Design of Pitot-Static Tube Shapes and Their Influence on Airspeed Measurement Accuracy

Abstract

The conventional pitot-static tube’s accuracy in measuring indicated airspeed is compromised by its longitudinal inclination during forward flight, causing errors when the angle surpasses a critical threshold. This study aimed to propose and assess new designs for pitot-static tube ports to mitigate the angle of attack. Modifications, such as enlarging the inlet cross section, altering the tube port’s leading surface angle, and introducing new inlet openings, were implemented in five prototypes. After 2D CFD simulations, these prototypes were 3D printed, and experiments were conducted in a wind tunnel across angles from 0° to 55° at three airflow speeds. CFD results indicated increased error with larger inlet diameters and revealed an oscillating error phenomenon for multiple inlet openings. Experimental tests contradicted expected accuracy issues with extended diameters, suggesting superior characteristics at higher angles of attack. An oscillating error of pitot-static tubes with multiple holes was affirmed. The study targeted a pitot-static tube port design with a maximum 5% error in airspeed measurement within attack angles from 0° to 40°, showing promise for vertical takeoff and landing vehicle airspeed measurement during horizontal forward flight.