Use of the Hot Wire Anemometry for Velocity and Temperature Measurements in a Turbomachine

Sami Blidi , Hubert Miton

The hot film anemometry in a highly heterogeneous unsteady flow is a quite complex measurement technique. The velocity is determined from the heat flux measurement. The part of the signal related to velocity must be kept apart from one related to temperature and to pressure of flow. After a brief return to the principle of hot wire anemometry and the different heat transfer models between hot wire and flow, an experimentally established heat flux expression is presented. This study was achieved in view to measure the instantaneous velocity fields between blade rows of a low speed axial compressor by means of a crossed hot film probe. In such a turbomachine, the flow is highly tri-dimensional and unsteady. Although compressor rotating speed is relatively low (4500 rpm), the spatio-temporal fluctuations of flow temperature are not negligible. Knowledge of temperature is then an important objective, for itself on the one hand, and by its influence on the measurement of velocity on the other hand. The simultaneous measurement of these two parameters would then be a quite interesting solution. For this purpose, an original apparatus including a standard model constant temperature anemometer has been set out. Its main advantage is to require only the use of an external small cabinet which commutes the probe overheat temperature. System utilisation limits, especially in frequency have been brought to the fore. The operating method and achieved results obtained in 1 compressor are presented in this paper.

Domaines: Articles anciens

Sami Blidi, Hubert Miton. Use of the Hot Wire Anemometry for Velocity and Temperature Measurements in a Turbomachine. Journal de Physique III, 1995, 5 (10), pp.1513-1535. ⟨10.1051/jp3:1995208⟩. ⟨jpa-00249399⟩