scholarly journals Design and Simulation of Electromagnetic Linear Actuators for Jet Dispensers

2020 ◽  
Vol 10 (5) ◽  
pp. 1653
Author(s):  
Minh-Sang Tran ◽  
Sheng-Jye Hwang
Keyword(s):  
Thrust Force ◽  
Inertia Force ◽  
Resistance Force ◽  
Driving Frequency ◽  
Excitation Current ◽  
Damping Force ◽  
Element Analysis ◽  
Spring Force ◽  
Return Spring ◽  
Linear Actuators

Three electromagnetic-based linear actuators, namely a solenoid actuator (SA), a moving coil actuator (MCA), and a moving magnet actuator (MMA), are proposed for driving the needle in a jet dispenser. The total resistance force acting on the needle during operation, including the damping force, the friction force, the inertia force, the compression spring force, and the backpressure, are measured by an experimental model. The thrust force required to overcome this resistance force is then predicted for each actuator using finite element analysis (FEA) simulations. Simple two-dimensional models of the SA, MCA, and MMA are constructed using the same coil dimensions in every case in order to facilitate an objective comparison between them. Simulations in ANSYS Maxwell software are then performed to adjust the specific dimensions of each actuator structure in such a way as to generate the thrust force required to drive the needle in the jet dispenser with the minimum excitation current possible. The simulation results show that for a maximum needle driving frequency of 250 Hz and a stroke length of 0.5 mm, the excitation current required to generate the necessary thrust force is equal to 1.8 A and 1.9 A for the MCA and MMA models, respectively, when a return spring is not used, and 2.2 A, 3.8 A, and 4.1 A for the SA, MCA, and MMA models, respectively, when a return spring is employed. It is additionally shown that the thrust force drop of the MCA and MMA models is far less than that of the SA model, about 0.7%, 1.8%, and 61% for three models, respectively. Three preliminary designs for jet dispensers incorporating the proposed actuators are also generated for reference purposes.

scholarly journals Viscoelastic analysis of Calving Glaciers

1980 ◽  
Vol 1 ◽  
pp. 37-41 ◽  
Author(s):  
D. V. Reddy ◽  
W. Bobby ◽  
M. Arockiasamy ◽  
R. T. Dempster
Keyword(s):  
Finite Element ◽  
Sea Water ◽  
Water Pressure ◽  
Computer Code ◽  
Ice Shelf ◽  
Element Analysis ◽  
Ice Shelves ◽  
Shear Moduli ◽  
Relaxation Functions ◽  
Spring Force

Calving of floating ice shelves is studied by a viscoelastic finite-element analysis. The fan-shaped breaking-up of glaciers due to forces that cause bending on creeping ice is assumed to be axisymmetric. Bending may be due to geometry of the bcdrock, action of tides and waves, and imbalance (at the ice front) between the stress in the ice and the sea-water pressure.The bulk and shear moduli of the ice are represented by relaxation functions of the Prony series, which is a discrete relaxation spectrum composed of a constant and a summation of exponential terms. These properties are also functions of temperature, that varies over the thickness of the ice shelf. The temperature distribution across the thickness of the ice is obtained from calculations based on a linear dependence of thermal conductivity on the temperature. Numerical results are presented for various calving mechanisms. A computer code, VISIC1, is developed by modifying a finite-element viscoelastic code, VISICE, for floating ice islands. The buoyancy of the water is taken into account by a Winkler spring model, with the spring force determined from displaced volume. Locations of crack initiation obtained from the analysis are used to predict the iceberg size immediately after calving.

scholarly journals On the substantiation of the effectiveness of air-centrifugal separation and dust cleaning of seed heap of herbs after the grate device

2019 ◽  
pp. 80-85
Author(s):  
Tverdokhlib Igor ◽  
Spirin Anatoly
Keyword(s):  
Seed Production ◽  
Air Flow ◽  
Inertia Force ◽  
Resistance Force ◽  
Centrifugal Separation ◽  
Separation Unit ◽  
Production Technologies ◽  
Assembly Technology ◽  
One Machine

