Sensitivity Analysis of Schlieren-PIV System for Simultaneous Measurement of Flow and Temperature Field of a Free Convective Flow inside a Cubic Cavity

2021 ◽  
pp. 1-38
Author(s):  
Omprakash S. Bharti ◽  
Arun Saha ◽  
Malay Das
Keyword(s):  
Nusselt Number ◽  
Temperature Field ◽  
Convective Flow ◽  
Dynamic Range ◽  
Three Dimensional ◽  
Interrogation Window ◽  
Window Size ◽  
Knife Edge ◽  
Time Separation ◽  
Interrogation Window Size

Abstract Fluid flows characterized by density variations have been studied using the schlieren-PIV system. The knife-edge location plays a crucial role in determining the system's sensitivity, which significantly affects the accuracy of the measured quantities. Further, the optimum knife-edge position and the correct combination of image recording speed and interrogation window size is desirable for achieving the most accurate and reliable results. The present paper discusses the above issues on the measured quantities, such as temperature field, local Nusselt number distribution along the conducting walls, average Nusselt number, and velocity field. The experiment is performed to investigate laminar and steady natural convective flow in a water-enclosed cubic cavity with left hot and right cold walls. The analysis is undertaken for various knife-edge position (0-90%), different image time separation varying (20-200 ms) and interrogation window size using two passes varying from W1 = 32 pixels, W2 = 16 pixels to W1 = 128 pixels, W2 = 64 pixels. The results are presented for two distinct Rayleigh number, 1 × 108 and 3 × 108. Three-dimensional simulations have been carried out to check the fidelity of the experiment for Ra = 1 × 108. A high dynamic range of temperature is obtained for the range of knife-edge position in 50-65% while a high velocity range is realized for knife-edge cut-off of 65% and combination of image time separation of Δt = 100 ms and interrogation window size with two passes of W1 = 64 pixels followed by W2 = 32 pixels.

scholarly journals Effect of constant suction and injection on MHD three dimensional couette flow and heat transfer through a porous medium

2010 ◽  
Vol 6 (1) ◽  
pp. 41-51 ◽  
Author(s):  
S. S. Das
Keyword(s):  
Heat Transfer ◽  
Porous Medium ◽  
Nusselt Number ◽  
Temperature Field ◽  
Skin Friction ◽  
Couette Flow ◽  
Three Dimensional ◽  
Injection Parameter ◽  
Constant Suction ◽  
Permeability Parameter

The objective of this paper is to analyzethe effect of constant suction and sinusoidal injection on three dimensional couette flow of a viscous incompressible electrically conducting fluid through a porous medium between two infinite horizontal parallel porous flat plates in presence of a transverse magnetic field. The stationary plate and the plate in uniform motion are, respectively, subjected to a transverse sinusoidal injection and uniform suction of the fluid .The flow becomes three dimensional due to this type of injection velocity distribution. The governing equations of the flow field are solved by using series expansion method and the expressions for the velocity field, the temperature field, skin friction and the rate of heat transfer in terms of Nusselt number are obtained. The effects of the flow parameters on the velocity field, temperature field, skin friction and the Nusselt number have been studied and analyzed with the help of figures and tables. It is observed that a growing magnetic parameter (M) retards the main velocity (u) and accelerates the cross flow velocity (w1) of the flow field and a growing permeability parameter (Kp) or suction / injection parameter (Re) reverses the effect. Both Prandtl number (Pr) and the suction / injection parameter have retarding effect on the temperature field. Further, a growing suction / injection parameter diminishes both the components of skin friction at the wall while the permeability parameter enhances the x-component and reduces the z-component of the skin friction at the wall. The effect of increasing permeability parameter is to enhance the magnitude of rate of heat transfer at the wall while a growing Prandtl number (Pr) reverses the effect.Keywords: MHD; couette flow; heat transfer; suction; sinusoidal injection; porous mediumDOI: 10.3329/jname.v5i2.2570Journal of Naval Architecture and Marine Engineering 6(1)(2009) 41-51 

