smooth surface 162 similarly the fourth side wall not shown likewise includes a substantially linear or smooth surface also not shown in a manner similar to that described above curvilinear surface portions 159 and 160 are shaped so as to guide the cooling flow from diffuser 30 into wheel space 34 at an angle flow control module 140 includes a flow control member 180 that selectively passively extends into flow passage 147 during off peak operation in accordance with the exemplary aspect shown flow control member 180 includes a bi metallic element 186 embedded in third side wall 156 more specifically flow control member 180 extends across or spans flow passage 147 and connects with first and second side walls 153 and 154 bi metallic element 186 includes a first member 190 that is joined to a second member not shown in a manner similar to that described above bi metallic element extends into flow passage 147 during off peak operation in order to reduce air flow passing into wheel space 34 and increase compressor flow passing to combustor assembly 20 to enhance combustion and reduce emissions while the invention has been described in detail in connection with only a limited number of embodiments it should be readily understood that the invention is not limited to such disclosed embodiments rather the invention can be modified to incorporate any number of variations alterations substitutions or equivalent arrangements not heretofore described but which are commensurate with the spirit and scope of the invention additionally while various embodiments of the invention have been described it.