Raising the combustion temperature continues to be a major driver for increased overall efficiency of industrial gas turbines. Therefore, active cooling has become a necessity as gas temperatures have surpassed the allowable temperature of the base material. Thus, cooling schemes need to be improved for higher heat loads. However, the thermal efficiency of cooling schemes, which can be manufactured employing conventional machining has stagnated. With the geometrical freedom offered by Additive Manufacturing (AM), advanced cooling designs for gas turbine parts have become viable and can provide superior thermal efficiency. A promising cooling design approach which exploits this freedom is In-Wall cooling. Here cooling channels are placed within the structural wall close to the heat-loaded surface. An AM ring segment for an industrial gas turbine with such a cooling scheme has been investigated experimentally. The influence of the friction factor uncertainty of AM macro channels is quantified in terms of mass flow.  In order to develop this design approach further, In-Wall cooling schemes for such ring segments have been modelled numerically with different topologies and varying design parameters. These include channel pitch, channel size, inlet location and distance from the heat-loaded wall. The impact of the parameters on the thermal efficiency as well as the temperature uniformity are quantified. The most important design parameters of such an in-wall cooling scheme are identified. This work can help designers focus on the most important factors when designing a new in-wall cooling scheme and shows how the capabilities of AM can be employed in gas turbine cooling design.


Numerical Investigation of an In-Wall Cooling Design Approach for Improved Thermal Efficiency of Additively Manufactured Gas Turbine Ring Segments

Division / Sponsor:
International Gas Turbine Institute (IGTI)

Paper Proceedings: https://asmedigitalcollection.asme.org/GT/GT2020/volume/84058

Turbo Expo - Virtual Conference

Supporting the need among researchers worldwide for additional online and multimedia content, ASME now offers the ASME Conference Video Collection. This platform will collect and provide long-term access to conference presentation videos, encompassing all technology areas within ASME's technical conference and events program. About 30,000-40,000 engineers across all mechanical engineering and related disciplines participate in ASME conferences each year. This includes authors of approximately 6,000 to 8,000 technical papers published by ASME, the majority of whom also submit video presentations for our virtual conferences. The video collection will be available as an add-on to existing product packages or as a separate subscription.