New Numerical and Statistical Determination of Probes' Arrangement in Turbo-machinery

Purpose Blade tip timing (BTT) is a promising non-contact method for the measurements of blade tip displacement in turbo-machinery. Despite the advantages, this method offers, one of its drawbacks is the highly under-sampled data measured. The quality of these data depends on the position of the probes in the engine casing. This work aims to determine the placement of the probes for which the highest quality of data, hence the best accuracy of the vibration parameters are obtained. Methods Thus, the present work proposes a statistical BTT method based on the minimization of some statistical variables to determine the placement of the probes. Results This work presents a defined number of probes, which of the regular and irregular probe arrangement leads to the determination of vibration parameters with higher accuracy. It is found that mostly all the subsets with probes irregularly spaced are the ones giving a better accurate estimation of the amplitudes. Conclusion This work has proposed statistical methods of determination of the probes arrangement, based on the minimization of the RMSE in the case of synchronous vibrations and the combination of synchronous and asynchronous vibrations. In addition, we have shown statistically that in almost all the scenarios considered, the irregular probe placements are the ones for which the vibration parameters are obtained with the highest accuracy.

Automated summary

This study proposes a statistical BTT method based on the minimization of statistical variables to determine the placement of probes, in order to obtain the highest quality data and the best accuracy for vibration parameters. The results show that irregular probe arrangements can estimate amplitudes more accurately.