FLOW CHARACTERISTICS OF SECTOR ORIFICE PLATES

Abstract

ABSTRACT The results of an experimental investigation concerning the characteristics of flow through sector orifice plates in a circular pipe have been reported. Experiments were conducted in a pipe line having diameter of 40 mm and using sector orifice plates with ratios of orifice area to pipe area a/A = 0.20,0.35,0.50,0.65 and 0.80, and having corresponding central angle values θ = 72°, 126°, 180°, 234° and 288°. The data collected in the present study indicate that for clear water flow through sector orifice plates, location of vena contracta is a function of area ratio a/A or central angle θ. The discharge coefficient Cd depends on a/A (or θ), orifice Reynolds number Rd (= 4VR/μ) and pipe Reynolds number RD (= UD/μ). For Rd greater than 1.0 × 105, the value of Cd depends only on a/A or θ- Analysis of the data collected in the present study has been carried out and the discharge equation Q = 3.857 × 10−3 (a/A)1.18 (Δ H)0 50 or Q = 4.41 × 104 (θ)1.18 (Δ H)0.50 for sector orifice plates has been obtaine...