Influence of Force Field Direction on Pressure Sensors Calibrated at Up to 12,000 g

The measurement of pressure within both stationary and rotating frames of reference is a fundamental requirement when studying the flow field through turbomachinery blading. Measurement of pressure within the rotating frame presents a particular challenge, as centrifugal acceleration of the sensor can have a significant impact on sensor calibration, and therefore accuracy of the resulting measurements. In this paper the telemetric calibration of pressure sensors at up to 12,000 g is described, and the impact on calibration of membrane size, sensor body shape, and sensor mounting direction is discussed. The program of work reported in this paper focuses on experimental issues associated with rotating pressure measurement. The combined effect of centrifugal load and pressure on integrally temperature compensated silicon pressure sensors is presented. Experimental results are given that provide insight into the influence of acceleration on pressure readings. Implementation of acceleration into sensor calibration is presented. Supplementary finite element calculations enable impact of sensor body shape to be taken into account during the evaluation of sensor acceleration-to-pressure sensitivity ratio. Different sensors with varied membrane sizes and acceleration force directions are examined and compared.