Thermal Radiative Cooling Enabled Freeze Tweezer for Manipulating Micro Scale Objects

2011 ◽  
Author(s):  
Yang Yang ◽  
Jing Liu
Keyword(s):  
Numerical Simulation ◽  
Small Volume ◽  
Freezing Behavior ◽  
Cooling Effect ◽  
Radiative Cooling ◽  
Convective Cooling ◽  
Micro Scale

A freeze tweezer is a new kind of manipulation tool which employs the freezing force of a small volume of nucleotide ice for operating the micro-objects in an aqueous state. Previously, such typical device prototypes were respectively realized based on conductive and convective cooling effect. Aiming to present an alternative feasible way for realizing the freeze tweezer in micro or even much smaller size by thermal radiative cooling, a complete 3-D numerical simulation on the operation behaviors of such kind freeze tweezer have been implemented. As a result, the droplet freezing behavior is directly caused by the freeze tweezer rather than the thermal radiative cooling from the sidewall. It indicates that this new freeze tweezer would also complete all the functions as its previous type would achieve.

Effect of Cooling on the Aerodynamic Performance in the Intercooled Compressor Vanes

2017 ◽  
Author(s):  
Long-gang Liu ◽  
Xue-song Li ◽  
Xiao-dong Ren ◽  
Chun-wei Gu
Keyword(s):  
Numerical Simulation ◽  
Boundary Layer ◽  
Curve Surface ◽  
Aerodynamic Performance ◽  
Cooling Effect ◽  
Main Stream ◽  
Two Dimensional ◽  
Convective Cooling ◽  
Cooling Channels ◽  
Turbulent Separation

An intercooling technique using convective cooling channels in the compressor stator vanes has been proposed in recent years. In this paper, two cooling methods are presented and conjugate heat transfer method is used in the numerical simulation to study the effect of cooling on the laminar boundary layer and turbulent boundary layer in compressors. The overall performance of the compressor is also analyzed. A flat plate in T3C series experiments under adverse pressure gradient has been simulated to verify the aerodynamic simulation and preliminarily investigate the cooling effect. Subsequently, a two-dimensional compressor vane NACA65-(12A2I8b)10 has been numerically simulated to study the cooling effect on two-dimensional boundary layer of the curve surface. The numerical simulation results of the vane without cooling channel are in good agreement with the experiment data by NASA. By comparing it with the case which has convective cooling channels, it can be found that the cooling decreases the size of laminar separation bubble and delays the turbulent separation, which reduces the loss at both the design and off-design angle of attack. A three-dimensional highly-loaded five-stage axial compressor whose stator vanes have cooling channels and cooling endwalls has also been numerically simulated. The cooling channels and endwalls decrease the temperature rising of the main stream with a slight increase of the pressure rising, which indicates that this intercooling method can be used in the intercooled and recuperated (ICR) cycle. Cooling channels decrease the temperature of the stator vanes and protect them from the high temperature. Besides, the effect of cooling on the turbulent separation in the corner region has also been investigated. The cooling channels decrease the total pressure loss, which indicates that cooling has a beneficial effect on the aerodynamic performance of the compressor.

scholarly journals MEMS-Based Integrated Triaxial Electrochemical Seismometer

Micromachines ◽  
2021 ◽  
Vol 12 (10) ◽  
pp. 1156
Author(s):  
Wenjie Qi ◽  
Bowen Liu ◽  
Tian Liang ◽  
Jian Chen ◽  
Deyong Chen ◽  
...  
Keyword(s):  
Numerical Simulation ◽  
Ground Motion ◽  
Small Volume ◽  
Three Dimensional ◽  
Experimental Results ◽  
Good Prospect ◽  
High Symmetry ◽  
Noise Levels ◽  
Sensitivity Curves ◽  
Simulation Results

This paper presents a micro-electromechanical systems (MEMS)-based integrated triaxial electrochemical seismometer, which can detect three-dimensional vibration. By integrating three axes, the integrated triaxial electrochemical seismometer is characterized by small volume and high symmetry. The numerical simulation results inferred that the integrated triaxial electrochemical seismometer had excellent independence among three axes. Based on the experimental results, the integrated triaxial electrochemical seismometer had the advantage of small axial crosstalk and could detect vibration in arbitrary directions. Furthermore, compared with the uniaxial electrochemical seismometer, the integrated triaxial electrochemical seismometer had similar sensitivity curves ranging from 0.01 to 100 Hz. In terms of random ground motion response, high consistencies between the developed integrated triaxial electrochemical seismometer and the uniaxial electrochemical seismometer could be easily observed, which indicated that the developed integrated triaxial electrochemical seismometer produced comparable noise levels to those of the uniaxial electrochemical seismometer. These results validated the performance of the integrated triaxial electrochemical seismometer, which has a good prospect in the field of deep geophysical exploration and submarine seismic monitoring.

Huff and puff process optimization in micro scale by coupling laboratory experiment and numerical simulation

Fuel ◽  
2018 ◽  
Vol 224 ◽  
pp. 289-301 ◽  
Author(s):  
Damian Janiga ◽  
Robert Czarnota ◽  
Jerzy Stopa ◽  
Paweł Wojnarowski
Keyword(s):  
Numerical Simulation ◽  
Laboratory Experiment ◽  
Process Optimization ◽  
Micro Scale

scholarly journals Implementation of Surface Radiation and Fluid-Structure Thermal Coupling in Atmospheric Reentry

2012 ◽  
Vol 2012 ◽  
pp. 1-8 ◽  
Author(s):  
Ojas Joshi ◽  
Pénélope Leyland
Keyword(s):  
Numerical Simulation ◽  
Radiative Heating ◽  
Surface Radiation ◽  
Radiative Cooling ◽  
Thermal Coupling ◽  
Total Heat Flux ◽  
Hollow Cone ◽  
Atmospheric Reentry ◽  
Thermal Fields ◽  
Flap Region

During atmospheric reentry, radiative heating is one of the most important component of the total heat flux. In this paper, we investigate how the thermal radiation coming from the postshock region interacts with the spacecraft structure. A model that takes into account the radiation reflected by the surface is developed and implemented in a solid solver. A partitioned algorithm performs the coupling between the fluid and the solid thermal fields. Numerical simulation of a hollow cone head and a deployed flap region shows the effects of the radiative cooling and the significance of the surface radiation.

scholarly journals Modelling of textile composite reinforcements on the micro-scale

2014 ◽  
Vol 14 (1) ◽  
pp. 28-33 ◽  
Author(s):  
Oliver Döbrich ◽  
Thomas Gereke ◽  
Chokri Cherif
Keyword(s):  
Numerical Simulation ◽  
Finite Element Analysis ◽  
Computational Cost ◽  
Textile Composite ◽  
Element Analysis ◽  
Simulation Tools ◽  
Micro Scale ◽  
Generating Method ◽  
Geometrical Effects ◽  
Composite Reinforcements

Abstract Numerical simulation tools are increasingly used for developing novel composites and composite reinforcements. The aim of this paper is the application of digital elements for the simulation of the mechanical behaviour of textile reinforcement structures by means of a finite element analysis. The beneficial computational cost of these elements makes them applicable for the use in large models with a solution on near micro-scale. The representation of multifilament yarn models by a large number of element-chains is highly suitable for the analysis of structural and geometrical effects. In this paper, a unit cell generating method for technical reinforcement textiles, using digital elements for the discretization, is introduced.

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