Study of the influence of groove geometric parameters on the outer surface of the turbine casing on radial clearance control effectiveness

An analysis of the effectiveness of the active radial clearance control system for the low-pressure turbine of an aircraft gas turbine engine, featuring an annular groove on the outer surface of the casing, has been conducted. Using FSI calculations, the cooling intensity and the regulation range of the radial clearance are evaluated. The results show that jet cooling of the casing with an annular groove enhances the cooling effect and enables a reduction of the turbine radial clearance by 0.5 to 0.6 mm. The selection of an optimal groove geometry can improve this effect by 10% to 20%. Based on the obtained calculation results, a number of design measures are proposed for the active radial clearance control system in turbines with single and double walls.