| 摘要 |
FIELD: engines and pumps.SUBSTANCE: at adjustment of an impeller of a gas-turbine engine, experimental tests are performed and necessity of adjustment is determined as a result of detection of excitation oscillations leading to damage to a lock-on connection on rotating blades. After necessity of adjustment of a gas-turbine engine is determined, the most effective version of undercutting of nozzle blades is determined, which consists in minimum reduction of efficiency of the gas-turbine engine. The first version of undercutting consists in oblique undercutting of an exit edge of the nozzle blade so that an undercutting angle increases from the end part of the feather with maximum undercutting depth at the root part of the feather, which does not exceed 10% of chord of the feather profile of the nozzle blade. The second version of undercutting consists in oblique undercutting of the exit edge of the nozzle blade so that the undercutting angle increases from the root part of the feather with maximum undercutting depth at the end part of the feather, which does not exceed 10% of chord of the feather profile of the nozzle blade. Blades with the undercutting version with minimum decrease of efficiency are put into an impeller - 60% to 70%, with maximum decrease of efficiency - 30% to 40%. Undercutting is performed according to the obtained calculations and the formed set of nozzle blades is placed in a nozzle assembly depending on location of fire tubes dividing the nozzle assembly into sectors, into each of which a different combination of blades is put. The blade combination is composed of at least four blades of one version of undercutting or both of them. Then, trial operation is performed, at the positive result of which the gas-turbine engine is transferred to a production stage, and when result of the trial operation is negative, other versions of arrangement of nozzle blades in the nozzle assembly are accepted.EFFECT: invention allows reducing excitation oscillations acting on rotating blades of a gas-turbine engine at insufficient change of its design.5 dwg, 2 tbl |
