Numerical Simulation of Two Pass Gas Turbine Blade Internal Cooling Channels With 90 Degree Varying Height Ribs
Improvement in thermal efficiency of gas turbine can be obtained by operating it at high inlet temperatures. In addition to improving the performance, the cons of high inlet temperature is high thermal stresses on the turbine blades. To improve life and performance of the blade, improved cooling technologies are desired. The main objective of this paper is to perform computational analysis of the ribs with varying height and compare this with 90 degree ribbed channel and smooth channels. The numerical analysis is carried out using ANSYS-Fluent, a flow modeling simulation software. The flow is assumed to be steady state and flow turbulence is modeled using the k-ε with Standard Wall Functions. Local heat transfer and friction loss in a square duct roughened with 90 degree ribs with varying height is investigated for different Reynolds number. The pitch of the rib is considered to be 10 times the height of rib which is 0.0635 m. The square cross section of the channel is .0508x .0508 m2. The pitch of rib to rib height ratio varies from 10 to 20 at the center of the channel. There is a rib considered at the turn section as well. The numerical simulation produced higher heat transfer for the varying height ribs as compared to 90 degree ribbed channel and smooth channel.