Turbine blade with cooling flow modulation

摘要

A turbine rotor blade with a 3-pass serpentine flow cooling channel having a first leg located at the leading edge of the airfoil and a third leg located adjacent to the trailing edge of the airfoil and connected to a row of exit slots, and in which a second leg includes three separate channels in parallel with inlet metering holes to regulate a cooling air flow and pressure in each separate channel. The blade includes a blade tip channel connected to the first leg of the serpentine and which supplies the cooling air to the second leg channels through the separate metering holes. Because the metering holes can be sized individually, the hottest part of the mid-chord region of the airfoil can be supplied with more cooling air flow and the pressure ratio across the trailing edge can be reduced so that the exit slots can be larger or more numerous.