FIELD: engines and pumps.
SUBSTANCE: exhaust casing of a gas turbine engine includes a sleeve, an outer shell coaxial to the sleeve and a lot of arms. The sleeve is centred on the axis and carries an annular flange coaxial to the sleeve on each of its front and rear surfaces as to the flow direction. Arms attach the sleeve to the shell; at that, each arm represents the first and the second side surfaces, which are opposite to each other. The sleeve and the outer shell are radially spaced from each other. In radial sectional plane, the first side surface of each arm forms an acute angle with a tangent to external peripheral part of each flange; the angle is enclosed between 60° and 85°. The first side surface of each arm is connected to each flange by means of a connecting root part, the profile of which in radial sectional plane is determined with a spline passing through N test points, where N is an integral number exceeding or equal to 10. Those N test points are determined in the following way: let O be an intersection point in the above radial sectional plane between a straight line that continues the first side surface and the external peripheral part of the flange. Let it be the first segment of the straight line starting at point O and passing along the straight line continuing the above first side surface in the above radial plane; the segment has the length marked with 11, enlaced in the range of 3% to 15% of length L. That segment is divided into N equal pieces by means of N+1 points marked with H(1), H(2), …, H(N+1). Point H(N+1) coincides with the above point O. Let it be the second segment of straight line (B) starting at point O and passing along the tangent at point O to external peripheral part of the above flange in the above radial plane. That segment has the length marked with 12, enclosed in the range of 25% to 50% of 11, and that segment is divided into N equal pieces by means of N+1 points marked with B(1), B(2), …, B(N+1). Point B(N+1) is located at maximum distance from point O. Let D(1), D(2), …, D(N+1) be N+1 straight lines attaching points B(1) to H(1), B(2) to H(2), …, B(N+1) to H(N+1) respectively. N test points are intersection points between D(1) and D(2), between D(2) and D(3), …, and between D(N) and D(N+1).
EFFECT: invention allows increasing service life of the exhaust casing.
2 cl, 4 dwg
