The quality of information, which is necessary to help designers further improve turbine engine performance, requires sophisticated analytics working hand-in-hand with well-developed experimental methods. Historically, the test instrumentation used in harsh, real engine conditions was short-lived, invasive, and not very accurate. This was accepted as the practical reality and the data obtained in an engine test cell had been used as little more than a sanity check or a trend indicator during the design process. Today expectations are much higher and the challenge is to develop experimental tools that can deliver the accuracy required to verify analytical predictions, calibrate computer models and to provide ground for critical design decisions in a way which was not possible before.
Successful introduction of UCTS (Uniform Crystal Temperature Sensor) Technology to the leading engine manufacturers demonstrated that it has the potential to overcome the typical issues of testing in a real engine environment. It is robust, non-intrusive and capable of high accuracy temperature measurement. It is based on the mechanism of heat transfer conduction, of which the fundamental theory is rigorous and simple. Our experience has shown that in order for a UCTS-based system to realize its promise, all potential sources of error must be tightly managed. LG Tech-Link identified important factors of influence that could complicate measurement and increase its uncertainty. Among them are variations in the part’s geometry, TBC thickness, boundary conditions, and installation methodology. These have been selected as the focus of this study.
The authors of this paper are using 3D Finite Element Analysis (FEA) methodology to investigate the possible pitfalls in the process of UCTS application that could cause loss of accuracy. It is the authors’ intention to probe the sensitivity of temperature at the location of the sensor to the major technological factors. The findings emphasize the value of collaboration between instrumentation, test and analytical engineers when planning engine tests and interpreting their results. Practicing engineers will be able to use the presented recommendations, methodologies and case studies to ensure the application of UCTS in their projects is accurate, compatible with test objectives and cost effective.
