Experimental and numerical investigations of the averaging Pitot tube and analysis of installation effects on the flow coefficient

Flows around a cylinder and other shapes, which imitate the cross section of an averaging Pitot tube, have been carried out using computational fluid dynamics. Correct calculations allow one to obtain the location of flow separation and the differential pressure between ports of the annubar. In numerical investigations the mesh concentration, turbulence models and turbulence intensity level at the inlet were taken into consideration. Pressure distributions around the cylinder surface was compared with experimental data. Moreover various shapes of the cross section were modeled to obtain a larger value of the differential pressure and a lower value of the permanent pressure loss. Experimental examinations concentrate on the determination of the flow coefficient K of the averaging Pitot tube and its relative change Δ K, which result from the installation effect. The results were presented as a function of the distance upstream of the annubar (between the element and the averaging Pitot tube).