Assessing the Feasibility of Marine Gas Turbine Combustion Chamber Cooling by Porous Media

The technology of marine gas turbine is being developed toward higher efficiency and lower cost. The biggest setback to progress is the issues corresponded to cooling of combustion chamber so that as the temperature rises further, the materials melt and it is impossible to increase the engine power or travel time. One of the most useful idea is utilization of porous media in the path of coolant fluid. The main advantage of this study is in using no simplifying assumptions and its significant proximity to practical conditions such as using real geometry and boundary conditions, local thermal non-equilibrium model to model porous medium, and taking into account the variation of physical properties due to fluid's temperature. Influences of various parameters including fluid type, porous media’s material and porous holes sizes in wide ranges of the Reynolds number and heat flux were investigated, comprehensively. It was revealed that using hydrogen as a coolant with insertion of 20 PPI Nickel porous media presents the best condition for cooling of combustion chamber which on average reduce the maximum temperature of walls about 60% for different Reynolds numbers in comparison with the simple conduit. This condition is accompanied by approximately 5 kPa pressure drop.