Geared Turbofan Gearbox Rating for Oil Flow and Sizing
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Solution Overview
Problem
Geared turbofan engines face complexity and inefficiencies in development and manufacturing due to the introduction of a gearbox, necessitating improved methods for designing and producing these engines more efficiently and precisely.
Innovation Solution
The introduction of a gearbox efficiency rating (GER) formula, Q(D1.56T)1.53, which calculates oil flow rate based on gearbox oil flow rate, fan blade diameter, and net thrust, aids in simplifying gearbox development and determining suitable engine configurations, allowing for more precise and efficient turbomachine engine design.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Use of energy by moving object
If a gearbox is introduced in a turbofan engine to allow power turbine and bypass fan to operate at different rotational speeds for maximum efficiency, then operational efficiency and power production are improved, but device complexity and manufacturing difficulty increase significantly
Solution Approach 1:
The patent introduces a gearbox efficiency rating parameter that quantifies the relationship between gearbox oil flow rate, fan blade diameter, and net thrust. This parameter change allows engineers to optimize gearbox operations by adjusting oil flow rates based on specific operating conditions, thereby maintaining high operational efficiency while managing the complexity through standardized performance metrics.
2Power
If a gearbox is introduced in a turbofan engine to allow power turbine and bypass fan to operate at different rotational speeds, then power production is improved, but manufacturing difficulty increases significantly
Solution Approach 1:
The patent establishes the gearbox efficiency rating as a predetermined parameter that can be used during the design and development phases. By calculating and setting appropriate oil flow rates based on this rating before actual manufacturing, engineers can plan manufacturing processes more effectively, reducing the difficulty of producing geared turbofan engines while maintaining high power production capabilities.
3Productivity
If a gearbox efficiency rating formula is introduced to calculate oil flow rate based on gearbox oil flow rate, fan blade diameter, and net thrust, then development efficiency is improved, but measurement and calculation complexity increases
Solution Approach 1:
The gearbox efficiency rating formula serves multiple functions: it characterizes gearbox performance, determines appropriate oil flow rates, and facilitates engine development comparisons. This universal parameter reduces the need for separate measurements and calculations for different development stages, thereby improving overall development efficiency while managing measurement complexity through a consolidated approach.
Data Source
AI summary
A turbomachine engine can include a fan assembly, a vane assembly, a core engine, a gearbox, and a gearbox efficiency rating. The fan assembly can include a plurality of fan blades. The vane assembly can include a plurality of vanes, and the vanes can, in some instances, be disposed aft of the fan blades. The core engine can include one or more compressor sections and one or more turbine sections. The gearbox includes an input and an output. The input is coupled to the one or more turbine sections of the core engine and comprises a first rotational speed, the output is coupled to the fan assembly and has a second rotational speed, and a gear ratio of the first rotational speed to the second rotational speed is within a range of 4.1-14.0. The gearbox efficiency rating is 0.10-1.8.