Addressing Turbine Durability Concerns Associated with Imposed Transient Propulsion Needs

Addressing Turbine Durability Concerns Associated with Imposed Transient Propulsion Needs: Instrumentation is requested to quantify the transient effects of the turbine propulsion demands by the Navy. Specifically, these harsh transient conditions need to be better understood through time-resolved measurements of heat flux as well as flow and thermal fields to gain an understanding over a wide range of timescales that exist when operating a turbine imposed by the Navy to do their missions. The proposed instrumentation will be installed in a research turbine that has a range of operating condition with each condition being held in a steady, controllable state whereby engine Mach, blade Reynolds, rotational Reynolds, and cooling flows are matched using true-scale engine hardware. The proposed instrumentation will be used for two ongoing projects with federal sponsors through which advanced cooling designs are being investigated. Comparisons will be made possible between the proposed thin film heat flux gages and the long wave infrared method, which is being developed for use in these same projects. This proposal requests state of the art thin film heat flux sensors and a data acquisition system for turbine heat transfer measurements that is currently not being used in the United States, but yet has been shown to be accurate and highly reliable. Specifically for the heat flux sensors, technological advances whereby the amplification, acquisition, and storage of the raw signals take place on cards that are housed in the rotating shaft of the turbine. The advantage of having such a system is the increase in the signal to noise ratios, the measurement frequency, and ultimately the accuracy of the measurements. The proposed flowfield probe will provide valuable insight into the complex aerodynamics accompanying transient heat transfer effects in a turbine. In addition, the proposed instrumentation will provide a testbed by which more advanced sensors may be compared for Navy applications.