The simplest heat flow situation is that described as “one-dimensional heat flow”. The Figure illustrates a one-dimensional heat flow situation. It shows heat flowing in one face of an object and out the opposite face. Each face is at a uniform temperature. There is no heat flow out of the sides of the object. The cross- sectional area of the object in the direction of heat … [Read more...]
Standardizing heat sink characterization for forced convection
Figure 1. Wind tunnel configuration Introduction While there has been a flurry of activity inliterature addressing the behavior of heat sinks in computer electronics,the reusability of the data presented in these papers has been somewhatlimited for two reasons: 1) The data presented is application specific. 2) There has never been a standard method for characterizing … [Read more...]
Forced convection cooling of airborne electronics
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...]
Thermal Conductivity
For most calculations regarding the thermal analysis of electronic systems, thermal conductivities of solid materials are required. It is felt that many designers would welcome a comprehensive list showing these values for certain classes of objects, such as PCB materials, leadframes, molding compounds, alloys etc.. This issue starts with 45 leadframe materials, the data for … [Read more...]
A simple method to estimate heat sink air flow bypass
Introduction After selecting or designing a heat sink based upon a given air velocity orvolumetric flow rate through the fins, the thermal designer needs to determinethe total amount of flow which must be delivered in the duct or card passagecontaining the module w with heat sink. As shown in Figure 1, some of the flowwill go around or bypass the heat sink. In fact, depending … [Read more...]
- « Previous Page
- 1
- …
- 70
- 71
- 72
- 73
- 74
- …
- 78
- Next Page »