Partial Stochastic Linearization of a Spherical Pendulum With Coriolis Damping Produced by Radial Spring and Damper

2015 ◽  
Vol 137 (5) ◽  
Author(s):  
L. D. Viet
Keyword(s):  
Numerical Simulation ◽  
Stochastic Analysis ◽  
Radial Direction ◽  
Spherical Pendulum ◽  
Analysis And Design ◽  
Partial Linearization ◽  
System A ◽  
Stochastic Linearization ◽  
Linearized System ◽  
Sway Motion

This study considers the stochastic analysis of a spherical pendulum, whose bidirectional vibration is reduced by spring and damper installed in the radial direction between the point mass and the cable. Under sway motion, the centrifugal force results in the radial motion, which in its turn produces the Coriolis force to reduce sway motion. In stochastic analysis and design, the problem is that the Monte Carlo simulation is time-consuming, while the full stochastic linearization totally fails to describe the effectiveness of the spring and damper. We propose the partial linearization applied to the Coriolis damping to overcome the disadvantages of two mentioned methods. Moreover, the proposed technique can give the analytical solution of partial linearized system. A numerical simulation is performed to verify the proposed approach.

Numerical Simulation on the Temperature Characteristics of Indirect Air Cooling System

2015 ◽  
Vol 741 ◽  
pp. 536-540
Author(s):  
Xiao Zhi Qiu ◽  
Yan Ming Zhao ◽  
Bao Hua Huang ◽  
Wei Xu
Keyword(s):  
Numerical Simulation ◽  
Wind Speed ◽  
Cooling System ◽  
System Change ◽  
Temperature Characteristic ◽  
Air Cooling ◽  
Ansys Software ◽  
System A ◽  
Air Cooling System ◽  
Simulation Results

Based on the analysis of indirect air cooling system, a numerical simulation model of indirect air cooling system was constructed by ANSYS software. According to the different wind speed condition, the temperature characteristic of indirect air cooling system was analyzed. The simulation results show that with the increase of wind speed, the ventilation and heat release of the indirect air cooling system change greatly. It provides a theoretical basis for the design of the wind-proof device of indirect air cooling system.

SAMS: Stochastic Analysis With Minimal Sampling—A Fast Algorithm for Analysis and Design Under Uncertainty

2004 ◽  
Vol 127 (4) ◽  
pp. 558-571 ◽  
Author(s):  
A. Mawardi ◽  
R. Pitchumani
Keyword(s):  
System Performance ◽  
Stochastic Analysis ◽  
Sampling Method ◽  
Latin Hypercube Sampling ◽  
Analysis And Design ◽  
Process Outcomes ◽  
Input Parameters ◽  
Computationally Intensive ◽  
Uncertain Input ◽  
Reliability And Robustness

Design of processes and devices under uncertainty calls for stochastic analysis of the effects of uncertain input parameters on the system performance and process outcomes. The stochastic analysis is often carried out based on sampling from the uncertain input parameters space, and using a physical model of the system to generate distributions of the outcomes. In many engineering applications, a large number of samples—on the order of thousands or more—is needed for an accurate convergence of the output distributions, which renders a stochastic analysis computationally intensive. Toward addressing the computational challenge, this article presents a methodology of S̱tochastic A̱nalysis with M̱inimal S̱ampling (SAMS). The SAMS approach is based on approximating an output distribution by an analytical function, whose parameters are estimated using a few samples, constituting an orthogonal Taguchi array, from the input distributions. The analytical output distributions are, in turn, used to extract the reliability and robustness measures of the system. The methodology is applied to stochastic analysis of a composite materials manufacturing process under uncertainty, and the results are shown to compare closely to those from a Latin hypercube sampling method. The SAMS technique is also demonstrated to yield computational savings of up to 90% relative to the sampling-based method.

scholarly journals Numerical Simulation of Diffusion Absorption Refrigerator

2021 ◽  
Vol 233 ◽  
pp. 01044
Author(s):  
Guoyan Zhang ◽  
Shengyong Liu ◽  
Jie Lu ◽  
Jiong Wang ◽  
Yongtao Ma
Keyword(s):  
Numerical Simulation ◽  
Mathematical Model ◽  
Gas Phase ◽  
Radial Direction ◽  
Tube Length ◽  
Lifting Capacity ◽  
Fluent Software ◽  
Lower Temperature ◽  
Absorption Refrigerator ◽  
Diffusion Absorption

