Design and Analysis of Thermal-Bubble-Based Micromachined Accelerometer

Volume 3 ◽  
2004 ◽  
Author(s):  
Ke-Min Liao ◽  
Rongshun Chen ◽  
Bruce C. S. Chou
Keyword(s):  
Heat Transfer ◽  
Fluid Flow ◽  
Velocity Field ◽  
Numerical Simulations ◽  
Frequency Response ◽  
Proof Mass ◽  
Flow Behavior ◽  
High Sensitivity ◽  
The Other ◽  
High Flux

In this study, a novel thermal-bubble-based micromachined accelerometer with advantages of no proof mass, preferable frequency response, and high sensitivity is presented. Unlike the other techniques, the only moving element in the proposed device is a small thermal-bubble created by using a high flux heater to vaporize the liquid contained in the micro chamber. In order to improve the performance of the accelerometer, the basic physical characteristics of this sensor have been analyzed. Numerical simulations are conducted to study the heat transfer and fluid flow behavior of the device and to demonstrate the feasibility of our design. The temperature profile and the velocity field distribution under different applied acceleration have been acquired. Moreover, a method for manufacturing the accelerometer by using the techniques of micromachining is provided and the performance of the presented design has been examined. The results concluded that the proposed design has better response and sensitivity comparing to its counterparts.

scholarly journals Microtomography-based numerical simulations of heat transfer and fluid flow through β -SiC open-cell foams for catalysis

2016 ◽  
Vol 278 ◽  
pp. 350-360 ◽  
Author(s):  
Xiaolei Fan ◽  
Xiaoxia Ou ◽  
Fei Xing ◽  
Glen A. Turley ◽  
Petr Denissenko ◽  
...  
Keyword(s):  
Heat Transfer ◽  
Fluid Flow ◽  
Numerical Simulations ◽  
Open Cell ◽  
Flow Through ◽  
Open Cell Foams

scholarly journals Effects of Rotation on Transient Fluid Flow and Heat Transfer Through a Curved Square Duct: The Case of Negative Rotation

2021 ◽  
Vol 26 (4) ◽  
pp. 29-50
Author(s):  
Mohammad Sanjeed Hasan ◽  
Md. Tusher Mollah ◽  
Dipankar Kumar ◽  
Rabindra Nath Mondal ◽  
Giulio Lorenzini
Keyword(s):  
Heat Transfer ◽  
Fluid Flow ◽  
Secondary Flow ◽  
Flow Behavior ◽  
Square Duct ◽  
Curvature Effects ◽  
Flow And Heat Transfer ◽  
Curved Duct ◽  
Wide Range ◽  
Mechanical Devices

Abstract The fluid flow and heat transfer through a rotating curved duct has received much attention in recent years because of vast applications in mechanical devices. It is noticed that there occur two different types of rotations in a rotating curved duct such as positive and negative rotation. The positive rotation through the curved duct is widely investigated while the investigation on the negative rotation is rarely available. The paper investigates the influence of negative rotation for a wide range of Taylor number (−10 ≤ Tr ≤ −2500) when the duct itself rotates about the center of curvature. Due to the rotation, three types of forces including Coriolis, centrifugal, and buoyancy forces are generated. The study focuses and explains the combined effect of these forces on the fluid flow in details. First, the linear stability of the steady solution is performed. An unsteady solution is then obtained by time-evolution calculation and flow transition is determined by calculating phase space and power spectrum. When Tr is raised in the negative direction, the flow behavior shows different flow instabilities including steady-state, periodic, multi-periodic, and chaotic oscillations. Furthermore, the pattern variations of axial and secondary flow velocity and isotherms are obtained, and it is found that there is a strong interaction between the flow velocities and the isotherms. Then temperature gradients are calculated which show that the fluid mixing and the acts of secondary flow have a strong influence on heat transfer in the fluid. Diagrams of unsteady flow and vortex structure are further sketched and precisely elucidate the curvature effects on unsteady fluid flow. Finally, a comparison between the numerical and experimental data is discussed which demonstrates that both data coincide with each other.

scholarly journals Numerical Analysis of SiO2 Nanofluid Performance in Serpentine PEMFC Cooling Plate

2018 ◽  
Vol 7 (4.26) ◽  
pp. 170 ◽  
Author(s):  
Irnie Azlin Zakaria ◽  
Wan Ahmad Najmi Wan Mohamed ◽  
Wan Azmi Wan Hamzah
Keyword(s):  
Heat Transfer ◽  
Fluid Flow ◽  
Proton Exchange Membrane ◽  
Combustion Engine ◽  
Flow Behavior ◽  
Constant Heat Flux ◽  
Proton Exchange ◽  
Cooling Plate ◽  
Excessive Heat ◽  
Actual Application

Proton exchange membrane fuel cell (PEMFC) is among the potential substitute to current conventional internal combustion engine (ICE) in the automotive sector due to its efficient conversion efficiency and environmental friendly. However, thermal management issues in PEMFC needs to be addressed as excessive heat in PEMFC can deteriorate its performance as well as causing dehydration to the membrane. In this study, an advanced coolant of SiO2 nanofluids was numerically studied and effect in term of the heat transfer and fluid flow behavior in a single PEMFC cooling plate is investigated.  The study simulated SiO2 nanofluids in a serpentine PEMFC cooling plate. The simulation is conducted at a low volume concentrations of 0.1, 0.3 and 0.5 % of SiO2 in water and water: Ethylene Glycol (W:EG) of 60:40 as base fluids. In this serpentine cooling plate design of PEMFC, a constant heat flux is applied to mimic the actual application of PEMFC. Upon completion of the study, heat transfer and fluid flow shows that the heat transfer coefficient of 0.5 vol. % of SiO2 nanofluids has improved by 3.5 % at Reynold (Re) number of 400 as compared to the base fluid of water with an acceptable pumping power increment.  

Numerical Simulations of Fluid Flow and Heat Transfer in Pulse Tubes

2005 ◽  
pp. 303-312
Author(s):  
A. E. Schroth ◽  
M. Sahimi ◽  
C. S. Kirkconnell
Keyword(s):  
Heat Transfer ◽  
Fluid Flow ◽  
Numerical Simulations ◽  
Flow And Heat Transfer
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