Forced Convection Heat Transfer in Channels with Rib Turbulators using CFD
International Journal for Research in Applied Science and Engineering Technology
To achieve high thermal efficiency in a gas turbine engine, the temperature of the turbine inlet gas must be increased. However, the penalty is a high heat load, which affects the durability of the turbine components. Therefore, improved cooling technologies such as film cooling and internal cooling are applied to the turbine blades. Inner cooling is achieved by circulating low enthalpy air in multiple flow channels inside the blade structure. To increase heat transfer from internal cooling,
... nternal cooling, internal surfaces are generally hardened by angular ribs to move the boundary layer and increase turbulence. Computational fluid dynamics study was performed to obtain heat transfer data for a two-pass rectangular channel with two passes (2: 1 aspect ratio) with smooth and sheared surfaces for two-channel directions. V-shaped ribs are placed on the front and back surfaces. Seven different V-shaped rib arrangements with a 45-degree angle were studied. Reynolds numbers for the study are determined as 5000 and 40,000 and the aspect ratio of the rib to the hydraulic diameter is 0.094, the aspect ratio is 10, and the density ratio the refrigerant of the inlet wall is kept around 0.115 per test. CFD studies are conducted on arrays of parallelograms of V-shaped by 45 ° and produce a better increase in heat transfer than inverted ribs of V-shaped by 45 ° and crossed ribs of V-shaped by 45 ° to determine the best heat transfer and increase of flow. CFD is used to predict the bulk temperature inside the channel channel through which the heat transfer coefficient is reached. Comparing the Nusselt number between the different matrices gives an idea of the improved heat transfer.