An Experimental Assessment of Numerical Predictive Accuracy for Electronic Component Heat Transfer in Forced Convection—Part I: Experimental Methods and Numerical Modeling

2003 ◽  
Vol 125 (1) ◽  
pp. 67-75 ◽  
Author(s):  
Peter J. Rodgers ◽  
Vale´rie C. Eveloy ◽  
Mark R. D. Davies

Numerical predictive accuracy is assessed for component-printed circuit board (PCB) heat transfer in forced convection using a computational fluid dynamics (CFD) software for the thermal analysis of electronic equipment. This is achieved by comparing numerical predictions with experimental benchmark data for three different components, mounted individually on single-component PCBs, and collectively on a multi-component PCB. Benchmark criteria are based on measured steady-state component junction temperature and component-PCB surface temperature profiles. The benchmark strategy applied permits the impact of both aerodynamic conditions and component thermal interaction on predictive accuracy to be quantified. In the accompanying Part II of this paper, the experimental measurements are reported and numerical predictive accuracy is assessed.

2003 ◽  
Vol 125 (1) ◽  
pp. 76-83 ◽  
Author(s):  
Peter J. Rodgers ◽  
Vale´rie C. Eveloy ◽  
Mark R. Davies

Numerical predictive accuracy is assessed for component-printed circuit board (PCB) heat transfer in forced convection using a widely used computational fluid dynamics (CFD) software. In Part I of this paper, the benchmark test cases, experimental methods and numerical models were described. Component junction temperature prediction accuracy for the populated board case is typically within ±5°C or ±10%, which would not be sufficient for temperature predictions to be used as boundary conditions for subsequent reliability and electrical performance analyses. Neither the laminar or turbulent flow model resolve the complete flow field, suggesting the need for a turbulence model capable of modeling transition. The full complexity of component thermal interaction is shown not to be fully captured.


2004 ◽  
Vol 127 (3) ◽  
pp. 245-254 ◽  
Author(s):  
Valérie Eveloy ◽  
Peter Rodgers ◽  
M. S. J. Hashmi

Numerical predictive accuracy is assessed for board-mounted electronic component heat transfer in free convection, using a computational fluid dynamics code dedicated to the thermal analysis of electronic equipment. This is achieved by comparing numerical predictions with experimental measurements of component junction temperature and component-PCB surface temperature, measured using thermal test chips and infrared thermography, respectively. The printed circuit board (PCB) test vehicle considered is populated with fifteen 160-lead PQFP components generating a high degree of component thermal interaction. Component numerical modeling is based on vendor-specified, nominal package dimensions and material thermophysical properties. To permit both the modeling methodology applied and solver capability to be carefully evaluated, test case complexity is incremented in controlled steps, from individually to simultaneously powered component configurations. Component junction temperature is predicted overall to within ±5°C (7%) of measurement, independently of component location on the board. However, component thermal interaction is found not to be fully captured.


Author(s):  
Ramin K. Rahmani ◽  
Emad Y. Tanbour ◽  
Anahita Ayasoufi ◽  
Hosein Molavi

Enhancement of the natural and forced convection heat transfer has been the subject of numerous academic and industrial studies. Air blenders, mechanical agitators, and static mixers have been developed to increase the forced convection heat transfer rate in compressible and incompressible flows. Stationary inserts can be efficiently employed as heat transfer enhancement devices in natural and mixed convection systems with compressible flow. These devices have low maintenance and operating costs, low space requirements, and no moving parts. Through numerical studies, this paper demonstrates how an insert improves heat transfer in buoyancy driven flow. The numerical predictions are validated using experimental data. Using different measurement tools, the global performance of the insert and the impact of the geometrical parameters are studied, leading to identification of the most effective design for a given application.


Energies ◽  
2021 ◽  
Vol 14 (5) ◽  
pp. 1286
Author(s):  
Krzysztof Górecki ◽  
Przemysław Ptak

This paper concerns the problem of modelling electrical, thermal and optical properties of multi-colour power light-emitting diodes (LEDs) situated on a common PCB (Printed Circuit Board). A new form of electro-thermo-optical model of such power LEDs is proposed in the form of a subcircuit for SPICE (Simulation Program with Integrated Circuits Emphasis). With the use of this model, the currents and voltages of the considered devices, their junction temperature and selected radiometric parameters can be calculated, taking into account self-heating phenomena in each LED and mutual thermal couplings between each pair of the considered devices. The form of the formulated model is described, and a manner of parameter estimation is also proposed. The correctness and usefulness of the proposed model are verified experimentally for six power LEDs emitting light of different colours and mounted on an experimental PCB prepared by the producer of the investigated devices. Verification was performed for the investigated diodes operating alone and together. Good agreement between the results of measurements and computations was obtained. It was also proved that the main thermal and optical parameters of the investigated LEDs depend on a dominant wavelength of the emitted light.


