Effect of V cut in perforated twisted tape insert on heat transfer and fluid flow behavior of tube flow: An experimental study

2018 ◽  
Vol 32 (6) ◽  
pp. 524-544 ◽  
Author(s):  
Bipin Kumar ◽  
Manoj Kumar ◽  
Anil Kumar Patil ◽  
Siddharth Jain
Keyword(s):  
Heat Transfer ◽  
Experimental Study ◽  
Fluid Flow ◽  
Flow Behavior ◽  
Twisted Tape ◽  
Tube Flow

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 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.

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