The 7-hole pitot probe is a "professional tool" for 3D flow field measurements (e.g., aero-engine combustion chambers, rocket nozzles), and its hole layout directly determines analytical capabilities.5-Hole Pitotwelcome to click on the website to learn more!
Standard Layout Design:
- The head is spherical or ellipsoidal (to reduce airflow disturbance), with 7 holes arranged symmetrically as "1 central hole + 6 surrounding holes", with a 60° angle between adjacent holes;
- The central hole measures total pressure, and the 6 surrounding holes are divided into upper and lower layers (3 holes each) to resolve airflow deflection angles in horizontal and vertical planes (maximum measurable ±60°);
- Hole diameter must be ≤1/5 of the probe head diameter (e.g., φ1.5mm holes for a φ10mm head) to avoid airflow interference between holes.
Key Design Parameters:
- Spherical radius R = 3-5 times the hole diameter (excessively small R causes airflow separation at the orifice);
- The transition section between the probe stem and head must be streamlined (1:5 taper). In one test, an excessively steep transition section led to a 3% overestimation of turbulence intensity;
- For high-temperature scenarios (>800℃), zirconia ceramic material is required, and hole processing must use laser drilling (precision ±0.01mm).
Calibration Notes:
Full-angle calibration (every 5°) in a 3D calibration wind tunnel is required. Calibrated data must be fitted with a least-squares correction formula (a custom correction algorithm was once developed for a 7-hole probe in an aerospace laboratory, reducing errors from 3% to 1.2%).