Annular Oil Tank Layout for Reduced Gas Turbine Engine Diameter
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Solution Overview
Problem
Current aircraft gas turbine engines have large accessories on their outer peripheral surfaces, which project radially and increase the frontal projected area, making it difficult to reduce the diameter of the engine.
Innovation Solution
The gas turbine engine incorporates an oil tank that is arranged along the outer peripheral surface of the cylindrical external case, surrounding it to minimize radial projection and reduce the engine's diameter.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Ease of manufacture
If accessories are disposed on the outer peripheral surface of the casing, then the engine can accommodate necessary components, but the accessories project radially and increase the frontal projected area
Solution Approach 1:
The oil tank is nested within the annular space between the external case and the internal case, utilizing the existing structural voids. This nesting approach allows the oil tank to be accommodated without adding external radial projection, as it fits within the existing annular region defined by the two cases.
Solution Approach 2:
Instead of placing the oil tank in the radial direction (external periphery), the invention relocates it to the axial dimension by positioning it between the internal and external cases. This dimensional shift moves the component from a radial arrangement that increases frontal area to an axial arrangement that utilizes the depth of the engine structure.
2Object-affected harmful factors
If the frontal projected area is reduced, then the aerodynamic efficiency is improved, but the space for accessories becomes limited
Solution Approach 1:
The engine structure is segmented into an internal case and an external case, creating distinct spatial zones. The annular space between these segmented components is utilized to house the oil tank, thereby preserving the compact external dimensions while providing adequate space for accessories within the segmented structure.
Solution Approach 2:
The annular space between the internal and external cases serves multiple functions: it provides structural support as part of the engine casing, contains the oil tank for lubrication, and maintains the overall compact geometry. This multi-functional use of space allows accessory accommodation without increasing the frontal projected area.
Data Source
Figure 1
Figure 2
AI summary
A gas turbine engine according to one aspect of the present invention includes: an oil tank storing lubricating oil; and a cylindrical external case accommodating a compressor, a combustor, and a turbine. The oil tank is arranged along an outer peripheral surface of the external case so as to surround the external case.