The disclosure relates generally to turbine systems, and more particularly, to a cooling circuit for a tip area of a multi-wall blade. 
Gas turbine systems are one example of turbomachines widely utilized in fields such as power generation.  A conventional gas turbine system includes a compressor section, a combustor section, and a turbine section.  During operation of a gas turbine system, various components in the system, such as turbine blades, are subjected to high temperature flows, which can cause the components to fail.  Since higher temperature flows generally result in increased performance, efficiency, and power output of a gas turbine system, it is advantageous to cool the components that are subjected to high temperature flows to allow the gas turbine system to operate at increased temperatures. 
Turbine blades typically contain an intricate maze of internal cooling channels.  Cooling air provided by, for example, a compressor of a gas turbine system may be passed through the internal cooling channels to cool the turbine blades. 
Multi-wall turbine blade cooling systems may include internal near wall cooling circuits.  Such near wall cooling circuits may include, for example, near wall cooling channels adjacent the outside walls of a multi-wall blade.  The near wall cooling channels are typically small, requiring less cooling flow, while still maintaining enough velocity for effective cooling to occur.  Other, typically larger, low cooling effectiveness internal channels of a multi-wall blade may be used as a source of cooling air and may be used in one or more reuse circuits to collect and reroute “spent” cooling flow for redistribution to lower heat load regions of the multi-wall blade.  At the tip of a multi-wall blade, the near wall cooling channels and low cooling effectiveness internal channels are exposed to very high heat loads.