The agrobiological and physico-mechanical properties of leguminous seed plants do not allow them to be harvested without loss exclusively by combine technologies. One way to increase the productivity of the seed production process is to include stationary machines in the assembly technology for wiping and separating seed heaps. Combining these important operations with one machine will further increase the efficiency of legume seed production technologies. This work is devoted to considering ways to increase the efficiency of air-centrifugal separation and dust cleaning seed heaps. A review of recent studies and publications has shown that there is a sufficient methodological basis for determining the parameters of the process of separation of the heap and purification of the exhaust air. An analysis of the publications made it possible to determine the purpose of the research, which is to increase the efficiency of the grater-separation unit by substantiating its scheme and the method of theoretical determination of the parameters of the separation process. According to the results of previous studies, a structural scheme of the grater-separating device is proposed. The main elements of the block are a grater device, which consists of a motionless and movable corrugated discs of the separating device with separate channels for the exit of seeds, straw part of the heap, air. To increase the efficiency of the cleaning process, a blade swirler and a louvre nozzle are placed in the separating device, which provide the air flow with rotational movement around the axis of the cyclone body. In theoretical studies of the motion of particles in a rotational air flow, the simplified assumption was adopted: the particles are spherical, do not deform, and do not interact with each other, the inertia force is directed along the radius of the cyclonic chamber, the tangential and axial components of the particle velocity are equal to the corresponding components of the air velocity, and the particle resistance force determined by the Stokes law, the force of attraction is much less than the centrifugal force, so we neglect it. The obtained formulas allow one to approximately determine the parameters of the cyclone device that will ensure the separation of the seeds of legumes.

A Landing Gear Drop Dynamic Simulation Based on the LMS. Virtual. Lab

2011 ◽  
Vol 55-57 ◽  
pp. 684-687
Author(s):  
Li Zhang ◽  
Cai Jun Xue
Keyword(s):  
Influence Factors ◽  
Landing Gear ◽  
Buffer System ◽  
Air Spring ◽  
Damping Force ◽  
Tire Force ◽  
Virtual Lab ◽  
Spring Force ◽  
Simulation Based ◽  
Fluid Damping

In order to evaluate the dynamic behavior of the buffer of the Seagull 300 aircraft’s main landing gear, a drop model is built to simulate the drop dynamics using the software of LMS Virtual Lab Motion. The fluid damping force of the buffer, the air spring force of the buffer, the tire force of the landing gear and the weight of the fuselage are considered in the model. The simulation results are compared with the results of the Seagull 300 landing gears drop test, which proves the accuracy of the simulation model. Then the buffer performance and its influence factors are computationally discussed. This method gives a new way to study and improve the performance of the buffer system of an aircraft.

scholarly journals Comparison of the Stator Step Skewed Structures for Cogging Force Reduction of Linear Flux Switching Permanent Magnet Machines

Energies ◽  
2018 ◽  
Vol 11 (8) ◽  
pp. 2172 ◽  
Author(s):  
Wenjuan Hao ◽  
Yu Wang
Keyword(s):  
Finite Element Analysis ◽  
System Performance ◽  
Thrust Force ◽  
Low Cost ◽  
Good Choice ◽  
Permanent Magnet Machines ◽  
Maximum Difference ◽  
Element Analysis ◽  
Rotary Machines ◽  
Force Reduction

Linear flux switching permanent magnetic (LFSPM) machines, with the armature windings and magnets both on the mover in addition to a robust stator, are a good choice for long stoke applications, however, a large cogging force is also inevitable due to the double salient structure, and will worsen the system performance. Skewing methods are always employed for the rotary machines to reduce the cogging torque, and the rotor step-skewed method is a low-cost approximation of regular skewing. The step skewed method can also be applied to the linear machines, namely, the stator step skewed. In this paper, three stator step skewed structures, which are a three-step skewed stator, a two-step skewed stator and an improved two-step skewed stator, are employed for the cogging force reduction of two types of LFSPM machines. The three structures are analyzed and compared with emphasize on the influence of the skewed displacement on the cogging force and the average thrust force. Based on finite element analysis (FEA), proper skewed displacements are selected according to maximum difference between the reduction ratio of the cogging force and the decrease ratio of the average thrust force, then, the corresponding results are compared, and finally, valuable conclusions are drawn according to the comparison. The comparison presented in this paper will be useful to the cogging force reduction of LFSPM machines in general.

