Extended Numerical Analysis on Gas Turbine Blade Cooling

The main objective of this project is to simulate the Gas Turbine blade cooling by Finite
Element using ANSYS-FLUENT software. Using Gambit and Fluent software, the
effect of the channel ribbing configuration on the cooling efficiency is investigated. A
real gas turbine blade (!43MW ABB GTI3E2) contributed by Lumut Power plant was
used for the studies. The blade was then taken for digitizing to get the real dimension in
the form of AutoCad drawing. The drawing was then export to Gambit for further
analysis such as meshing and boundary condition setting. Once the setting been done in
Gambit, it will then be exported to Fluent for simulation.
Grid Independency is an important issue whereby we will look at the starting size,
growth rate and size limit for meshing the blade. A small size and growth rate will
result in a large total of element in which in return will give trouble to the simulation.
Flowing into a rectangular 9mm x 18mm channel, the 400K compressed air is used to
cool the blade while the blade is spinning in the hot gas of 1700K. The temperature
distribution is then compared to the result using analytical method (Matlab) done by
previous student. The result shows that the temperature difference is less than 5% for
the root of the blade and 15.92% for height of !57 .7mm channel.
From the study done by previous student a rib channel with rib angle, a = 60° and rib
blockage ratio, e!Dh = 0.078 will result in largest convection coefficient which is
Hc;bbed= 559.32 W/m2.K. This parameter of ribbed channel will then be compared with
smoothed channel cooling. The result shows that there a decrease in temperature which
brings to 8.68% more efficient if using two-opposite rib wall.