Characteristic length and cooling circle
Modular design, outsourcing and open innovation create a complex network of possible end product embodiments in product design for the consumer market. Analyzing each and every possibility in detail is out of the question as resources are limited and module details are often proprietary information. To meet this challenge the thermal engineer needs a feeling about what will and what will not work out, without getting bogged down in too much detail. This paper presents the concepts of characteristic length and cooling circle as an approximate measure for the extent of heat spreading in beam and in flat thin plate geometries. Beam and flat thin plate geometries are widely used by mechanical designers, and being able to assess how much of the geometry is actually thermally affected by a heat source is of great value in thermal decision making and communication. For both geometries an application is discussed and compared to CFD simulations to assess the validity of the approach.
Sense and Nonsense Thermal Requirements
Good thermal requirements form the basis of a good thermal design. Unfortunately, good, workable thermal requirements are a rare commodity. This paper discusses thermal requirements from the semakers thermal system designer’s point of view. Different types of thermal requirements are discussed, and different ways of specification. The famous “max operating ambient “ specification is discussed, and a method is presented to get a handle on this difficult specification. The method is demonstrated on CFD calculations on a consumer display product.
Neotectonic rotations in the Orava-Nowy Targ Intramontane Basin (Western Carpathians): An integrated palaeomagnetic and fractured clasts study
Abstract The objectives of this contribution are: (1) to promote the application of fractured clasts analysis in conglomerates for regional stress reconstructions and (2) to advance reconstruction of the Western Carpathians structural development. Our results show that the Neogene fill of the Orava-Nowy Targ Intramontane Basin underwent CCW rotation of about 30°. We infer that the rotation terminated after 8 Ma and was related to shift along NW-SE to NNW-SSE trending faults at the NE termination of the sinistral Mur-Žilina Fault Zone. Our results show that, fractured clasts analysis can be good tool for regional tectonic reconstructions. The tool is especially useful when other tectonic tools are scarce or absent. Results of our palaeomagnetic study and fractured clasts analysis verify and supplement each others. In the studied case, palaeomagnetic results allow to distinguish between regional stress field rotation and rotation of the Orava-Nowy Targ Basin Neogene fill, whereas, results of fractured clast analysis help to constrain the age of rotation.