Study of Electrostatic-Induced Jumping Droplets on Superhydrophobic Surfaces

2017 ◽  
Author(s):  
B. Traipattanakul ◽  
C. Y. Tso ◽  
Christopher Y. H. Chao
Keyword(s):  
Heat Transfer ◽  
High Speed ◽  
Electrostatic Force ◽  
Droplet Radius ◽  
Inertia Force ◽  
Resistance Force ◽  
Average Charge ◽  
Electrical Voltage ◽  
Fluid Systems ◽  
Set Up

Condensation of water vapor is an important process utilized in energy/thermal/fluid systems. When droplets coalesce on the non-wetting surface, excess surface energy converts to kinetic energy leading to self-propelled jumping of merged droplets. This coalescing-jumping-droplet condensation can better enhance heat transfer compared to classical dropwise condensation and filmwise condensation. However, the resistance force can cause droplets to return to the surface. These returning droplets can either coalesce with neighboring droplets and jump again, or adhere to the surface. As time passes, these adhering droplets can become larger leading to progressive flooding on the surface, limiting heat transfer performance. However, an electric field is known to be one of the effective methods to prevent droplet return and to address the progressive flooding issue. Therefore, in this study, an experiment is set up to investigate the effects of applied electrical voltages between two parallel copper plates on the jumping height with respect to the droplet radius and to determine the average charge of coalescing-jumping-droplets. Moreover, the gravitational force, the drag force, the inertia force and the electrostatic force as a function of the droplet radius are also discussed. The gap width of 7.5 mm and the electrical voltages of 50 V, 100 V and 150 V are experimentally investigated. Droplet motions are captured with a high-speed camera and analyzed in sequential frames. The results of the study show that the applied electrical voltage between the two plates can reduce the resistance force due to the droplet’s inertia and can increase the effects of the electrostatic force. This results in greater jumping heights and the jumping phenomenon of some bigger-sized droplets. With the same droplet radius, the greater the applied electrical voltage, the higher the coalescing droplet can jump. This work can be utilized in several applications such as self-cleaning, thermal diodes, anti-icing and condensation heat transfer enhancement.

Chatter Stability Prediction of Cutting Process With Process Damping Utilizing Finite Element Analysis

2020 ◽  
Author(s):  
Norikazu Suzuki ◽  
Tomoki Nakanomiya ◽  
Eiji Shamoto
Keyword(s):  
Finite Element Analysis ◽  
Finite Element ◽  
Vibration Amplitude ◽  
Cutting Process ◽  
Force Model ◽  
Chatter Stability ◽  
Chatter Vibration ◽  
Damping Force ◽  
Element Analysis ◽  
Process Damping

Abstract This paper presents a new approach to predict chatter stability in cutting considering process damping. Traditional chatter stability analysis methods enable to predict stable or unstable conditions. Under unstable conditions, the chatter vibration can increase theoretically infinitely. However, chatter vibration is damped at a certain amplitude in real process due to process damping, i.e., the cutting process is stabilized by means of tool flank face contact to the machined surface. In order to consider the influence of the process damping, a simple process damping force model is introduced. The process damping force is assumed to be proportional to the structural displacement. The process damping coefficient is a function of the vibration amplitude and the wavelength. In order to identify the coefficients, a series of finite element analysis is conducted in the present study. Identified coefficients are introduced into the conventional zero-order-solution in frequency domain. The proposed model calculates chatter stability limit assuming process damping with finite amplitude. Hence, this analysis enables to estimate the amplitude-dependent quasi-stable conditions. Analytical results for thee face turning operation demonstrated influence of process damping effect on resultant vibration amplitude quantitatively.

Simulation Analysis of Aviation Aluminum Alloy Reaming Processes by Using PCD Reamer

2020 ◽  
Vol 866 ◽  
pp. 3-11
Author(s):  
J. Yin ◽  
W. Yang ◽  
Yong Guo Wang
Keyword(s):  
Aluminum Alloy ◽  
Cutting Force ◽  
Thrust Force ◽  
Simulation Analysis ◽  
Cutting Temperature ◽  
Spindle Speed ◽  
Analysis Software ◽  
Element Analysis ◽  
Speed Increase ◽  
Cutting Processes

Cutting force and cutting temperature are two important parameters in the cutting processes. In this paper, AdvantEdge finite element analysis software was used to simulate and analyze the reaming process of aviation aluminum alloy 7050 by using PCD reamer. The cutting simulation model was established to investigate the effect of spindle speed, feed per tooth on thrust force and cutting temperature. Simulation results showed that the cutting force increased with the increase of feed per tooth at different spindle speeds. And in the case of different feed per tooth, the cutting force decreased slightly as the spindle speed increase. Besides, from the cutting temperature distributed in the reamer, the cutting temperature near the tip of the tool in the reaming process was highest, the cutting temperature increased with the increase of both spindle speed and feed per tooth.

