Flow and heat transfer characteristics in cooling lamilloy with internal MCs

Lamilloy is considered a promising cooling concept that can meet the requirement of high cooling effectiveness and low coolant consumption requirements. A new lamilloy structure with internal minichannels (MCs) is put forward to effectively cool modern advanced gas turbine combustors, periodically arranging staggered internal MCs in the lamilloy. An experimental system is built to study the cooling performance on the surface suffering the mainstream of lamilloy, and the effect on the cooling performance of mass flux ratio ( m *= 4.37-7.87) and temperature ratio ( T *= 0.56-0.76) are investigated and compared. The cooling effectiveness is found to increase with the increase of m * and T *. The flow field structure shows that the internal MCs can obtain the superposition of impingement cooling at the inlet, the convection cooling in the MCs, and the film cooling at the outlet. Compared with single film cooling, the lamilloy can be cooled by coolant flowing through the internal MCs, where the average cooling effectiveness can be improved by 3.7 to 4.5 times under three different m *. The research herein provides some references for designing the cooling structure of combustors.(c) 2022 Elsevier Ltd. All rights reserved.