SHIP GAS TURBINE AIR INTAKE DUCT DESIGN

A numerical study was conducted to design gas turbine air intake geometry which plays a vital role to increase engine performance. This thesis addresses the solution of the optimal duct geometry in which intake air pressure loss must be minimum and outlet flow conditions must be uniform.

The calculations were carried out using the commercial CFD package Fluent, which uses finite volume method for discretization and were first benchmarked against known results in the literature for the simpler case of Stanitz Elbow.

In this work 2D and 3D models of intake geometries were composed and meshed with the commercial pre-processor Gambit package. At the end of the flow analysis simulations, the optimal duct geometry was created. Eleven 2D models were analized and the best 2D model was picked out in order to create 3D model of the geomerty. Several improvements in the entrance geometry were done and finally the optimal 3D model was created. Furthermore 3D flow analysis were carried out.

The segregated implicit solver, compressible flow, k-epsilon turbulance model and mass flow inlet, pressure outlet, standard wall boundary conditions were used in the CFD package Fluent. In composing the optimum geometry, the main design factors were: total pressure loss, total pressure distribution in exit plane, uniform distiribution of velocity component perpendicular to exit plane and construction difficulties.