Patent attributes
A turbine blade with a spar to support a thin thermal skin for the outer airfoil surface. The spar includes multiple rows of impingement cooling cavities that are each connected in series through curved impingement cooling holes to provide cooling for the airfoil walls. The spar is hollow on the inside and open at the blade tip with a blade tip rail extending along both walls and around the leading edge. The impingement cooling cavities discharge the spent cooling air through the tip cooling holes. A thin thermal skin is bonded to the spar to form the outer airfoil walls and is cooled by the series of impingement cooling cavities to provide a low metal temperature using a low volume of cooling air. The impingement cooling cavities and the curved impingement cooling holes are formed in the cast spar by drilling or machining so that a ceramic core for the cooling holes and cavities are not needed and blade casting yield is improved.
