Effect of mounting strut and cavitator shape on the ventilation demand for ventilated supercavitation

Insights into ventilation hysteresis shift due to flow unsteadiness in ventilated supercavitation

“…Froude number ( ) is calculated based on the cavitator diameter ( ). In the table, 5 refers to low and 15 refers to high hereafter, which is demarcated based on the bubble concentration regime from previous studies [6,11]. tilated partial-and supercavitation experiments [15][16][17].…”

“…. A FFM cone-type cavitator with a diameter of 30 mm has been employed, which is the exact same model as reported by [11] to facilitate the investigation of unsteady flow effects.…”

“…The measurements of these ventilation demands are recorded by changing the ventilation rates with an increment or decrement less than 0.05 SLPM to ensure a stable variation of ventilation rate and to accurately capture the critical value of and . The ventilation demands are investigated for 5 (low) and 15 (high) that represents different regimes of bubble size and concentration [6,11]. Particularly, the low regime, also referred to as the low bubble concentration regime, con- sists of a relatively bigger bubble size distribution [19], and increasing flow speed in this regime breaks up individual bubbles.…”

“…However, there is an inherent limitation with this type of cavitator configuration -it neglects the effects of the cavitator shape or the presence of the mounting strut, both of which have been shown to noticeably affect the cavity behaviors [7][8][9], especially the supercavity formation process [10]. Recently, Shao et al [11] studied the ventilation demands for a forward-facing model (FFM) with a variety of cavitator geometries (cone, disk, and nonaxisymmetric) to consider both the cavitator shape and the mounting strut effects. They have found out that the cone type cavitator required the least ventilation flow to form and sustain a cavity.…”

“…Therefore, as a follow-up study of Shao et al [11], we present a systematic examination of unsteady flow conditions, generated by the gust generator, on the formation and sustenance ventilation demand of FFM model (including the mounting strut effect) with a cone type cavitator which has shown to require the least ventilation demand to form and sustain the supercavity. The rest of the sections are as follows: Section 2 provides detailed explanation on the experimental methods.…”