An Analytic Expression of Inductance Gradient for Rail-Type Electromagnetic Launcher

Nie, Jianxin; Han, Jingjing; Jiao, Qingze; Li, Jun; Qin, Jianfeng

doi:10.1109/tps.2010.2100048

Cited by 7 publications

(5 citation statements)

References 4 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…For the magnetic flux density calculation at the load position, this study compares the proposed method with the surface current method [ 30 ] and the mean rail method [ 19 ] used in the previous literature. The surface current method simplifies the rail model based on the direction of the current flow, as shown in Figure 17 a.…”

Section: Resultsmentioning

confidence: 99%

Simulation and Experimental Verification of Magnetic Field Diffusion at the Launch Load during Electromagnetic Launch

Yang,

Yin,

et al. 2023

Sensors

View full text Add to dashboard Cite

The unique magnetic field environment during electromagnetic launch imposes higher requirements on the design and protection of the internal electronic system within the launch load. This low-frequency, Tesla-level extreme magnetic field environment is fundamentally distinct from the Earth’s geomagnetic field. The excessive change rate of magnetic flux can readily induce voltage within the circuit, thus disrupting the normal operation of intelligent microchips. Existing simulation methods primarily focus on the physical environments of rails and armatures, making it challenging to precisely compute the magnetic field environment at the load’s location. In this paper, we propose a computational rail model based on the magneto–mechanical coupling model of a railgun. This model accounts for the dynamic current distribution during the launch process and simulates the magnetic flux density distribution at the load location. To validate the model’s accuracy, three-axis magnetic sensors were placed in front of the armature, and the dynamic magnetic field distribution during the launch process was obtained using the projectile-borne-storage testing method. The results indicate that compared to the previous literature methods, the approach proposed in this paper achieves higher accuracy and is closer to experimental results, providing valuable support for the design and optimization of the launch load.

show abstract

Section: Resultsmentioning

confidence: 99%

Simulation and Experimental Verification of Magnetic Field Diffusion at the Launch Load during Electromagnetic Launch

Yang,

Yin,

et al. 2023

Sensors

View full text Add to dashboard Cite

show abstract

“…It is assumed that the rail current is only distributed on each surface, and the skin depth 𝛿 is evenly distributed. The current distributions on the upper and lower surfaces of the rail and armature are the same, while the current distribution coefficients on the inner and outer surfaces are 𝑓 and 𝑓 , respectively, where 𝑓 > 𝑓 , and 𝑓 + 𝑓 = 2 [21]. The current of rail surface S1 is:…”

Section: Calculation Model Of Magnetic Induction For the Armature And...mentioning

confidence: 99%

The Influence of projectile shielding on the internal magnetic field during an electromagnetic launch

Yang¹,

Liu²,

Li³

et al. 2022

J. vibroeng.

View full text Add to dashboard Cite

Compared with a conventional propulsion system, an electromagnetic railgun is characterized by an in-bore pulsed high magnetic field. However, the dynamic distribution of the magnetic field in the projectile has rarely been experimentally studied. To this end, this paper discusses the possibility of utilizing magnetic field environment information. An equivalent model of an electromagnetic railgun is established by using the finite element method. Based on the magnetic diffusion equation and the Biot-Savart law, the in-bore magnetic induction is determined. The velocity skin effect and projectile shielding are considered in the model. Furthermore, the magnetic measurement method is presented to validate a simulation result. The results obtained from the simulation and experiment show that package shielding affects the pulse width and amplitude of the internal value. The peak magnetic induction of low carbon steel and copper is reduced by 33.6 %, and the pulse width lags by 2.7 ms. Moreover, projectile shielding has a substantial influence on the timing accuracy during launch, and the time error reaches approximately 18 %. Therefore, the in-bore magnetic field is a practical signal for the control module since it considers the influence of different projectile shields.

show abstract

“…they provide some initial understanding of the field distribution of EMRL. Based on the Biot-Savat law and considering the skin effect of current distribution, Nie et al derived the spatial magnetic field distribution of rectangular aperture [12]. Through parametric simulations, Keshtakar calculated the current density and magnetic flux density distribution of two-dimensional rail sections of different sizes [13].…”

Section: Introductionmentioning

confidence: 99%

An Adaptive Mesh Global Modeling Method for Solving Non-ideal Sliding Electrical Contact Problems

Sun,

Cheng,

Xiong

et al. 2024

PIER M

View full text Add to dashboard Cite

The armature and rail sizes of electromagnetic rail launcher vary greatly, and the refined 3D finite element computation occupies a large amount of physical memory. In order to enhance the economy of dynamic computation, this paper proposes an adaptive hexahedral mesh method based on mesh expansion, compression, and translation. In addition, split nodes are used on both sides of the contact surface, and interface conditions and frictional heat sources are constrained through point penalty function method to solve non-ideal sliding electrical contact problems. Comparative calculations with the same type of software and the same model are carried out, and the results calculated in this paper are consistent with the relevant results of MEAP3D. This paper also compares the EMRL calculation results of adaptive mesh model and constant mesh model to verify the reliability of the method. In addition, the C-type EMRLs are compared and analyzed. The results show that due to the influence of velocity skin effect, the dynamic inductance gradient of the rail gradually increases over time and is greater than the static value. The maximum difference between the two is 5.65% of the dynamic inductance gradient. The steel shell generates eddy currents, causing a decrease in armature velocity of 4.7 m/s under the small caliber launcher. The maximum eddy current density waveform of the shell exhibits two peaks. In the frictionless heat, the temperature of the armature is underestimated, and under the action of frictional heat, the trailing edge of the armature is ablated and melted.

show abstract

An Analytic Expression of Inductance Gradient for Rail-Type Electromagnetic Launcher

Cited by 7 publications

References 4 publications

Simulation and Experimental Verification of Magnetic Field Diffusion at the Launch Load during Electromagnetic Launch

Simulation and Experimental Verification of Magnetic Field Diffusion at the Launch Load during Electromagnetic Launch

The Influence of projectile shielding on the internal magnetic field during an electromagnetic launch

An Adaptive Mesh Global Modeling Method for Solving Non-ideal Sliding Electrical Contact Problems

Contact Info

Product

Resources

About