OPTIMIZATION OF THE FORCE CHARACTERISTIC OF ROTARY MOTION TYPE OF ELECTROMAGNETIC ACTUATOR BASED ON FINITE ELEMENT ANALYSIS

2016 ◽  
Vol 78 (9) ◽  
Author(s):  
Izzati Yusri ◽  
Mariam Md Ghazaly ◽  
Esmail Ali Ali Alandoli ◽  
Mohd Fua'ad Rahmat ◽  
Zulkeflee Abdullah ◽  
...  
Keyword(s):  
Finite Element Analysis ◽  
Finite Element ◽  
Permanent Magnet ◽  
Permanent Magnets ◽  
Thrust Force ◽  
Rotary Motion ◽  
Electromagnetic Actuator ◽  
Element Analysis ◽  
Electromagnetic Actuators ◽  
Motion Type

This paper addresses a rotary motion type of electromagnetic actuator that compares two types of electromagnetic actuators; i.e the Permanent Magnet Switching Flux (PMSF) and the Switching Reluctance (SR) actuator. The Permanent Magnet Switching Flux (PMSF) actuator is the combination of permanent magnets (PM) and the Switching Reluctance (SR) actuator. The force optimizations are accomplished by manipulating the actuator parameters; i.e. (i) the poles ratio of the stator and rotor; (ii) the actuator’s size; (iii) the number of winding turns; and (iv) the air gap thickness between the stator and rotor through Finite Element Analysis Method (FEM) using the ANSYS Maxwell 3D software. The materials implemented in the actuator’s parameters optimizations are readily available materials, especially in Malaysia. The excitation current used in FEM analysis for both actuators was between 0A and 2A with interval of 0.25A. Based on the FEM analyses, the best result was achieved by the Permanent Magnet Switching Flux (PMSF) actuator. The PMSF actuator produced the largest magnetostatic thrust force (4.36kN) once the size is scaled up to 100% with the input current, 2A respectively. The maximum thrust force generated by the Switching Reluctance (SR) actuator was 168.85μN, which is significantly lower in compared to the results of the PMSF actuator. 

scholarly journals Design of a 3-RPR Flexure System for Optical Switch Assembly

2020 ◽  
Vol 2020 ◽  
pp. 1-9
Author(s):  
Guiyue Kou ◽  
Mouyou Lin ◽  
Changbao Chu
Keyword(s):  
Permanent Magnets ◽  
Optical Switch ◽  
Low Cost ◽  
Mechanical Vibration ◽  
Analytical Models ◽  
Assembly System ◽  
Sensors And Actuators ◽  
Damping Force ◽  
Element Analysis ◽  
Compact Size

In the MEMS optical switch assembly, the collision is likely to happen between the optical fiber and the U-groove of the chip due to the uncontrollable assembly errors. However, these errors can hardly be completely eliminated by the active control using high precision sensors and actuators. It will cause the large acting force and part damage, which further leads to the assembly failure. To solve this question, this paper presents a novel low-cost three-degree-of-freedom (three-DOF) passive flexure system to adaptively eliminate the planar assembly errors. The flexure system adopts three parallel kinematic chains with a novel 3-RPR structure and has a compact size with a diameter of 125 mm and thickness of 12 mm. A novel eddy current damper with the structure of Halbach array permanent magnets (PMs) is utilized to suppress the adverse mechanical vibration of the assembly system from the background disturbances. Analytical models are established to analyze the kinematic, static, and dynamic performances of the system in detail. Finally, finite element analysis is adopted to verify the established models for optimum design. The flexure system can generate a large deformation of 1.02 mm along the two translational directions and 0.02° along the rotational direction below the yield state of the material, and it has much higher natural frequencies than 200 Hz. Moreover, the large damping force means that the designed ECD can suppress the system vibration quickly. The above results indicate the excellent characteristics of the assembly system that will be applied into the optical switch assembly.

Force Reduction by Motion Design in Spring-Loaded Cam Mechanisms

1984 ◽  
Vol 106 (3) ◽  
pp. 278-284 ◽  
Author(s):  
R. C. Johnson
Keyword(s):  
Contact Force ◽  
High Speed ◽  
Critical Force ◽  
Inertia Force ◽  
Motion Synthesis ◽  
Spring Force ◽  
Force Reduction ◽  
Motion Design

A strategy of motion synthesis is developed for reducing critical forces in relatively rigid high-speed spring-loaded cam mechanisms. A special motion is specifically presented to illustrate application of the developed strategy, for the dwell-rise-dwell displacement case. Critical force graphs are presented for a numerical industrial probelm in three examples, comparing the developed special motion with the commonly used cycloidal and modified trapezoidal motions. Maximum values of cam contact force, inertia force, and spring force are all appreciably reduced by the special motion.

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