Flat Kinked Rear Pressure Bulkhead for Aircraft Fuselage
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Solution Overview
Problem
Existing rear pressure bulkheads in commercial aircraft, whether curved or flat, inefficiently utilize space by not allowing optimal allocation between pressurized and unpressurized compartments, leading to oversizing and increased weight and drag.
Innovation Solution
A flat kinked rear pressure bulkhead design with upper and lower flat portions forming kinks contiguous to the rear border of the pressurized cabin, allowing for improved space optimization, easier manufacturing, and enhanced bending inertia, using either metallic or composite materials with sandwich-type panels and monolithic structures.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Strength
If a curved rear pressure bulkhead is used, then the structural strength is improved, but the manufacturing complexity and assembly difficulty increase
Solution Approach 1:
The bulkhead is divided into multiple flat portions (first, second, third flat portions) connected by kinks, transforming a complex curved structure into simpler flat segments that are easier to manufacture and assemble while maintaining structural integrity
Solution Approach 2:
The invention transitions from a two-dimensional curved surface to a three-dimensional kinked structure with flat portions at different orientations, achieving enhanced bending inertia and structural strength through spatial arrangement rather than curvature
2Ease of manufacture
If a flat rear pressure bulkhead is used, then the manufacturing ease is improved, but the bending inertia and structural efficiency decrease
Solution Approach 1:
The bulkhead utilizes three-dimensional spatial arrangement with flat portions oriented at different angles (first flat portion perpendicular to longitudinal axis, second flat portion at 30-60° angle, third flat portion parallel to floor), creating enhanced bending inertia through geometric configuration rather than curvature
Solution Approach 2:
While maintaining flat surfaces for manufacturing ease, the invention introduces kinks (angular changes) between flat portions that provide structural efficiency and bending resistance, achieving a balance between flat geometry and curved-like performance
3Strength
If a conventional rear pressure bulkhead design is used, then the structural separation is achieved, but the space utilization in pressurized and unpressurized compartments is suboptimal
Solution Approach 1:
The kinked configuration with flat portions at different orientations creates additional volumetric space in the unpressurized rear end section, allowing better space utilization for systems while maintaining effective structural separation between pressurized and unpressurized compartments
Data Source
Figure 1~3b
Figure 4~8
AI summary
The invention provides an aircraft fuselage (10) comprising a pressurized cabin (13) and an unpressurized rear section (15) separated by a rear pressure bulkhead (12) that comprises flat portions forming one or more kinks between them, one of said kinks being contiguous to the rear border (19) of the floor (17) that divides the space of the pressurized cabin (13) into upper and lower compartments (21, 23).