Windage Blocker Layout for Bearing Compartment Oil Drainback
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Solution Overview
Problem
Oil loss from bearing compartments in gas turbine engines, particularly at seal locations, leads to performance and operational issues, including imbalance and thermal effects due to oil weeping into compressor and turbine systems.
Innovation Solution
An oil drainback system incorporating a windage blocker positioned upstream of the drain hole in the gutter section, which creates a calming area and increases pressure to facilitate efficient drainage, utilizing a pin or machined feature to direct oil back into the bearing compartment, reducing windage and promoting recirculation.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Productivity
If a drain hole is provided in the gutter section to drain wept oil, then oil drainage capability is improved, but windage forces prevent oil from reaching the drain hole
Solution Approach 1:
A windage blocker is introduced as an intermediary component between the gutter section and the drain hole. This blocker serves as a mediator that counteracts the harmful windage forces by creating a recirculation zone, allowing oil to overcome the windage barrier and reach the drain hole effectively.
Solution Approach 2:
The windage blocker converts the harmful windage forces into a beneficial recirculation pattern. By strategically positioning the blocker upstream of the drain hole, the windage-induced flow is redirected to create a recirculation zone that actively pushes oil toward the drain hole, transforming the harmful effect into a drainage-assisting mechanism.
2Productivity
If the windage blocker is positioned upstream of the drain hole, then oil drainage efficiency is improved, but the device complexity increases
Solution Approach 1:
The gutter section is segmented by introducing a discrete windage blocker element positioned upstream of the drain hole. This segmentation creates distinct functional zones: a recirculation zone upstream of the blocker and a drainage zone at the drain hole, allowing optimized oil flow management without redesigning the entire gutter structure.
Solution Approach 2:
The windage blocker utilizes the existing windage forces and oil flow dynamics within the bearing compartment to create its own recirculation zone. The component does not require external power or complex actuation mechanisms; it passively harnesses the operational conditions to generate the desired oil recirculation and drainage effect.
Applied Scientific Principles
This section explains which scientific principles are used to turn an abstract innovation direction into a practical engineering solution.
Function Achieved in This Case
The windage blocker effectively captures and recirculates wept oil, reducing windage energy and enhancing drainage efficiency, thereby preventing oil from entering the engine gas path and maintaining engine performance and durability.
Implementation Method 1
creating both a calming area for oil to pool and build head pressure for the oil to drain down the drain hole
Implementation Method 2
the presence of the windage blocker changes the oil concentration circumferentially around the gutter section and removes windage energy from the oil
Data Source
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AI summary
A scupper (82) suitable for a bearing compartment of a gas turbine engine includes a windage blocker (100) in a gutter section (84) upstream of a drain hole (102), the windage blocker (100) extends from a wall (110) of the gutter section (84). A method for capturing wept oil in a bearing compartment of a gas turbine engine includes positioning a windage blocker (100) adjacent to a drain hole (102) forming a passage space (112) and increasing a pressure upstream of the windage blocker (100) to generate a vortex (116) downstream of the windage blocker (100) creating an oil re-circulation zone promoting oil drainage into the drain hole (102).