Experimental and numerical optimization of orifice entrance conical geometry in a multi-hole plate to reduce the plate pressure loss

Multi-hole plates are extensively used in various flow systems in order to overcome the distorted flow issues or to achieve high pressure drops, however, they cause significant pressure losses that lead to high pump power consumption. In order to make an improvement, the present study proposed conical-edged orifice entrance for multi-hole plate that can be through its optimization to minimize the pressure loss caused by its sharp square-edged orifices. In this regard, conical-edged multi-hole plates, each the same in the distribution of eight holes and their diameters but distinguished by conical angle (θ) and relative conical height (h / t), were optimized experimentally and numerically with water flows inside a circular test pipe by varying pipe Reynolds number (368 ≤ Re ≤ 33909). The results analyzed graphically showed an optimum conical angle about 20 degrees at the point of minimum pressure loss as a regardless of Re and h / t, in a capability reduced the pressure loss caused by sharp square-edged multi-hole plate by 23 −53 % and with an improvement steeply raised with Re. A formula predicting pressure loss as a function of Re and h / t was developed for 15, 20 and 30 degree conical angles. Published empirical formulas were utilized also to validate the obtained results both experimentally and numerically.