Blade Balancing by Mass Sorting and Four-Lobe Distribution
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Current methods for balancing aircraft engine blades are inefficient due to high calculation times and inability to account for centrifugal forces and out-of-balance issues in bare disks, leading to potential disk deformations and premature wear.
Innovation Solution
A method involving sorting blades by mass and distributing them into four lobes (two large and two small) to minimize calculation time and optimize blade placement, reducing centrifugal pressure and preventing disk deformations, while using iterative permutation processes to achieve radial balance.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Productivity
If algorithms for balancing turbine fans are used, then the balancing speed is improved, but they cannot account for centrifugal forces and out-of-balances in bare disks
Solution Approach 1:
The patent segments the balancing problem into two distinct parts: (1) a rapid heuristic algorithm for initial blade arrangement that provides high productivity, and (2) a precise calculation model that accounts for centrifugal forces and bare disk out-of-balances to ensure reliability. This segmentation allows each part to optimize for its specific function without compromise.
Solution Approach 2:
The patent applies preliminary action by first using the fast heuristic algorithm to obtain an initial blade arrangement, then using this result as the starting point for the more accurate but time-consuming centrifugal force calculation. This preliminary step reduces the overall computation time while still achieving high precision in the final result.
2Loss of time
If NP-hard heuristic algorithms are used, then calculation time is reduced, but they cannot take account of pressures on disks due to centrifugal forces
Solution Approach 1:
The patent applies partial action by implementing a two-stage approach where the first stage (heuristic algorithm) provides a sufficiently good initial solution quickly, and the second stage (precise calculation) applies only when necessary to achieve the required precision. This avoids the excessive computation time of always using the most accurate method.
Solution Approach 2:
The heuristic algorithm performs preliminary arrangement of blades to create an initial configuration that is then refined by the precise calculation method. This preliminary action significantly reduces the computational burden of the subsequent precision optimization.
3Reliability
If blades are not properly balanced, then disk deformations and cracks may occur, but proper balancing requires complex algorithms with high calculation times
Solution Approach 1:
The patent segments the balancing process into an efficient initial arrangement phase using heuristic methods and a reliability assurance phase using precise centrifugal force calculations. This ensures disk integrity through the second phase while maintaining productivity through the optimized first phase.
Solution Approach 2:
The patent performs preliminary blade arrangement using fast heuristic algorithms to create an initial configuration that satisfies basic balancing requirements, then applies precise calculations to ensure disk integrity under centrifugal forces. This preliminary action maintains both efficiency and reliability.
Data Source
AI summary
A method for balancing a set of blades intended to be arranged on a bare disc of an aircraft engine, the bare disc comprising a defined number of numbered cells (ai) intended to receive the same defined number of blades, which can have a spread of mass, the method comprising the following steps:—sorting the blades by monotonic order of their mass (mi) to form an ordered set of blades,—separating the ordered set of blades in a balanced manner into four lobes constituted by a first large lobe, by a second large lobe, by a first small lobe and by a second small lobe, the blades being classified into each lobe according to a current placement order, and—arranging the four lobes on the bare disc by making the current placement order of the blades correspond to the numbered cells of the bare disc.