Thermal control of gas turbine engine rings for active clearance control

A gas turbine engine thermal control apparatus includes at least one annular spray tube having spray holes oriented to impinge thermal control air onto a fillet between an outer casing and a forward thermal control ring and, in a more particular embodiment, into a center of the fillet. The apparatus may include an annular segmented stator shroud attached to the outer casing and circumscribing radial outer blade tips of turbine blades of a turbine rotor. A thermal air distribution manifold encircling a portion of the outer casing includes an annular supply tube connected in fluid supply relationship to plenums of header assemblies. The annular spray tube is connected to at least one of the plenums and may be elongated radially inwardly and axially. Baffles attached to radially outwardly facing surfaces of the panels may be contoured to form exhaust passages having exhaust passage inlets and outlets between the baffles and the panels.