Sharif Digital Repository

Materials selection is an important stage in every mechanical or non-mechanical design. There are different methods for materials selection. Here, Digital Logic (DL) and Modified Digital Logic (MDL) methods are considered. Due to the shortcomings of these methods like requiring complicated functions etc., proposing a new method or modifying the existing methods was the main motivation behind the selected subject for the thesis. Particularly it is tried here to eliminate the existing shortcomings and simplifying the functions used for materials selection. The invented method is then applied to the existing and some new example problems. The areas of application of the so called... 

The major features of batch sublimation were investigated in an experimental-theoretical study. An experimental setup with real-time displays, sublimated dry ice blocks of different sizes, with circular or rectangular geometries. When temperature of hotplate was changed from -30 to 200 oC, heat transfer coefficient “hsub” decreased from 126 to 70 W/m2K, while thermal flux increased, linearly. Weight and area of the block had a positive/negative effects on “hsub”, respectively. In theoretical part, at first, two “linear-gradient” and “cubic” models were developed by a combined mass-momentum-energy balance. The latter used Von Karman temperature profile, and in cases of circular and...