Airship Hull Design with Rigid Aeroshell Frame
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Solution Overview
Problem
Conventional airship designs face limitations due to excessive weight, limited aerodynamic lift, and the need for ballast, which restricts payload capacity and operational utility, especially when attempting to incorporate aerodynamic lift in hybrid airships.
Innovation Solution
A lightweight airship hull design featuring a rigid internal main frame, a semi-rigid membrane skin, and a rigid aeroshell frame that interposes between the main frame and skin, capable of handling primary moment and shear loads, aerodynamic pressure loads, and hoop tension from helium pressure.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Strength
If a rigid internal framework is used to support aerodynamic loads, then structural strength is improved, but weight increases excessively
Solution Approach 1:
The hull structure is segmented into three distinct functional components: an internal framework for moment and shear loads, an aeroshell frame for aerodynamic pressure loads, and a membrane skin for hoop tension. This segmentation allows each component to be optimized for its specific load type, preventing unnecessary weight from components carrying loads they don't need to support.
Solution Approach 2:
The patent employs composite structural systems where different materials and structural forms work together: the internal framework uses high-strength materials for bending moments, the aeroshell frame provides rigid pressure containment, and the membrane skin handles tensile hoop stresses. This composite approach achieves superior strength-to-weight ratio compared to conventional single-structure designs.
2Ease of manufacture
If a cigar-shaped hull is used, then conventional structural simplicity is maintained, but aerodynamic lift capability is limited
Solution Approach 1:
The aeroshell frame is designed with an ellipsoidal cross-section rather than a circular one, optimizing aerodynamic lift generation. The curved, streamlined shape reduces drag and increases lift capability while the rigid aeroshell frame maintains this aerodynamic form under pressure loads, something flexible membranes cannot achieve.
Solution Approach 2:
The aeroshell frame serves multiple functions simultaneously: it provides the aerodynamic lifting surface, contains the aerodynamic pressure loads, and transfers these loads to the internal framework. This multi-functionality eliminates the need for separate structures for each function, maintaining manufacturing simplicity while achieving superior aerodynamic performance.
3Weight of moving object
If lifting gas pressure is used to maintain hull shape, then structural weight is reduced, but forward airspeed is limited due to deformation
Solution Approach 1:
The patent applies different structural qualities to different parts of the hull: the aeroshell frame provides rigid, localized support where aerodynamic pressure acts, preventing deformation at critical areas. This localized rigidity allows the rest of the structure to remain lightweight while maintaining shape integrity at high speeds.
Solution Approach 2:
The aeroshell frame is pre-configured with the optimal aerodynamic shape and rigidly supports the membrane skin before aerodynamic loads are applied. This preliminary structural support ensures the hull maintains its designed shape under flight conditions, preventing the deformation that would occur with pressure-only support at high speeds.
4Strength
If conventional aircraft technology is used for lifting body airships, then aerodynamic lift is achieved, but hull weight becomes excessive rendering the design nonfunctional
Solution Approach 1:
The patent segments the load-bearing functions into three distinct structures, each optimized for its specific load type. This prevents the excessive weight that would result from using conventional aircraft technology where a single rigid structure must handle all load types simultaneously.
Solution Approach 2:
The patent changes the structural parameters by introducing the aeroshell frame as an intermediate rigid structure between the internal framework and membrane skin. This parameter change allows the membrane to be supported at optimal intervals, reducing the required thickness and strength (and thus weight) of each component while maintaining overall structural integrity under aerodynamic loads.
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 design enables a practical, cost-effective lifting body airship that can withstand aerodynamic loads, allowing for heavier payloads and reduced operational complexity, while maintaining structural integrity and aerodynamic efficiency.
Implementation Method 1
Airships generate buoyant lift by displacing the surrounding air with a hull containing a lighter than air gas
Implementation Method 2
the lifting gas has a small positive pressure which maintains the hull's shape
Data Source
AI summary
An airship hull is provided that is sufficiently light and cost effective so as to make lifting body type airships practical vehicles for carrying people and cargo. The present invention hull design includes three main structural features, i.e., a rigid internal main frame which carries all primary moment and shear loads induced in the vehicle, the vehicle's skin which forms a semi-rigid barrier membrane for the lighter-than-air lifting gas, and a rigid aeroshell frame interposed between the main frame and the skin. The aeroshell frame and skin, in combination, are referred to as the aeroshell. The aeroshell carries the aerodynamic pressure loads induced on the airship.