Investigation on flow and heat transfer characteristics of impulse squealer tip

In order to study the aerothermal performance of impulse squealer tip, three impulse squealer and three assisted rib squealer configurations were investigated using numerical simulation method. The gap leakage flow field, tip secondary flow loss, tip total pressure loss and heat transfer coefficient were discussed in detail. The results showed that the squealer leading edge ribs suppressed the suction side branch of over tip leakage vortex, enhanced the over tip leakage flow separation in the squealer. With the same squealer depth, the relative total pressure loss of the double-ribbed squealer tips was the smallest, and the maximum decrease was up to 13% within the research range. The impulse squealer tip enhanced the leakage flow mixing in the squealer, reduced the kinetic energy of the leakage flow. With the same squealer depth, the relative total pressure loss of the impulse double-ribbed squealer tip was the smallest, and the maximum decrease was up to 18% within the research range. The impulse squealer tip reduced the leakage flow re-attachment on the cavity floor, increased the leakage flow re-attachment on the rim and rib surface of the squealer, and a high heat transfer coefficient area appeared on the rim and rib surface.