Advancement of Blade Tip Timing (BTT) Algorithms via Experimentally Validated Simulation Tools
Blade Tip Timing (BTT) technology is concerned with the estimation of turbomachinery blade vibration. Since it is non-contact and non-intrusive, it is significantly more reliable and cost-effective than the conventional alternative (strain gauge systems), resulting in multi-million pounds in cost benefits [1, 2]. A BTT system comprises two parts: (a) measurement system for blade tip arrival times (“BTT data”); (b) the analysis algorithms. Simulators that generate simulated BTT data under controlled conditions play an important role in the development of the algorithms since they enable an assessment of the performance of the different algorithms. Most simulators in the literature are based on a simple spring-mass-damper model and commercially available ones have no physical underpinning. Recent research at Manchester has introduced a realistic simulator based on the experimentally validated Finite Element (FE) model of a bladed disk (blisk). The proposed PhD research advances BTT research on two fronts:
• The simulator will be developed to accommodate aeroelastic and nonlinear effects to make the simulator more representative of real engine data.
• The effect of rapid speed changes on the BTT method will be explored.
The latter effect is particularly important since current blade tip timing algorithms assume an approximately uniform rotational speed over a given revolution and are considered applicable for rather low acceleration/decelerations. However, in the case of engine surge, when the airflow reverses, the engine rapidly decelerates. Future vehicles, particularly unmanned aerial vehicles (UAVs), will have engines that run at speeds up to 100,000 rpm and accelerate rapidly. The reliable use of BTT for such conditions requires the invention of new algorithms.
Applicants would be expected to have or develop knowledge in the following areas to conduct the PhD: Dynamics and vibration theory; experimental techniques in vibration testing; programming (preferably Matlab); Finite element analysis applied to dynamic analysis.
Funding is offered through the Engineering and Science Research Council (ESRC) for one PhD studentship to start in September 2019. The duration of the studentship is for 3 years and will cover both Home/EU tuition fees and a stipend to cover living costs at the RCUK-standard rate.
Further information about how to apply can be found at:
General enquiries relating to the postgraduate application process within the School of Mechanical, Aerospace & Civil Engineering should be directed to:
Martin Lockey, Senior PG Recruitment & Admissions Administrator (E-mail: [Email Address Removed], Tel: +44(0)161 275 4345)
 Olivier, J. Development of Blade Tip Timing Techniques in Turbo Machinery, PhD Thesis, University of Manchester, 2013 (Supervisor: Dr P. Bonello)
 Mohamed, E. M., Bonello P, Russhard P (2019), A Novel Method for the Determination of The Change in Blade Tip Timing Probe Sensing Position Due to Steady Movements, Mechanical Systems and Signal Processing , DOI: 10.1016/j.ymssp.2019.02.016