چكيده به لاتين
In all classes of gas turbine, cooling of stationary and rotary blades is a fundamental matter and is of more significance in the first rows of gas turbine blades. Regarding the temperature limitation of the alloys used, employing cooling methods to decrease turbine component temperature especially blade is crucial. Using modern methods of blade cooling, increase of turbine inlet temperature becomes possible which leads to increase of efficiency and power generated by gas turbine. Since turbine blades rotate with high rotational velocity, blade cooling is influenced by blade rotation. Blade rotation brings about rotational secondary flows and increases flow mixing and heat transfer.
Based on the research conducted in this field, cooling, using rib turbulators has a higher heat transfer coefficient among other proposed technologies. This thesis conducts an investigation and feasibility study on different methods of internal cooling using various proposed turbulators to be used in gas turbine blade from flow and heat transfer point of view and then compare their heat performances. In this work, 3-D simulations have been carried out for multiple types of rib methods, two types of pin-fins arrangement, extended surfaces and matrix geometry in a straight rectangular and U-shaped channel in stationary and rotary status. The results indicate that among the common methods used in trailing edge of gas turbine blade, circular pin-fin method has the highest heat performance in stationary and rotary status. Among methods used in halfway paths of gas turbine blade, the new matrix geometry method exhibits high heat performance. Also, it is observed that using U-shaped paths increases performance of the ribs inserted in them by changing the flow behavior in stationary and rotary status.
