Flow characteristics of back supported V-cone flowmeter (wafer cone) using PIV

The present experimental study has been carried out to evaluate the performance and flow characteristics of the Wafer cone flowmeter using Particle Image Velocimetry (PIV). Two equivalent diameters (β) of 0.62 and 0.72 with combination of two vertex angles (ϕ) namely 30°and 45°are used for the evaluation of the performance of the flowmeter in the range of Reynolds number of 3 × 103 to 8.19 × 104. The investigation shows that the coefficient of discharge seems to be independent of β-value with the increase in vertex angle. Further, the appropriate location of the downstream pressure tap is also estimated for the cone configuration of β = 0.62 and ϕ = 30°. It is observed that the downstream pressure tap location of 0.8D distance gives a higher value of discharge coefficient compared to 0.0D distance with the error being also lower marginally. PIV data has been analysed for the cone configuration of β = 0.62 and ϕ = 30°at four Reynolds numbers of 3028, 6057, 52755 and 74488 in terms of axial velocity and turbulent intensity. The measurements reveal an interesting phenomenon in terms of the rapid decay of turbulent kinetic energy on the downstream of the cone. This may be due to the interference of the cone wake with the support wake resulting in fast decay. This unique phenomenon leads to the reduction in the requirement of the downstream straight length for the Wafer cone flow meter, unlike other obstruction type flowmeters.