Flattened Corrugated Pipe Geometry for Low-Resistance Airflow
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Solution Overview
Problem
Existing plastic pipes for air-conditioning and ventilation systems lack mechanical stability under pressure loads while maintaining low flow resistance, especially when laid horizontally in building screed.
Innovation Solution
A flexible corrugated pipe with a flattened cross-section and a smooth inner hose, featuring a symmetrical oval cross-section with specific radii of curvature and inner radii of curvature that optimize mechanical stability and flow resistance, and optionally coated with antistatic or antibacterial materials.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Ease of operation
If a corrugated pipe with circular cross-section is used, then the pipe is flexible and easy to install, but the flow resistance is high and mechanical stability under pressure loads is poor
Solution Approach 1:
The patent applies curvature optimization by designing a flattened oval cross-section with specifically optimized radius of curvature ratios. The top wall has a radius of curvature of at least 1.5 but no more than five times the internal height dimension, and the transitions between walls have inner radii of curvature of at least one-sixth of the inside height dimension. This optimized curvature reduces flow resistance while maintaining structural stability.
Solution Approach 2:
The patent changes the geometric parameters of the pipe cross-section from circular to flattened oval with specific dimension ratios. The inner width dimension transverse to the plane of symmetry is greater than the inner height dimension in the plane of symmetry, creating an optimized aspect ratio that reduces flow resistance while the outer height dimension is constrained to not exceed a predetermined dimension for mechanical stability.
2Loss of energy
If a corrugated pipe with oval cross-section and smooth inner wall is used, then flow resistance is reduced, but mechanical stability against pressure loads from above is insufficient
Solution Approach 1:
The patent uses the corrugated outer structure as a flexible shell that provides mechanical stability against external pressure loads from above. The corrugations act as reinforcement that maintains the pipe's shape and structural integrity while allowing the inner smooth wall to optimize flow characteristics. The outer corrugated pipe and inner smooth pipe work together as a composite structure.
Solution Approach 2:
The patent creates a composite pipe structure consisting of an outer corrugated pipe and an inner smooth pipe. This composite design combines the mechanical advantages of the corrugated structure (strength, stability) with the flow advantages of the smooth inner surface (low resistance). The two components work together to simultaneously achieve both flow efficiency and mechanical stability.
3Adaptability or versatility
If the outer height dimension is reduced to fit within screed thickness, then the pipe can be laid horizontally in building screed, but the flow cross-section is reduced
Solution Approach 1:
The patent employs asymmetric cross-sectional design where the pipe is flattened in the vertical direction (height) to accommodate screed thickness constraints, while maintaining or increasing the horizontal dimension (width). This asymmetric orientation allows the pipe to fit within the limited vertical space of building screed while preserving adequate flow cross-section through the horizontal dimension.
Solution Approach 2:
The patent compensates for the reduced vertical dimension by optimizing the horizontal dimension. The inner width dimension transverse to the plane of symmetry is designed to be greater than the inner height dimension, effectively shifting the flow capacity to the horizontal dimension where there is more available space within the screed.
Data Source
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AI summary
The pipe has a base wall (4), side walls (5) and a ceiling wall (6) merged with each other in a cross section in a curve shape such that curve inner radiuses (14A, 14B) are produced in passages between the base wall and the side walls and between the side walls and the ceiling wall. The inner radiuses amount to sixth part of height inner dimension (12). Cross sections of the base wall, the ceiling wall and side walls are limited, where the side walls are arranged between the base wall and the ceiling wall. The ceiling walls are curved externally in a curve-shape.