Magneto convective flow of casson nanofluid due to Stefan blowing in the presence of bio-active mixers

2021 ◽  
pp. 239779142110166
Author(s):  
Venkatesh Puneeth ◽  
Sarpabhushana Manjunatha ◽  
Bijjanal Jayanna Gireesha ◽  
Rama Subba Reddy Gorla
Keyword(s):  
Magnetic Field ◽  
Brownian Motion ◽  
Convective Flow ◽  
Three Dimensional ◽  
Induced Magnetic Field ◽  
Density Profiles ◽  
Casson Nanofluid ◽  
And Brownian Motion ◽  
Similarity Transformations ◽  
The Mathematical Model

The induced magnetic field for three-dimensional bio-convective flow of Casson nanofluid containing gyrotactic microorganisms along a vertical stretching sheet is investigated. The movement of these microorganisms cause bioconvection and they act as bio-active mixers that help in stabilising the nanoparticles in the suspension. The two forces, Thermophoresis and Brownian motion are incorporated in the Mathematical model along with Stefan blowing. The resulting model is transformed to ordinary differential equations using similarity transformations and are solved using [Formula: see text] method. The Velocity, Induced Magnetic field, Temperature, Concentration of Nanoparticles, and Motile density profiles are interpreted graphically. It is observed that the Casson parameter decreases the flow velocity and enhances the temperature, concentration, and motile density profiles and also it is noticed that the blowing enhances the nanofluid profiles whereas, suction diminishes the nanofluid profiles. On the other hand, it is perceived that the rate of heat conduction is enhanced with Thermophoresis and Brownian motion.

scholarly journals Study of Mini Channel Heat Sink with Different Internal Configuration

2020 ◽  
Vol 319 ◽  
pp. 02004
Author(s):  
Muhammad Akif Rahman ◽  
Md Badrath Tamam ◽  
Md Sadman Faruque ◽  
A.K.M. Monjur Morshed
Keyword(s):  
Nusselt Number ◽  
Thermal Performance ◽  
Heat Sink ◽  
Rectangular Channel ◽  
Three Dimensional ◽  
Heat Sinks ◽  
Maximum Temperature ◽  
Rectangular Channels ◽  
Flow Through ◽  
Internal Configuration

In this paper a numerical analysis of three-dimensional laminar flow through rectangular channel heat sinks of different geometric configuration is presented and a comparison of thermal performance among the heat sinks is discussed. Liquid water was used as coolant in the aluminum made heat sink with a glass cover above it. The aspect ratio (section height to width) of rectangular channels of the mini-channel heat sink was 0.33. A heat flux of 20 W/cm2 was continuously applied at the bottom of the channel with different inlet velocity for Reynold’s number ranging from 150 to 1044. Interconnectors and obstacles at different positions and numbers inside the channel were introduced in order to enhance the thermal performance. These modifications cause secondary flow between the parallel channels and the obstacles disrupt the boundary layer formation of the flow inside the channel which leads to the increase in heat transfer rate. Finally, Nusselt number, overall thermal resistance and maximum temperature of the heat sink were calculated to compare the performances of the modified heat sinks with the conventional mini channel heat sink and it was observed that the heat sink with both interconnectors and obstacles enhanced the thermal performance more significantly than other configurations. A maximum of 36% increase in Nusselt number was observed (for Re =1044).

