The Design and Modeling of Jetting Dispenser Actuated by Dual Piezostack Actuator

2013 ◽  
Vol 433-435 ◽  
pp. 72-75 ◽  
Author(s):  
Jun Cheol Jeon ◽  
Quoc Hung Nguyen ◽  
Seung Bok Choi
Keyword(s):  
Fluid Dynamics ◽  
Time Domain ◽  
High Viscosity ◽  
Maximum Displacement ◽  
Return Spring ◽  
Lever Mechanism ◽  
Performance Results ◽  
Adhesive Fluid ◽  
Motion Amplitude ◽  
Piezostack Actuator

This article presents performance results of a novel jetting dispenser system actuated dual piezostack actuators. The proposed piezo jetting dispenser system consists of a couple of piezostack actuators, lever mechanism, and needle part. The proposed dispenser can provide a very small dispensing dot size of high viscous adhesive, 10,000cp at 100°C, at a high dispensing flow rate in semi-conductor packaging processes. After describing the mechanism and operating principle of the proposed dispenser, a mathematical model of the system is obtained by considering behaviors of the piezostack, the return spring, the dispensing needle, and the adhesive fluid dynamics. For the computer simulation, the specific geometric dimensions of the proposed jetting dispenser are chosen in order to achieve operation requirements: needle motion amplitude: up to 0.15 mm; operating frequency: up to 500 Hz. With the high viscosity conditions, the dispensed amount of the adhesive and the maximum displacement of the piezo and the needle at 500Hz are evaluated in time domain.

The Characteristics of Variable Speed Inchworm Stage Using Lever Mechanism by Different Materials

2008 ◽  
Vol 8 (11) ◽  
pp. 5696-5701 ◽  
Author(s):  
Yong Woo Kim ◽  
Soo Chang Choi ◽  
Jeong Woo Park ◽  
Yoong Ho Jung ◽  
Deug Woo Lee
Keyword(s):  
Dynamic Range ◽  
Input Voltage ◽  
Variable Speed ◽  
Output Displacement ◽  
Output Force ◽  
Ultra Precision ◽  
Lever Mechanism ◽  
Feeding Speed ◽  
Performance Results ◽  
High Output

Currently, piezoelectric actuators which have attractive features such as high output force, high positioning resolution, high stiffness and quick response have been used in many ultra precision stages. But their positioning ranges are very small. This very limited displacement severely restricts the actuator's immediate implementation for long-range positioning. This paper shows a variable speed inchworm type stage with hinge structures as lever mechanism for nanometer resolution with large dynamic range and studies on characteristics of it. The inchworm stage has hinge structure levers which can shift their pivot position. And it can amplify/reduce output displacement using mechanical advantage with a lever. Especially we suggest guide-line of design according this work that was performed using different materials of stages (Aluminium and Stainless Steel). As the results of simulations, the larger lever ratio is, the smaller stiffness of lever portion is. As the results of experiments, when we input voltage into the inchworm stage, output displacement of each lever is different according to material. Hysteresis of stage could also present that grow according as lever rate rises and stiffness of material. In the case of feeding speed, Aluminium with less hardness showed excellent responsiveness, hence excellent feed performance results.

OPTIMIZATION AND PROFILING OF THE CACHE PERFORMANCE OF PARALLEL LATTICE BOLTZMANN CODES

2003 ◽  
Vol 13 (04) ◽  
pp. 549-560 ◽  
Author(s):  
THOMAS POHL ◽  
MARKUS KOWARSCHIK ◽  
JENS WILKE ◽  
KLAUS IGLBERGER ◽  
ULRICH RÜDE
Keyword(s):  
Fluid Dynamics ◽  
Computational Fluid Dynamics ◽  
Lattice Boltzmann ◽  
Parallel Computers ◽  
Optimization Techniques ◽  
Main Memory ◽  
Lattice Boltzmann Methods ◽  
Hierarchical Memory ◽  
Performance Results ◽  
2D And 3D

When designing and implementing highly efficient scientific applications for parallel computers such as clusters of workstations, it is inevitable to consider and to optimize the single-CPU performance of the codes. For this purpose, it is particularly important that the codes respect the hierarchical memory designs that computer architects employ in order to hide the effects of the growing gap between CPU performance and main memory speed. In this article, we present techniques to enhance the single-CPU efficiency of lattice Boltzmann methods which are commonly used in computational fluid dynamics. We show various performance results for both 2D and 3D codes in order to emphasize the effectiveness of our optimization techniques.

