Asymptotic expansions for the ergodic moments of a semi-markovian random walk with a generalized delaying barrier

In this study, a semi-Markovian random walk process (X(t)) with a generalized delaying barrier is considered and the ergodic theorem for this process is proved under some weak conditions. Then, the exact expressions and asymptotic expansions for the first four ergodic moments of the process X(t) are obtained.This research is supported partially by TUBITAK, under Project 110T559.Publisher's Versio

Modelling of Cohesive –Sediment Depositional Areas Carried by the Solaklı River to the Eastern Black-Sea

721-728In this study, cohesive sediment depositional areas carried by the Solaklı River to the Eastern Black-Sea are examined in the marine environment. Effects of changes in the amount of cohesive sediment entering the sea from Solaklı River, sediment drift velocity, direction and magnitude of wind-stream components are observed. For high sediment drift velocity, it is found that the affects of wind-stream components on deposition areas of cohesive sediment are very little. According to the results of the study, entrance angle of the stream mouth effects the deposition areas of sediment in the marine environment. Cohesive sediment depositional areas are examined on the charts by changing one of the parameters in the sediment transport model while keeping others constant

Drag Analysis of a Supersonic Fighter Aircraft

For aircraft design, drag optimization is very important for having better flight performance and less fuel consumption. In this study, drag effects of fuselage, wing and tail section are separately analyzed using a generic F-16 fighter aircraft model in ANSYS Fluent CFD tool with polyhedral mesh. Pressure drag and viscous drag effects are shown on different section of the aircraft as fuselage, wing, vertical tail and horizontal tail. Drag values are presented on subsonic, transonic and supersonic flights