this paper can predict the sedimentation time of the more complicated MR fluid well, which has good practicability.

Identification of putative ingestion‑related olfactory receptor genes in the Chinese mitten crab (Eriocheir japonica sinensis)

Chenchen Shen,Dan Tang,Yiping Zhang,Lv Wu,Yaqi Luo,Boping Tang,Zhengfei Wang 한국유전학회 2021 Genes & Genomics Vol.43 No.5

Background Olfaction plays a central role in mating, spawning, obtaining food and escaping predators, which is essential for survival and reproduction of animals. The nature of the olfactory perception in crabs, which is a major group of crustaceans, has remained elusive. Objective This project aims to explore the molecular mechanism of olfaction in crabs and further improve our understanding of olfactory perception in crustaceans. Methods The olfactory receptors and ingestion-related gene expression in Eriocheir japonica sinensis were studied by transcriptomic techniques. The de novo assembly, annotation and functional evaluation were performed with bioinformatics tools. Results A series of chemosensory receptors associated with olfaction were identifed including 33 EsIRs, 24 EsIGluRs, 58 EsVIGluRs, 1 EsOR and 1 EsGC-D. We found IRs were key odorant receptors demonstrating a specifc species evolutionary trend in crustaceans. Furthermore, we identifed ORs in E. j. sinensis and Litopenaeus vannamei. The incomplete EsOR and LvOR1 structures implied that ORs exist in crustaceans, and may have been degenerated or even lost in the olfactory evolutionary process. In addition, comparative transcriptome analysises demonstrated two possible olfactory transduction pathways of E. j. sinensis: the cGMP-mediated olfactory pathway related to vegetable odor molecules and the cAMP-mediated olfactory pathway related to meat odor molecules. The above results were consistent with its omnivorous ingestion of E. j. sinensis. Conclusions Our study revealed the unique olfactory molecular mechanism of omnivorous crabs and provided valuable information for further functional research on the chemoreception mechanisms in crustaceans.