Shock Analysis and Design Method of Vibration Isolating System in the Time Domain

2005 ◽  
Author(s):  
Yinglong Zhao ◽  
Lin He ◽  
Zhiqiang Lv ◽  
Yu Wang
Keyword(s):  
Dynamic Analysis ◽  
Time Domain ◽  
Design Analysis ◽  
Analysis Method ◽  
Maximum Displacement ◽  
Element Analysis ◽  
Protection Measures ◽  
Analysis And Design ◽  
Shock Protection ◽  
The Time Domain

Choosing the equipment with good shock-resistant performance and taking shock protection measures while designing the onboard settings, the safety of onboard settings can be assured when warships, especially submarine subjected to non-contact underwater explosion, that is, these means can be used to limit the rattlespace (i.e., the maximum displacement of the equipment relative to the base) and the peak acceleration experienced by the equipment. Using shock-resistant equipments is one of shock protection means. The shock-resistant performance of the shock-resistant equipments should be verified in the design phase of the equipments. The shock design analysis methods used before and now includes shock design number method (static g-method), dynamic analysis in the time domain and dynamic design analysis method (DDAM). The FEA (Finite Element Analysis) software, for example, MSC.NASTRAN®, can be used for shock design analysis of the shock-resistant equipments. MSC.NASTRAN are used for shock design analysis of floating raft vibration isolating equipment with dynamic analysis method in the time domain in this paper, and the analysis results are in agreement with the test results. The shock design analysis method used in this paper can be used to analyze the shock-resistant performance of onboard shock-resistant equipments.

Computational Fluid Dynamics-Based Numerical Analysis of Acoustic Attenuation and Flow Resistance Characteristics of Perforated Tube Silencers

2013 ◽  
Vol 136 (2) ◽  
Author(s):  
Chen Liu ◽  
Zhenlin Ji
Keyword(s):  
Fluid Dynamics ◽  
Computational Fluid Dynamics ◽  
Pressure Drop ◽  
Time Domain ◽  
Transmission Loss ◽  
Air Flow ◽  
Acoustic Attenuation ◽  
Pressure Drops ◽  
Wave Range ◽  
Perforated Tube

The 3D time-domain computational fluid dynamics (CFD) approach is used to calculate the acoustic attenuation performance of perforated tube silencers without and with flow. For the crossflow perforated tube silencer and straight-through perforated tube silencers, the transmission loss predictions agree well with the experimental measurements available in the literature. Then, the 3D time-domain CFD approach is employed to investigate the effects of flow velocity and temperature on the acoustic attenuation performance of perforated tube silencers. The numerical results demonstrated that the transmission loss is increased at most frequencies for the crossflow perforated tube silencer as the air flow increases, while the air flow has little influence on the acoustic attenuation in the plane wave range and increases the acoustic attenuation at higher frequencies for the straight-through perforated tube silencers. Increasing the air temperature shifts the transmission loss curve to higher frequency and lowers the resonance peaks somewhat. The pressure drops of perforated tube silencers are predicted by performing the 3D steady flow computation using CFD. The pressure drop of the crossflow perforated tube silencer is much higher than those of the straight-through perforated tube silencer at the same flow conditions, and the pressure drop of the straight-through perforated tube silencer increases gradually as the porosity increases.

Modification of the Dual Kelvin-Voigt/Maxwell Rheological Behavior for Antiseismic Hydraulic Dampers

2013 ◽  
Vol 430 ◽  
pp. 312-316 ◽  
Author(s):  
Polidor Bratu
Keyword(s):  
Dynamic Response ◽  
Time Domain ◽  
Rheological Behavior ◽  
Silicone Oil ◽  
Dissipative Function ◽  
Maxwell System ◽  
Behavioral Differences ◽  
Maximum Displacement ◽  
Hydraulic Damper ◽  
The Time Domain

The dissipative function is presented, depending on stiffness and maximum displacement, for a hydraulic damper with silicone oil at an exterior excitation type shock, applied in the time domain. For the same constructive solution, silicone hydraulic oil, the same structural mechanic elements, but with different settings/adjustments, one can model the rheological system Kelvin-Voigt, as well as the Maxwell system. In this context, the main behavioral differences in dynamic response will be presented, as well as the stiffness, dissipation and displacement during the applied shock parameters.

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