This paper experimentally and numerically examines non-circular hydraulic jumps caused by oblique impact of circular water jets on horizontal surfaces. The main aim is to describe the flow field deformation, measure the stagnation point displacement and outline the geometry of the hydraulic jump with respect to the jet inclination. Jets of 6 mm to 12 mm diameter, inclination angles of 30 to 90° and volumetric flow rates of 1.67 \(\:\times\:\) 10−5 to 1.67 \(\:\times\:\) 10−4 m3/s were used in experiments. The computations were done by numerical simulations using the Volume of Fluid (VOF) method in ANSYS Fluent, which uses conservation equations of mass and momentum to simulate two-phase flow. A dimensionless scaling relationship for stagnation displacement is proposed and validated. The findings show that the stagnation point moves upstream by up to 3.4 mm at a 45° inclination, which increases with the radius of the jet and decreases with the angles of inclination, but is independent of the flow rate. The non-circular jump profiles predicted vary within a range of less than 4.8% of the experimental data and show a close correspondence with the analytical model in the literature. The aspect ratio of the elliptical jump is smaller at a 30° inclination of about 2.5 to almost 1.0 at 90°, and thus confirms the analytical relationship established. The results provide more information on the hydrodynamics of oblique jets, which can be used to support the optimization of designs in heat-transfer, cooling and surface-treatment applications. This study goes beyond earlier geometric descriptions by measuring stagnation point shift and showing its independence from flow rate. Using combined experiments and simulations, it predicts jump deformation and identifies the transition from elliptical to nearly circular profiles.
