مجله فناوری اطلاعات در طراحی مهندسی
سال یکم شماره 1 (تابستان 1385)

In this paper it has investigated condensation phenomena, steam flow, liquid appear in a supersonic convergent-divergent nozzle, and comparison theoretical results with experimental conclusions. While in the nozzle supersonic section, condensation has done, the released latent heat due to condensation, causes reduction mach number to one and making instability flow. In this way, a condensation shock has made in the steam flow. The received results has shown that situation of this shock, is sensitive to initial static pressure and temperature, wall friction factor respected quantities, condensation coefficient, and surface tension changes in the small liquid droplets. In addition, application of the classical nucleation equation with barschdorff correction and tacking condensation coefficient equal to one has made an excellent conformity between one-dimensional theoretical conclusions with experimental results.

Rutting is one of the most important factors to evaluate the pavement condition. This factor have been effected by only type and construction, but also is effected by environmental parameters. Planning for pavement management as programming for repair and maintenance is necessary for prediction of rutting increases. In this research have been found the rutting deep increases on the differential environmental zones, traffic volumes, sub grade condition, and thickness of asphalt concrete layer with use of long term pavement performance data of asphalt concrete pavement with gravel base. The result of this research shown that rutting deep for wet no freeze zones is increase more and on dry no freeze zone is less deformation rutting deep is more effected by traffic on the thin pavement(less than 3 inches) and thickness pavement(more than 8 inches) than middle pavement(between 3 and 8 inches).

Titaniun aluminide intermetallic compounds are a new family of advanced materials with uniqe properties. These materials are considered as candidates for replacement of Ni-based supper alloys at high temperature. The behaviour of Ti-48Al-2Cr (at percent) intermetallic compound in pressure test at different temperature were investigated in this study. The intermetallic compound was produced via KRH procrss followed by induction remelting and heat treatment. On the basis of achieved results despite of single crystalline compounds the yield strength of present cast compound have conventional changes with temperature. The pressure ultimate strength is nearly constante at a temperature range from room temperature up to 700°C. In this temperature range the ultimate strength varied from 1063 to 1135 Mpa. With more increase in temperature, the ultimate strength decreased. The results show that the Young,s Moduli of the compounds at different temperature, is considerably less than crystalline compounds and is close to Young,s Moduli of porous compounds.

This paper present a new method for determine functional controllability and optimal time problems of nonlinear dynamical systems by using measure theory. This problem transfer to an optimal control problem, then it problem transformed to measure space and using measure theory the problem changes to an infinite dimensional linear programming problem. Then by a suitable approximation the problem changes to a finite dimensional linear programming problem. By solving the linear programming problem control Function can determine such as a piecewise constant function.