Sharif Digital Repository

A power plant cooling tower is like a tower, which needs to be studied very carefully from the aerodynamics point of view. Both the aerodynamics forces on the plume and intake stram are affected by the local winds and the performance of cooling tower decreases. There is a symmetric turbulent flow through the cooling tower if there is no. Wind blowing creates different vorticies, which appear in the lower section of the tower. Their periodic and wuick movments causes deficiency in towers performance and efficiency. Additionally there is wind effect on the plane of cooling tower and this causes a chocked plume which is named Wind Cover. The objective of this study is to decrease the adverse... 

Performing research and development in the field of modern vessel types which serve several functions is considerably necessary because of their importance and rapid development. HARTH vessel is considered one of the important ships which has been recently attracted much attention from the world. In this respect, a full investigation of its performance could make a big contribution to its optimum design and appropriate exploitation.“HARTH” ship is the abbreviation for “High Aspect Ratio Twin Hull” is included in the catamaran vessel category with a high aspect ratio with respect to their underwater cross-section’s ratio of length to width.A host of crucial issues should be considered for... 

The purposes of this research are one and three dimensional aerodynamic designs of a twin entry radial-inflow gas turbine's impeller. The GT4082 model Garrett turbocharger was chosen for this purpose. In order to predict existing turbine performance curves one dimensional model was prepared for whole turbine. For validating the 1d-modeling's results, widespread tests were performed on the turbine at Sharif University of Technology turbocharger lab. Comparing the results of 1d-modeling with experimental results, show 4.7% and 4% max difference for efficiency and mass parameter respectively. The wheel designing procedure started from primary design based on the mean line assumption, in 1-d... 

Let G be a graph. A twin edge k-coloring of G is a proper edge coloring of G with the elements of Z_k so that for every vertex u and v of G we have s(u)≠s(v), where s(u) is the sum of all colors of the edges incident with u. The minimum k for which G has a twin edge k-coloring is called twin chromatic index of G and denoted by χ_t^' (G). In this thesis we find the chromatic index of paths, cycles, complete graphs, complete bipartite graphs and some complete tripartite graphs. In 2014 it was conjectured that if G is a connected graph with at least 3 vertices and maximum degree Δ(G), then χ_t^' (G)≤Δ(G)+3  

In this research numerical and experimental study of a twin entry radial inflow gas turbine is performed. At first, various models of energy losses are investigated and compared and the most comprehensive combination of these models are selected. Using conservation equations, gas dynamics relations and energy loss models, the one dimensional model of radial inflow turbine is developed.One-dimensional modeling has lower computing cost in compare with two and three- dimensional models, while gives reliable results, Hence it would be the preferred option for turbine preliminary performance prediction. In this study the one dimensional model based on a step by step procedure, for each turbine...