High speed rotor wake total temperature measurements using a hot-film anemometer

• Published in: Experiments in fluids 1998-09, Vol.25 (4), p.337-346
• Main Authors: JOHNSTON, R. T, FLEETER, S
• Format: Article
• Language: English
• Subjects: Applied fluid mechanics; Exact sciences and technology; Fluid dynamics; Fundamental areas of phenomenology (including applications); Hydraulic and pneumatic machinery; Instrumentation for fluid dynamics; Physics
• ISSN: 0723-4864; 1432-1114
• DOI: 10.1007/s003480050238

To develop a quantitative understanding of unsteady and interacting turbomachine flow fields, it is necessary to quantify the instantaneous efficiency of high-speed turbo-machines. This requires the measurement of both the unsteady velocity and total temperature variation in the exit flow of a high speed rotor. In this paper, techniques to utilize a single slant-film anemometer to measure unsteady total temperature are developed and evaluated. A series of preliminary experiments are performed in a high-speed axial fan facility to quantify the instantaneous rotor efficiency. This is accomplished by utilizing these single slant-film methods to measure the total temperature in the rotor wakes. Results show that measurements at multiple overheats and several probe orientations are required. The simplest method proves to be useful for determining parameters used in other methods. An analysis based on King's law gives good results even when measurements are outside the calibration range. Within the calibration range, a polynomial representation of the wire response to mass flux and total temperature yields good total temperature fluctuation results. A model analysis technique is also assessed. (Author)