Abstract: A method for improving the cooling effectiveness of a gaseous coolant stream which flows through at least one passage hole in a substrate to an exit site on a high-temperature surface of the substrate is disclosed. The method comprises disrupting the coolant stream at the exit site, so that the coolant stream contacts a greater area of the high-temperature surface. In some embodiments, the exit site is a crater. Moreover, the exit site may be formed within a coating applied over the substrate, e.g., a thermal barrier coating applied over a superalloy substrate. Related articles are also disclosed.

Abstract: A fuel injector is cooled by steam during operation of a combustor. The injector includes a conduit for channeling fuel into the combustor, and a jacket covering the conduit through which steam is channeled for cooling the injector. The steam may be mixed with the fuel, or kept apart from the fuel in the injector by flowing through passageways in the jacket. Cooling can be further improved by expanding the steam through an orifice prior to entry into the injector.

Abstract: Methods of making gas turbine structures with cooling channels, such as, for example, combustor/transition pieces for gas turbines having a double wall with a plurality of cooling channels, having axially and/or circumferential cross-flow passages positioned between the structure's inner member and the outer member to provide cooling air thereto, are disclosed.

Abstract: A method of superficial laser induced fluorescence for measuring film cooling performance within a fluid tunnel apparatus includes the step of introducing a test fluid uniformly dyed with a fluorescent dye into the fluid tunnel apparatus so as to surround a cooling model having a test geometry. The cooling model is positioned adjacent to a laser sheet. A background fluorescent image of the test fluid about the cooling model is recorded. The test fluid is then flushed from the tunnel apparatus. Next, a cooling simulation fluid flow and a hot gas simulation flow are introduced within the fluid tunnel apparatus. The cooling simulation fluid contains the same fluorescent dye concentration as the test fluid and the hot gas simulation fluid contains no fluorescent dye. A data image of the cooling simulation fluid flow is recorded about the cooling model as the cooling simulation fluid flow passes through the cooling model and into the hot gas simulation fluid flow.

Abstract: A combustor/transition piece for a gas turbine including a double walled structure having a plurality of cooling channels, both axially and, in some cases, circumferential cross-flow passages positioned between the structure's inner member and the outer member to provide cooling air thereto, are formed in the area between the inner member of the combustor and the outer member thereof. The passages preferably extend both axially and circumferentially with respect to the direction of flow through the combustor/transition piece. The axial passages extend completely from one end to the other and the circumferential passages extend around the circumference of the combustor/transition piece. The addition of a circumferential cross-flow passage connecting axial flow coolant passages in double wall turbine components can prevent combustor/transition piece part failure due to axial passage inlet blockage without affecting normal, unblocked cooling.