dear concerns,

i am meshing a tank  and impeller seperately. i need total number of cells 299616 when i send both meshes in the fluent solver but i am not having this numbe of cells. element size at 1mm i have 2215223 and at 1.5 mm i have 1316002. i am doing validation case and in the article they used unstructured tetrahedral mesh and no of elements 299616 so i need this much no of cells. 

when i further increase the element size it i gives constant number of cells that is 1316002 even i increase the element size uptill 500 m of impeller size and 1000 m of tank size but when i update mesh it gives the error execution error inside the mesher

what should i do to achieve number of cells 299616. please guide me