Foundations of Advanced Neuroanatomy: Technical Guidelines for Specimen Preparation, Dissection, and 3D-Photodocumentation in a Surgical Anatomy Laboratory

2019 ◽  
Author(s):  
Luciano César PC Leonel ◽  
Lucas P. Carlstrom ◽  
Christopher S. Graffeo ◽  
Avital Perry ◽  
Carlos Diogenes Pinheiro-Neto ◽  
...  
Keyword(s):  
Oral Tradition ◽  
Dynamic Range ◽  
Tap Water ◽  
Three Dimensional ◽  
High Dynamic Range ◽  
Surgical Anatomy ◽  
Lessons Learned ◽  
Specimen Preparation ◽  
Technological Advances ◽  
Key Steps

Abstract Objective This study was aimed to provide a key update to the seminal works of Prof. Albert L. Rhoton Jr., MD, with particular attention to previously unpublished insights from the oral tradition of his fellows, recent technological advances including endoscopy, and high-dynamic range (HDR) photodocumentation, and, local improvements in technique, we have developed to optimize efficient neuroanatomic study. Methods Two formaldehyde-fixed cadaveric heads were injected with colored latex to demonstrate step-by-step specimen preparation for microscopic or endoscopic dissection. One formaldehyde-fixed brain was utilized to demonstrate optimal three-dimensional (3D) photodocumentation techniques. Results Key steps of specimen preparation include vessel cannulation and securing, serial tap water flushing, specimen drainage, vessel injection with optimized and color-augmented latex material, and storage in 70% ethanol. Optimizations for photodocumentation included the incorporation of dry black drop cloth and covering materials, an imaging-oriented approach to specimen positioning and illumination, and single-camera stereoscopic capture techniques, emphasizing the three-exposure-times-per-eye approach to generating images for HDR postprocessing. Recommended tools, materials, and technical nuances were emphasized throughout. Relative advantages and limitations of major 3D projection systems were comparatively assessed, with sensitivity to audience size and purpose specific recommendations. Conclusion We describe the first consolidated step-by-step approach to advanced neuroanatomy, including specimen preparation, dissection, and 3D photodocumentation, supplemented by previously unpublished insights from the Rhoton fellowship experience and lessons learned in our laboratories in the past years such that Prof. Rhoton's model can be realized, reproduced, and expanded upon in surgical neuroanatomy laboratories worldwide.

scholarly journals Ab initiostructure determination of nanocrystals of organic pharmaceutical compounds by electron diffraction at room temperature using a Timepix quantum area direct electron detector

2016 ◽  
Vol 72 (2) ◽  
pp. 236-242 ◽  
Author(s):  
E. van Genderen ◽  
M. T. B. Clabbers ◽  
P. P. Das ◽  
A. Stewart ◽  
I. Nederlof ◽  
...  
Keyword(s):  
Electron Diffraction ◽  
Room Temperature ◽  
Dynamic Range ◽  
Signal To Noise Ratio ◽  
Three Dimensional ◽  
Direct Methods ◽  
Liquid Nitrogen Temperature ◽  
High Dynamic Range ◽  
Electron Diffraction Data ◽  
High Signal

Until recently, structure determination by transmission electron microscopy of beam-sensitive three-dimensional nanocrystals required electron diffraction tomography data collection at liquid-nitrogen temperature, in order to reduce radiation damage. Here it is shown that the novel Timepix detector combines a high dynamic range with a very high signal-to-noise ratio and single-electron sensitivity, enablingab initiophasing of beam-sensitive organic compounds. Low-dose electron diffraction data (∼0.013 e− Å−2 s−1) were collected at room temperature with the rotation method. It was ascertained that the data were of sufficient quality for structure solution using direct methods using software developed for X-ray crystallography (XDS,SHELX) and for electron crystallography (ADT3D/PETS,SIR2014).

scholarly journals The study of three-dimensional temperature field distribution reconstruction using ultrasonic thermometry

AIP Advances ◽  
2016 ◽  
Vol 6 (7) ◽  
pp. 075007 ◽  
Author(s):  
Ruixi Jia ◽  
Qingyu Xiong ◽  
Kai Wang ◽  
Lijie Wang ◽  
Guangyu Xu ◽  
...  
Keyword(s):  
Temperature Field ◽  
Field Distribution ◽  
Three Dimensional ◽  
Temperature Field Distribution
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