Effects of geometric properties of a static pressure tube on its frequency response.

Static pressure tubes are widely used to measure the static pressure in turbulent flows. Existing work focuses on the alteration of the static pressure tubes to the flow field. This paper investigates the effects of the geometric properties of a static pressure tube on the frequency response. A theoretical formulation is developed to describe the relationship between the sound pressure inside and outside the tube. The numerical simulation results show that the peaks in the frequency response move to lower frequencies when the tube diameter, tube length, and orifice depth increase and when the orifice diameter decreases. Experiments with a 3D-printed static pressure tube were conducted to verify the analytical results. The proposed model can be used to optimize the static pressure tube in the design stage or to correct the measurement results afterwards instead of cumbersome experimental calibration.