The present paper deals with the characterization of heat transfer on blade tip Active Clearance Control manifolds. Real engine geometries and operating conditions were considered in validated CFD computations to understand the impacts of both manifold surfaces convective and radiative heat transfer on the aero-thermal performance of the system. Different manifold geometries were accounted for also.
The study sorted out that both the radiation and the convective heat transfer on the manifold surfaces are responsible of performance deteriorations as the impingement heat transfer on the casing is considered. The last evidence is motivated by the fresh fluid heat up along the feeding pipe. Radiative heat transfer from the casing to the manifold is found to be relevant, especially in case of high casing temperature or low undercowl flow rates. As a result of the study, is remarked that ACC manifold radiative and convective heat transfer should be considered for a proper system design.