Measurement of Instantaneous Pressure and Velocity in Nonsteady Three-Dimensional Water Flow by Means of a Combined Five-Hole Probe

Abstract

A new combined five-hole probe with hemispherical head of 2.0 mm diameter is developed for the measurement of nonsteady three-dimensional water flow. Each pressure hole is connected to a small semiconductor pressure transducer, which has a high frequency response, and the instantaneous pressure can be measured continuously by the probe. In the case of nonsteady flow, pressures detected by the probe are affected by the inertia due to flow unsteadiness. Therefore, in order to achieve an accurate nonsteady flow measurement, it is vital to reduce the inertial effects from the pressure reading. In the present study the inviscid flow analysis was carried out to evaluate the error due to the inertial effect, and the iterative correction procedure was examined by computer simulation.