Thickness Of Armature Research Articles

Armature Structure Optimization of Annular Multipole Solenoid Valves Based on Electromagnetic Force Distribution

To improve the dynamic response speed of high-speed solenoid valves in electric fuel injection systems of marine diesel engines, a numerical simulation model of the solenoid valve is described in this paper. The accuracy of the simulation model was verified on the test bed of the solenoid valve. The effect of the punch position and the size of the dynamic response of the solenoid valve were investigated by using the distribution law of the electromagnetic force in the armature. The results of the test showed that armature drilling in the inter-yoke zone can optimize the solenoid closing response time, but it has little impact on the solenoid opening response time. From this rule, two groove schemes were further designed. Through comparison and calculation, it can be concluded that the fan groove scheme is better than the trapezoidal groove scheme, and that the opening and closing response times of the solenoid valve should be targeted in order to multi-target optimize the fan groove geometric parameters and the armature thickness. The results show that after optimization, the weight of the motion part is reduced by 21.6%, the opening response time of the solenoid valve is reduced by 11.1%, and the closing response time is reduced by 30.0%. While reducing the oil film damping of the armature motion, the overall dynamic response characteristics of the solenoid valve are improved.

Armature Structure Research of an Electromagnetic Reconnection Launcher

The armature of the electromagnetic reconnection launcher (EMRCL) plays a key role in accelerating large-mass loads, which have attracted extensive attention in past years. In this article, the effects of the armature thickness, length, and width on the performance of the EMRCL are analyzed for designing a high-strength and high-efficiency armature. First, according to the deformation and Von Mises’ stress distribution of the armature in the electromagnetic structure field, the armature thickness should be six times the skin depth. Then, the orthogonal experiment method results demonstrate that the armature speed tends to a saturated value with increasing length and width. Finally, a three-stage EMRCL platform with a load of 10 kg was constructed to verify the accuracy of the simulation results of three armatures with different lengths and widths. The experimental results show that the speed of 80 <inline-formula xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"> <tex-math notation="LaTeX">$\times120$ </tex-math></inline-formula> mm <sup xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">2</sup> armature can reach 11.26 m/s, which is a significant increase of 23 times than the 40 <inline-formula xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"> <tex-math notation="LaTeX">$\times120$ </tex-math></inline-formula> mm <sup xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">2</sup> armature and is consistent with the simulation results. It indicates that the optimal armature length is 1.2 times the coil length, and the optimal width is 1.3 times the coil width. This research provides a valuable reference for the armature design of EMRCL.

Study on Multi-Segment Asynchronous Induction Coilgun Launcher

This article studies a multi-segment capacitively driven asynchronous induction coil launcher. First, a segment with six-stage asynchronous induction coil launcher is studied. Based on the results of the single-segment induction coil launcher and the orthogonal design method, a six-factor and five-level orthogonal table is established. The factors are, namely, trigger position, armature thickness, initial capacitance voltage, inner radius of coil, turns of coil, and coil axial length. The results of the orthogonal test show that the influencing factors from large to small are coil turns, coil axial length, initial capacitance voltage, coil radius, trigger position, and armature thickness. Based on the above results, a two-segment asynchronous induction coil launcher is designed. The coil parameters of the second section are the same as those of the first section, and the number of coils is twice that of the first section. By studying the trigger position, capacitance, and voltage combination of the second stage, the optimal trigger position is 163 mm, capacitance value is 1125 μF, and capacitance voltage is 4 kV. On account of the above research results, a four-segment induction coil launcher with two armatures is proposed. The parameters of the first and third segments are the same, and the parameters of the second and fourth segments are the same. The first and second segments drive armature 1, and the third and fourth segments drive armature 2. In the case of cross ignition, the standard deviation of armature force is 18.62 kN, while the standard deviation of armature force for sequential ignition is 25 kN. Through cross ignition, higher armature muzzle velocity and smaller acceleration jitter can be obtained.

Key design parameters and optimum method of medium- and high-velocity synchronous induction coilgun based on orthogonal experimental design**Project supported by the National Natural Science Foundation of China (Grant No. 5140130).

The energy conversion efficiency of a multistage synchronous induction coilgun (MSSICG) has become one of the key factors that restricts its industrialization. To improve the launch efficiency of medium- and high-velocity MSSICG, we propose an optimization design scheme combining orthogonal experimental design (OED) and self-consistent design method in this paper. The OED is introduced to reduce the number of iterations and improve the identification accuracy and efficiency. A self-consistent design model is established to overcome a defect that the parameters that need to be optimized will multiply as the number of coil stages increases. The influence of six factors (radial thickness of armature, axial length of armature, axial length of coil, capacitance, wire diameter, and slip speed) on the launch efficiency are then evaluated by range analysis. This work presents a valuable reference for optimizing medium- and high-velocity MSSICG.

