scholarly journals Calculation Method for Forced-Air Convection Cooling Heat Transfer Coefficient of Multiple Rows of Memory Cards

2014 ◽  
Vol 04 (03) ◽  
pp. 70-77 ◽  
Author(s):  
Takayuki Atarashi ◽  
Tetsuya Tanaka ◽  
Shigeyasu Tsubaki ◽  
Shigeki Hirasawa
Keyword(s):  
Heat Transfer ◽  
Heat Transfer Coefficient ◽  
Transfer Coefficient ◽  
Calculation Method ◽  
Air Convection ◽  
Convection Cooling ◽  
Forced Air

Average Wall Radiative Heat Transfer Characteristic of Isothermal Radiative Medium in Inner Straight Fin Tubes

2021 ◽  
Author(s):  
Wenping Peng ◽  
Min Xu ◽  
Xiaoxia Ma ◽  
Xiulan Huai
Keyword(s):  
Heat Transfer ◽  
Heat Transfer Coefficient ◽  
Transfer Coefficient ◽  
Radiative Heat Transfer ◽  
Calculation Method ◽  
Radiative Heat ◽  
Solid Surfaces ◽  
Design Calculation ◽  
Radiative Heat Transfer Coefficient ◽  
Fin Tubes

Abstract Wall radiative heat transfer in inner straight fin tubes is very complex considering the coupling of heat conduction in fins and radiative heat transfer of medium with solid surfaces, influenced by a number of factors such as fin parameters, radiative pro perties and run conditions. In this study, a simplified method is used.The average radiative heat transfer between radiative medium and solid surfaces is firstly studied by simulation with fins assumed having a constant temperature. Then an approximate correlation of this radiative heat transfer coefficient is proposed using the traditional radiative heat transfer calculation method with a view coefficient, having a error within 15%. A calculation method of average wall radiative heat transfer coefficient is further proposed by fin theory with an average temperature of fin surface used to consider the varying of the temperature along the fin when the conductivity of fins is finite. Using the predicting method proposed, a method for design calculation of fins in tubes to optimize wall radiative heat transfer is also given with three dimensionless numbers of p/n, 2H/D and nt/pD defined. Three cases of are analyzed in detail based on the design calculation method. It is verified that the radiative heat transfer could be enhanced twice by introducing fins. Under the same h0, conductivity and emissivity are two important factors to choose the material for fins.The micro-fins or the special treatments on the tube wall are a best choice for the fin material having a relatively small conductivity.

Heat transfer between Phaseolus vulgaris and the environment

1971 ◽  
Vol 49 (6) ◽  
pp. 833-838 ◽  
Author(s):  
T. F. Saldin ◽  
N. Barthakur
Keyword(s):  
Heat Transfer ◽  
Heat Transfer Coefficient ◽  
Phaseolus Vulgaris ◽  
Transfer Coefficient ◽  
Convective Heat Transfer ◽  
Convective Heat ◽  
Convective Heat Transfer Coefficient ◽  
Forced Air ◽  
Theoretical Results ◽  
Infrared Radiometer

Heat transfer was studied from intact leaves of greenhouse-grown Phaseolus vulgaris L. under still and forced air conditions. Microwaves were used to heat the leaves without disturbing the thermal equilibrium of the environment. Leaf temperatures were measured by thermocouples and an infrared radiometer. Convective heat transfer coefficient for a leaf was obtained by two experimental methods and compared with the theoretical results. The unsteady-state method proved to be quite satisfactory.Typical values of heat transfer coefficient for free convection varied from 1.86 × 10−4 to 3.64 × 10−4 cal cm−2 s−1 °C−1, as the temperature difference between the leaf surface and the surrounding air increased from 1.0 to 3.9 °C. Forced convective heat transfer coefficient, however, increased to about 10 × 10−4 cal cm−2 s−1 °C−1 at 610 cm s−1.

Board-Side Boundary Condition for a Single Component on a PCB in Forced Convection

2002 ◽  
Author(s):  
Sriram Neelakantan ◽  
Victor Adrian Chiriac
Keyword(s):  
Heat Transfer ◽  
Boundary Condition ◽  
Heat Transfer Coefficient ◽  
Transfer Coefficient ◽  
Forced Convection ◽  
Integrated Circuit ◽  
Calculation Method ◽  
Cfd Simulation ◽  
Analytical Calculation ◽  
Junction Temperature

Computational Fluid Dynamics (CFD) tools are routinely used to get accurate predictions of junction temperatures of Integrated Circuit (IC) packages. However, it is desirable to obtain reasonably accurate junction temperature estimates as early as possible in the design process without having to model the board and flow in large detail. In order to accomplish this, a good estimate of the board side thermal resistance is required. The new method presented here estimates the board side resistance for a standard JEDEC high conductivity board in forced convection. The overall board resistance incorporates the spreading resistance of the board, taking into account the multiple layers of copper and dielectric, also the heat transfer coefficient from the board using established correlations. The results of the calculation method are further compared with a full CFD simulation of a simplified package on a board. Good agreement is obtained between the CFD simulation and the proposed method in predicting the junction and case temperatures. The numerical discrepancies are within 1.5% and 4.2% respectively, over a broad range of airflow speeds typical of forced convection cooled electronics systems. The accuracy of the proposed analytical calculation method recommends it as a potential method of replacement of a full CFD simulation of the board and component with a conduction only analysis. The board-side boundary condition for this analysis could be represented with an equivalent heat transfer coefficient.

scholarly journals Considerations on the importance of proper heat transfer coefficient modeling in air cooled electronic systems

2018 ◽  
Vol 31 (4) ◽  
pp. 519-528 ◽  
Author(s):  
Marcin Janicki ◽  
Agnieszka Samson ◽  
Tomasz Raszkowski ◽  
Tomasz Torzewicz ◽  
Andrzej Napieralski
Keyword(s):  
Heat Transfer ◽  
Heat Transfer Coefficient ◽  
Heat Source ◽  
Transfer Coefficient ◽  
Local Heat Transfer ◽  
Local Heat ◽  
Electronic Systems ◽  
Air Cooling ◽  
Simulation Accuracy ◽  
Forced Air

This paper illustrates, based on a practical example of a hybrid circuit, the influence of proper heat transfer coefficient modelling in air cooled electronic systems on the accuracy of thermal simulations. This circuit contains a transistor heat source and a set of temperature sensors. The measurements of their temperature responses are taken in natural convection and forced air cooling conditions. The experimental data provide the information necessary to estimate the local heat transfer coefficient values in heat source and temperature sensor locations. Moreover, the experiments rendered possible the fitting of parameters of an empirical heat transfer coefficient model for different surface temperature rise values and cooling air velocities, and hence allowed significant improvement of thermal simulation accuracy.

Sign in / Sign up

Export Citation Format

Share Document