Study on the influence of active jet parameters on the cavitation performance of Clark-Y hydrofoil

Abstract

Cavitation is a phase change that severely endangers the safe and stable operation of hydraulic machinery. At present, one of the effective methods to control cavitation is the active jet. However, limited literature reports on multi-parameter optimal control of cavitation flow consider jet direction, flow, and position at the same time. This study attempts to fill this gap by determining the transient interaction mechanism of active jet and hydrofoil cavitation flow and to reveal the relationship between active jet and cavitation development. Clark-Y hydrofoil is taken as the research object and the grey Taguchi algorithm is used to obtain the optimal scheme of lift-drag ratio and hydrofoil ratio. The large eddy simulation combined with the Zwart-Gerber-Belamri cavitation model was used to numerically simulate the orthogonal test program and optimize its performance. Results are as follows: The closer the jet position to the leading edge of the hydrofoil, the easier it is for the active jet to block the back jet, reducing the cavity volume and hydrofoil drag but reducing the lift coefficient; The hydrofoil shows the best hydraulic performance when the jet position and the leading edge of the hydrofoil has a distance x of 0.3L (L is the chord length), the jet ratio u/u0 is 0.3, and the angle θ between the jet and the horizontal plane is 22°; Using the optimal jet scheme increases the lift-drag ratio k of the hydrofoil by 11.43% while the cavitation volume fraction is reduced and only 30% of the original hydrofoil.