Some Key Parameters of Monolithic C-Type Armature in Rectangular Caliber Railgun

Monolithic C-type armature is one of the most important armatures in electromagnetic railgun. Some key parameters of monolithic C-type armature in rectangular caliber railgun system—width of armature X, height of armature Y, thickness of armature’s throat $d_{0}$ , length of armature’s tail $d_{1}$ , thickness of trailing edge of armature’s tail $d_{2}$ , and angle of armature’s tail $\theta $ —are studied in this paper. By introducing current carrier margin coefficient named $\alpha $ , ratio of armature thickness to armature width named $\beta $ , ratio of armature height to armature width named $\gamma $ , and ratio of length of armature’s tail to armature height named $\kappa $ , equations of some key parameters of monolithic C-type armature in rectangular caliber railgun system are proposed. Based on analysis of mass of armature, electromagnetic contact force between armature and rail, mechanical strength of armature’s tail, and inductance gradient, relationship of some key parameters of monolithic C-type armature in rectangular caliber railgun system are proposed. Conclusion can be drawn that increase of $\theta $ can reduce mass of armature and improve mechanical strength of armature’s tail, but electromagnetic contact pressure between armature and rail will be decreased. Decrease of $\gamma $ could be a considerable way to remarkably increase inductance gradient, and then increase launch system efficiency.

Some Key Parameters of Different Caliber Solid-Armature Railgun Related to Linear Current Density

By introducing current carrier margin coefficient named $\alpha $ , ratio of armature thickness to armature width named $\beta $ , and ratio of armature height to armature width named $\gamma $ , equations of some key parameters of rectangular caliber railgun system, which is related to linear current density, are proposed. Then, some key parameters for different caliber railgun system are studied. Based on the analysis of electromagnetic contact pressure between armature and rail, $+ di/dt$ skin effect, velocity skin effect, and melt wear of armature, it can be obtained that current density of rail/armature interface is directly proportional to the linear current density. Thus, in order to decrease rail/armature interface current density, it is necessary to reduce linear current density. It can also be obtained that current density of rail/armature interface in current ramp-up is inversely proportional to the root of current rise time. Thus, it is necessary to increase current rise time to decrease rail/armature interface current density. Average melt wear rate of armature is directly proportional to the square of linear current density.

Research on key factors and their interaction effects of electromagnetic force of high-speed solenoid valve.

Analysis consisting of numerical simulations along with lab experiments of interaction effects between key parameters on the electromagnetic force based on response surface methodology (RSM) has been also proposed to optimize the design of high-speed solenoid valve (HSV) and improve its performance. Numerical simulation model of HSV has been developed in Ansoft Maxwell environment and its accuracy has been validated through lab experiments. Effect of change of core structure, coil structure, armature structure, working air gap, and drive current on the electromagnetic force of HSV has been analyzed through simulation model and influence rules of various parameters on the electromagnetic force have been established. The response surface model of the electromagnetic force has been utilized to analyze the interaction effect between major parameters. It has been concluded that six interaction factors including working air gap with armature radius, drive current with armature thickness, coil turns with side pole radius, armature thickness with its radius, armature thickness with side pole radius, and armature radius with side pole radius have significant influence on the electromagnetic force. Optimal match values between coil turns and side pole radius; armature thickness and side pole radius; and armature radius and side pole radius have also been determined.

Some Key Parameters for Rectangular Caliber Railgun System

Electromagnetic railgun is one of the most important new concept weapons. Some key parameters of a rectangular caliber railgun system—the thickness of the armature $d_{0}$ , the width of the caliber $X$ , the height of the caliber $Y$ , the minimum length of the rail $L$ , the amplitude of current $I$ , and the pulsewidth of current $t_{0}$ —are studied in this paper. By introducing the current carrier margin coefficient named $\alpha$ , the ratio of armature thickness to railgun caliber width named $\beta$ , and the ratio of caliber height to caliber width named $\gamma$ , equations of some key parameters of the rectangular caliber railgun system are proposed. Based on analysis of the armature's electric heating capacity and mass, 0.7 is an appropriate value for $\alpha$ . Based on analysis of parameters of railguns, $\beta = 1/3$ and $\gamma \leq 1$ are appropriate for small and medium calibers, and $\beta and $\gamma = 1$ are appropriate for large calibers.

Parameter studies for traveling wave coaxial launchers

The results of very extensive air-core coaxial launcher parameter studies performed using computers are reported. In the course of studying the feasibility of accelerating a 1 kg projectile to 10 km/s with an 18 m air-core multiphase coaxial launcher powered by rising frequency generators (RFGs), a complete simulation code based on the current filament method was developed. Results from the simulation code indicate rather chaotic behavior of an arbitrary coaxial launcher design. More fundamental studies were then conducted using various computer codes based on the current filament method. An extensive study was performed to analyze the variation of coaxial launcher behavior due to perturbations in launcher geometry such as pole pitch, coil, stator-coil thickness number of phases in the stator, and armature thickness, armature injection velocity, armature material properties, and stator current frequencies. A study using dimensionless parameters was performed on the relationship among stator-coil length, stator and armature radii, mutual inductance, and its gradient.< <ETX xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">&gt;</ETX>

Cooling for the armature windings in a repetitively fired air-core compulsator

A thermal model has been developed to analyze theoretically the cooling in the armature windings of a repetitively fired air-core compulsator. The model is used to predict the cooling effectiveness for helium gas flowing through small passages within the windings. The gas temperature, pressure, and velocity distributions along the coolant tube are predicted and the thermal diffusion inside the armature windings is then calculated. The cooling goal is to stabilize the temperature of the hottest spot on the armature at a given level, which is below the degradation temperature of epoxy, after nine shots. Radial heat diffusion in the combination of aluminium wires, epoxy, and tube dominates the heat transfer mechanisms and determines whether the cooling goal can be achieved. Thus the radial dimension is very critical, so it is important to minimize the armature thickness. >