Natural Convective Characteristics of an Oblique Heat Source Module in the Closed and Ventilated Cabinets

2010 ◽  
Author(s):  
Yeong-Ley Tsay ◽  
Jen-Chieh Cheng ◽  
Yong-Lin Zhuang
Keyword(s):  
Heat Source ◽  
Hot Spot ◽  
Velocity Fields ◽  
Thermal Interaction ◽  
Surrounding Area ◽  
The Difference ◽  
Conjugate Conduction ◽  
Temperature And Velocity Fields ◽  
Air Streams ◽  
Spot Temperature

A numerical analysis is performed to study the characteristics of heat transfer from a block heat source module at different angles in two-dimensional cabinets. Great efforts are carried out to conduct the effects of thermal interaction between the air steams inside and outside the cabinet on the conjugate conduction–natural convection phenomena. Moreover, the enhancement of cooling performance of the heat source module through the construction of air vents on cabinet wall is rigorously examined. The computation domain covers the cabinet and the surrounding area, and the temperature and velocity fields of the cabinet and surrounding area are solved simultaneously. Results show that the thermal interaction between the airs inside and outside the cabinet, the module angle and vent position can significantly affect the transfer characteristics. Comparing the results for cases with and without the consideration of thermal interaction between the air streams, the difference in hot spot temperature of module can be up to 26% for Pr = 0.7, Kbf = Kpf = Kwf = 100, 105 ≦ Ra ≦ 107 and φ = 0°, 90°, 270°. The maximum reduction in hot spot temperature is about 41% when two air vents are constructed on cabinet wall. The variation of module angle results in the maximum difference of the hot spot temperature is 15% for closed cabinet, and 10% for ventilated cabinet.

Characteristics of Heat Dissipation from a Block Heat Source Module in a Three-Dimensional Cabinet to Ambient Natural Convective Air Stream

2012 ◽  
Vol 229-231 ◽  
pp. 2589-2592
Author(s):  
Y.L. Tsay ◽  
J.C. Cheng
Keyword(s):  
Natural Convection ◽  
Rayleigh Number ◽  
Heat Source ◽  
Heat Dissipation ◽  
Three Dimensional ◽  
Thermal Interaction ◽  
Air Stream ◽  
Conjugate Conduction ◽  
Air Streams ◽  
Thermal Conductivities

This study combined the numerical analysis and experimental measurement to investigate the conjugate conduction and natural convection for a block heat source module in a three-dimensional cabinet filled and surrounded by air. The effects of Rayleigh number Ra, module position C1, ratio of block to air thermal conductivities Kbf, and ratio of board to air thermal conductivities Kpf are examined. Moreover, efforts are carried out to explore the influence of thermal interaction between the air streams inside and outside the cabinet.

Free Convection Thermal Interaction Between 2D Components Mounted on a Vertically Oriented PCB

2002 ◽  
Author(s):  
D. Newport ◽  
T. Dalton ◽  
M. Davies
Keyword(s):  
Boundary Layer ◽  
Effective Conductivity ◽  
Ball Grid Array ◽  
Velocity Fields ◽  
Two Dimensional ◽  
Thermal Interaction ◽  
Trade Off ◽  
Layer Flow ◽  
Digital Moiré ◽  
Temperature And Velocity Fields

In this paper, measurements are presented of the temperature and velocity fields about two PCBs, with an array of five equally spaced two dimensional ribs. The ribs are two dimensional approximations of the Super Ball Grid Array (SuperBGA) package from Amkor electronics. The temperature and Nusselt number distributions are measured using Digital Moire´ Subtraction Interferometry and PIV is used to measure the velocity field. The effect of substrate conductivity is examined, and the level of thermal interaction is quantified. It is found that substrate conductivity significantly alters the induced boundary layer flow and also the recirculating vortex structure external to it. It is also found that there is a trade-off between a downstream component being heated by the thermal energy of the plume from a lower component, and cooled by the kinetic energy of that plume. The spacing to length ratio, above which the cooling effect is greater, is three for components mounted on a board with a high effective conductivity (15 W/m K). The ratio is greater than three for PCBs with lower effective conductivities. Previous work in the literature indicates a ratio greater than four for components mounted flush with an adiabatic substrate.

