Patent ID: 7597537

Claim:
A thermal control apparatus comprising: 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, the annular spray tube being circumscribed about an axis and elongated radially inwardly, and the annular spray tube having a generally light bulb cross-sectional shape with a circular radially outer cross-sectional portion connected to a smaller circular radially inner cross-sectional portion by a transition section, the circular radially outer cross-sectional portion having a cross-sectional first diameter, the circular radially inner cross-sectional portion having a cross-sectional second diameter, the transition section having a radially outer maximum cross-sectional third diameter and a radially inner minimum cross-sectional fourth diameter, and the cross-sectional second diameter, the cross-sectional third diameter, and the cross-sectional fourth diameter all being substantially smaller than the cross-sectional first diameter.