2009 ◽  
Vol 419-420 ◽  
pp. 37-40
Author(s):  
Shiuh Chuan Her ◽  
Shien Chin Lan ◽  
Chun Yen Liu ◽  
Bo Ren Yao

Drop test is one of the common methods for determining the reliability of electronic products under actual transportation conditions. The aim of this study is to develop a reliable drop impact simulation technique. The test specimen of a printed circuit board is clamped at two edges on a test fixture and mounted on the drop test machine platform. The drop table is raised at the height of 50mm and dropped with free fall to impinge four half-spheres of Teflon. One accelerometer is mounted on the center of the specimen to measure the impact pulse. The commercial finite element software ANSYS/LS-DYNA is applied to compute the impact acceleration and dynamic strain on the test specimen during the drop impact. The finite element results are compared to the experimental measurement of acceleration with good correlation between simulation and drop testing. With the accurate simulation technique, one is capable of predicting the impact response and characterizing the failure mode prior to real reliability test.


Author(s):  
Mandana S. Saravani ◽  
Saman Beyhaghi ◽  
Ryoichi S. Amano

The present work investigates the effects of buoyancy and density ratio on the thermal performance of a rotating two-pass square channel. The U-bend configuration with smooth walls is selected for this study. The channel has a square cross-section with a hydraulic diameter of 5.08 cm (2 inches). The lengths of the first and second passes are 514 mm and 460 mm, respectively. The turbulent flow enters the channel with Reynolds numbers of up to 34,000. The rotational speed varies from 0 to 600 rpm with the rotational numbers up to 0.75. For this study, two approaches are considered for tracking the buoyancy effect on heat transfer. In the first case, the density ratio is set constant, and the rotational speed is varied. In the second case, the density ratio is changed in the stationary case, and the effect of density ratio is discussed. The range of Buoyancy number along the channel is 0–6. The objective is to investigate the impact of Buoyancy forces on a broader range of rotation number (0–0.75) and Buoyancy number scales (0–6), and their combined effects on heat transfer coefficient for a channel with aspect ratio of 1:1. Several computational fluid dynamics (CFD) simulation are carried out for this study, and some of the results are validated against experimental data.


2013 ◽  
Vol 795 ◽  
pp. 603-610 ◽  
Author(s):  
Mohamed Mazlan ◽  
A. Rahim ◽  
M.A. Iqbal ◽  
Mohd Mustafa Al Bakri Abdullah ◽  
W. Razak ◽  
...  

Plastic Leaded Chip Carrier (PLCC) package has been emerged a promising option to tackle the thermal management issue of micro-electronic devices. In the present study, three dimensional numerical analysis of heat and fluid flow through PLCC packages oriented in-line and mounted horizontally on a printed circuit board, is carried out using a commercial CFD code, FLUENTTM. The simulation is performed for 12 PLCC under different inlet velocities and chip powers. The contours of average junction temperatures are obtained for each package under different conditions. It is observed that the junction temperature of the packages decreases with increase in inlet velocity and increases with chip power. Moreover, the increase in package density significantly contributed to rise in temperature of chips. Thus the present simulation demonstrates that the chip density (the number of packages mounted on a given area), chip power and the coolant inlet velocity are strongly interconnected; hence their appropriate choice would be crucial.


2021 ◽  
Author(s):  
Sanaz Dianat

The research paper investigates the impact of a window’s exterior air film on the assembly temperature. The exterior air film constitutes a vital portion of a window’s insulating values. The air film increases the temperature of the window exterior pane to a temperature above ambient temperature. The air film also rises the interior glass temperature and reduces the heat transfer from the interior surface. According to computational fluid dynamics (CFD), the air film is removed in windy conditions, decreasing the window temperature on the outside as well as on the inside. The idea behind the project is to carry out an experimental procedure on three different windows to validate the CFD results, which indicates the effect of various wind speeds. Keyword: Exterior air film, computational fluid dynamics, window assembly, wind speed


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