Based on Fluent software, a mathematical model of thermosyphon pump is established and numerical simulation is carried out to study the influence of riser tube length, tube diameter and immersion ratio on liquid lifting capacity and efficiency. The results showed that: the liquid lifting volume increased with the increase of immersion ratio, whereas the lifting efficiency showed a trend of increasing followed by decreasing. The highest lifting efficiency for a 340mm long, 6mm diameter riser achieved when the immersion ratio is 0.35. With the increasing of the height in riser, the velocity of the gas phase close to the wall in the thermosyphon pump was higher than the velocity along the radial direction. In order to enhance fluid interchange, corners of the refrigeration box were designed to be arc-shaped with a higher corner speed and lower temperature.

Numerical simulation of the aqueous humor flow in the eye drainage system; a healthy and pathological condition comparison.

2020 ◽  
Vol 83 ◽  
pp. 82-92 ◽  
Author(s):  
G.J. Martínez Sánchez ◽  
C. Escobar del Pozo ◽  
J.A. Rocha Medina ◽  
J. Naude ◽  
A. Brambila Solorzano
Keyword(s):  
Numerical Simulation ◽  
Aqueous Humor ◽  
Pathological Condition ◽  
Drainage System ◽  
Aqueous Humor Flow ◽  
System A

scholarly journals Numerical Simulation of the Air Cooling System for Scientific Payload Rack on a Space Station

Energies ◽  
2020 ◽  
Vol 13 (22) ◽  
pp. 6145
Author(s):  
Yuan-Yuan Lou ◽  
Ben-Yuan Cai ◽  
Yun-Ze Li ◽  
Jia-Xin Li ◽  
En-Hui Li
Keyword(s):  
Numerical Simulation ◽  
Cooling System ◽  
Space Station ◽  
Thermal Control ◽  
Physical Models ◽  
Air Cooling ◽  
Ansys Fluent ◽  
System A ◽  
Air Cooling System ◽  
Scientific Payload

The space scientific payload rack is a multifunctional experimental platform, and the requirements of the environmental temperature index are different for diversified experimental modules inside. The air cooling system is an important part of the rack thermal control system. A new type of air cooling system with small size and flexible arrangement is proposed in this paper, that is, micro air ducts with pinhole-sized air vents. The rack physical models of new and traditional air cooling modes are established, respectively. The numerical simulation of the inner air flow is carried out by Ansys Fluent CFD software (Ansys Inc., Canonsburg, PA, USA), which verifies that compared with the traditional method, the temperature field and flow field of the new air cooling method are more uniform, and the heat sources located at the edge of the rack can also be cooled better.

Numerical Simulation on Dynamic Behavior of Intermittent Roller Chain Drives

2012 ◽  
Vol 155-156 ◽  
pp. 535-539 ◽  
Author(s):  
Li Xin Xu ◽  
Yong Gang Li
Keyword(s):  
Numerical Simulation ◽  
Dynamic Behavior ◽  
Simulation Analysis ◽  
Longitudinal Vibration ◽  
Three Dimension ◽  
Chain Drive ◽  
Rigid Body Dynamic ◽  
Analysis And Design ◽  
Roller Chain ◽  
Chain Drives

A detailed numerical simulation analysis on the dynamic response of intermittent roller chain drive has been carried out in this study. Instead of using analytical method, three dimension solid modeling software and multi-rigid body dynamic analysis software are utilized for modeling and simulating the dynamic behavior of chain drive. The longitudinal vibration response of the chain links is concentrated on, which aims to reveal the dynamic characteristics of the intermittent chain drive under varying motion laws such as the modified sinusoid (MS), the modified constant velocity (MCV) and the unsymmetrical modified trapezoid (UMT). The simulation results can enable designers to require information on the analysis and design of mechanisms with the intermittent roller chain drives.

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