scholarly journals Influence of thermo-gravitational convection to temperature fields in small surroundings of the heat source

2018 ◽  
Vol 194 ◽  
pp. 01028
Author(s):  
Alexander Kondakov
Keyword(s):  
Mathematical Modeling ◽  
Heat Transfer ◽  
Temperature Field ◽  
Heat Source ◽  
Velocity Fields ◽  
Temperature Fields ◽  
Conductive Heat ◽  
Gravitational Convection ◽  
Temperature And Velocity Fields ◽  
The Impact

The mathematical modeling of temperature and velocity fields in the system “the heat source - environment - the object of heating” was conducted. The impact assessment of thermo-gravitational convection to the temperature field in comparison with the model of conductive heat transfer was done.

scholarly journals Heat Transfer Analysis for Viscous Fluid Flow with the Newtonian Heating and Effect of Magnetic Force in a Rotating Regime

Complexity ◽  
2021 ◽  
Vol 2021 ◽  
pp. 1-11
Author(s):  
Rashid Ayub ◽  
Shahzad Ahmad ◽  
Muhammad Imran Asjad ◽  
Mushtaq Ahmad
Keyword(s):  
Viscous Fluid ◽  
Fluid Motion ◽  
Velocity Fields ◽  
Heat Transfer Analysis ◽  
Convection Flow ◽  
Newtonian Heating ◽  
Flow Parameters ◽  
Laplace Transform Technique ◽  
The Laplace Transform ◽  
Temperature And Velocity Fields

In this article, an unsteady free convection flow of MHD viscous fluid over a vertical rotating plate with Newtonian heating and heat generation is analyzed. The dimensionless governing equations for temperature and velocity fields are solved using the Laplace transform technique. Analytical solutions are obtained for the temperature and components of velocity fields. The obtained solutions satisfy the initial and boundary conditions. Some physical aspects of flow parameters on the fluid motion are presented graphically.

scholarly journals Pendugaan Kejadian Pemutihan Karang Berdasarkan Analisis Suhu Permukaan Laut (SPL) Tahun 2015-2016 di Perairan Bali

2017 ◽  
Vol 4 (2) ◽  
pp. 286
Author(s):  
Jajang Nuryana ◽  
I Gede Hendrawan ◽  
Widiastuti Karim
Keyword(s):  
Coral Bleaching ◽  
Hot Spot ◽  
Satellite Image ◽  
Distribution Patterns ◽  
Triangle Center ◽  
Moderate Resolution ◽  
Resolution Imaging ◽  
Moderate Resolution Imaging Spectroradiometer ◽  
The Difference ◽  
Level 2

National Ocean Atmospheric Administrations (NOAA) by the program coral reef Watch (CRW) has developed a method to estimate the potential of coral bleaching using Sea Surface Temperature (SST). The products are hot spot (HS) and degree heating week (DHW). HS is the SST 1°C (SSTL?1) above normal and DHW is the length of HS inhabits a place. The CRW product do not provided detail informations because it has a lower resolution. It is need a satellite image with a higher resolution to provide better informations. One of the satellite images that can be used is Moderate Resolution Imaging Spectroradiometer (MODIS) with a spatial resolution of 1 km. The purpose of this study was to know HS and DHW distribution patterns and status of coral bleaching in Bali waters seen from the analysis of HS and DHW. MODIS data is used daily, then do mosaicing process to get a weekly SPL (8 daily) and the monthly SST. Monthly SPL normally used to get maximum montly mean (MMM). HS obtained from the difference between 8 daily weekly SST and SST normal (MMM).).Location bleaching based on data Coral Triangle Center (CTC) and coralwatch.org.  SST results revealed difference of SPL in 2015 and 2016 amounted to 1.48°C. Highest DHW in Bali Hai, Nusa Penida is 10 465° C-weeks in April 2016. Based on the value HS and DHW coral reefs in Bali waters threatened bleaching level Alert 1 and Alert level 2.

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