Numerical Investigation of Near Wall Effect of Total Pressure Probe Based on CFD under Subsonic Velocity

Various sensors are used in the aero-engine during the test, and the probe as a contact measurement tool is bound to change the internal flow state of the flow field and affect the measurement accuracy. To study the effect of the wall on the total pressure probe, based on the numerical simulation, the influence of total pressure probes of four different structures(type A, type B, type C, type D) on the flow field and their own total pressure measured values under different near-wall distances is studied, then verifies the numerical simulation results with the experimental results. The results show that: the smaller relative near-wall distance c/d is, the greater the airflow deflection at the head of the total pressure probe, the greater the measurement error of the total pressure probe, the maximum value is less than 1%; when c/d>3, the total pressure measurement error is close to 0, indicating that the wall effect is vanished when the near-wall distance is greater than 3 times the outer diameter of the probe; influence of wall effect to measured values of the total pressure probes of the four structures are sequentially increased in the same condition; the uniformity of the measured flow field is reduced, and the velocity uniformity is the smallest behind the total pressure probe support rod