Figure 1. AFT description Fin pitch = 25.01 per in = 985 per mPlate spacing, b = 0.200 in = 5.08 x 10-3 m Fin Length = 0.111 in = 2.8 x 10-3 m Flow passage hydraulic diameter 4rh = 0.004905 ft = 1.50 x 10-3 m Fin metal thickness = 0.004 in = 0.102 x 10-3 m Total heat transfer area/volume between plates, ß = 719.4 ft2 / ft3 = 2,360 m2 / m3 Fin area / total area = … [Read more...]
All you need to know about fans
A Basic Fan/Blower Description Fans can be thought of as low pressure air pumps that utilize power from amotor to output a volumetric flow of air at a given pressure. A propellerconverts torque from the motor to increase static pressure across the fan rotorand to increase the kinetic energy of the air particles. The motors aretypically permanent split capacitor AC induction … [Read more...]
How to evaluate fan life
Convection air cooling is still the most commonly used method of coolingmicroelectronics. In order to deliver air cooled computer equipment with higherreliability, we need to focus on the life expectancy of the air moving devices(AMDs). However, this is not a trivial exercise because there are so manyvariables and there is no industry standard for AMD life test procedures. … [Read more...]
Minimizing acoustical noise in electronic systems
Introduction Air-moving devices (AMDs), such as fans and blowers used for cooling inelectronic systems invariably generate acoustical noise which must be consideredif people are exposed to the emitted noise. In this article, we discussquantitative measures for the description of noise, design guidelines for theselection of low noise air movers, upper limits for the noise … [Read more...]
Fan cooled enclosure analysis using a first order method
Introduction Most Electronics Packaging Engineers and Analysis Specialists have access toa wide range of high quality analysis tools. While a few computer programs useanalytical methods, the majority are based on numerical analysis techniques.Although these programs are becoming easier to use, they typically requireconsiderable skill, and they are certainly capable of producing … [Read more...]
